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STM32L432KB, STM32L432KC Datasheet

STMicroelectronics

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Datasheet

This is information on a product in full production.
May 2018 DS11451 Rev 4 1/156
STM32L432KB STM32L432KC
Ultra-low-power Arm® Cortex®-M4 32-bit MCU+FPU, 100DMIPS,
up to 256KB Flash, 64KB SRAM, USB FS, analog, audio
Datasheet - production data
Features
Ultra-low-power with FlexPowerControl
1.71 V to 3.6 V power supply
-40 °C to 85/105/125 °C temperature range
8 nA Shutdown mode (2 wakeup pins)
28 nA Standby mode (2 wakeup pins)
280 nA Standby mode with RTC
1.0 µA Stop 2 mode, 1.28 µA with RTC
84 µA/MHz run mode
Batch acquisition mode (BAM)
4 µs wakeup from Stop mode
Brown out reset (BOR)
Interconnect matrix
Core: Arm® 32-bit Cortex®-M4 CPU with FPU,
Adaptive real-time accelerator (ART
Accelerator™) allowing 0-wait-state execution
from Flash memory, frequency up to 80 MHz,
MPU, 100DMIPS and DSP instructions
Performance benchmark
1.25 DMIPS/MHz (Drystone 2.1)
273.55 CoreMark® (3.42 CoreMark/MHz @
80 MHz)
Energy benchmark
176.7 ULPBench® score
Clock Sources
32 kHz crystal oscillator for RTC (LSE)
Internal 16 MHz factory-trimmed RC (±1%)
Internal low-power 32 kHz RC (±5%)
Internal multispeed 100 kHz to 48 MHz
oscillator, auto-trimmed by LSE (better than
±0.25 % accuracy)
Internal 48 MHz with clock recovery
2 PLLs for system clock, USB, audio, ADC
Up to 26 fast I/Os, most 5 V-tolerant
RTC with HW calendar, alarms and calibration
Up to 3 capacitive sensing channels
11x timers: 1x 16-bit advanced motor-control,
1x 32-bit and 2x 16-bit general purpose, 2x 16-
bit basic, 2x low-power 16-bit timers (available
in Stop mode), 2x watchdogs, SysTick timer
Memories
Up to 256 KB single bank Flash,
proprietary code readout protection
64 KB of SRAM including 16 KB with
hardware parity check
Quad SPI memory interface
Rich analog peripherals (independent supply)
1x 12-bit ADC 5 Msps, up to 16-bit with
hardware oversampling, 200 µA/Msps
2x 12-bit DAC output channels, low-power
sample and hold
1x operational amplifier with built-in PGA
2x ultra-low-power comparators
14x communication interfaces
USB 2.0 full-speed crystal less solution
with LPM and BCD
1x SAI (serial audio interface)
–2x I2C FM+(1 Mbit/s), SMBus/PMBus
3x USARTs (ISO 7816, LIN, IrDA, modem)
1x LPUART (Stop 2 wake-up)
2x SPIs (and 1x Quad SPI)
CAN (2.0B Active)
SWPMI single wire protocol master I/F
IRTIM (Infrared interface)
14-channel DMA controller
True random number generator
UFQFPN32 (5x5)
www.st.com
STM32L432KB STM32L432KC
2/156 DS11451 Rev 4
CRC calculation unit, 96-bit unique ID
Development support: serial wire debug
(SWD), JTAG, Embedded Trace Macrocell™
All packages are ECOPACK2® compliant
DS11451 Rev 4 3/156
STM32L432KB STM32L432KC Contents
6
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3 Functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.1 Arm® Cortex®-M4 core with FPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2 Adaptive real-time memory accelerator (ART Accelerator™) . . . . . . . . . 14
3.3 Memory protection unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.4 Embedded Flash memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.5 Embedded SRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.6 Firewall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.7 Boot modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.8 Cyclic redundancy check calculation unit (CRC) . . . . . . . . . . . . . . . . . . . 17
3.9 Power supply management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.9.1 Power supply schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.9.2 Power supply supervisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.9.3 Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.9.4 Low-power modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.9.5 Reset mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.10 Interconnect matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.11 Clocks and startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.12 General-purpose inputs/outputs (GPIOs) . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.13 Direct memory access controller (DMA) . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.14 Interrupts and events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.14.1 Nested vectored interrupt controller (NVIC) . . . . . . . . . . . . . . . . . . . . . . 34
3.14.2 Extended interrupt/event controller (EXTI) . . . . . . . . . . . . . . . . . . . . . . 34
3.15 Analog to digital converter (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.15.1 Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.15.2 Internal voltage reference (VREFINT) . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.16 Digital to analog converter (DAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.17 Comparators (COMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.18 Operational amplifier (OPAMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Contents STM32L432KB STM32L432KC
4/156 DS11451 Rev 4
3.19 Touch sensing controller (TSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.20 Random number generator (RNG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.21 Timers and watchdogs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.21.1 Advanced-control timer (TIM1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.21.2 General-purpose timers (TIM2, TIM15, TIM16) . . . . . . . . . . . . . . . . . . . 40
3.21.3 Basic timers (TIM6 and TIM7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.21.4 Low-power timer (LPTIM1 and LPTIM2) . . . . . . . . . . . . . . . . . . . . . . . . 40
3.21.5 Infrared interface (IRTIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.21.6 Independent watchdog (IWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.21.7 System window watchdog (WWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.21.8 SysTick timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.22 Real-time clock (RTC) and backup registers . . . . . . . . . . . . . . . . . . . . . . 42
3.23 Inter-integrated circuit interface (I2C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.24 Universal synchronous/asynchronous receiver transmitter (USART) . . . 44
3.25 Low-power universal asynchronous receiver transmitter (LPUART) . . . . 45
3.26 Serial peripheral interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.27 Serial audio interfaces (SAI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.28 Single wire protocol master interface (SWPMI) . . . . . . . . . . . . . . . . . . . . 47
3.29 Controller area network (CAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.30 Universal serial bus (USB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.31 Clock recovery system (CRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.32 Quad SPI memory interface (QUADSPI) . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.33 Development support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.33.1 Serial wire JTAG debug port (SWJ-DP) . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.33.2 Embedded Trace Macrocell™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4 Pinouts and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5 Memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
6 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.1 Parameter conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.1.1 Minimum and maximum values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.1.2 Typical values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.1.3 Typical curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.1.4 Loading capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
DS11451 Rev 4 5/156
STM32L432KB STM32L432KC Contents
6
6.1.5 Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.1.6 Power supply scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
6.1.7 Current consumption measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
6.2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
6.3 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.3.1 General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.3.2 Operating conditions at power-up / power-down . . . . . . . . . . . . . . . . . . 68
6.3.3 Embedded reset and power control block characteristics . . . . . . . . . . . 68
6.3.4 Embedded voltage reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
6.3.5 Supply current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
6.3.6 Wakeup time from low-power modes and voltage scaling
transition times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.3.7 External clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.3.8 Internal clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.3.9 PLL characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
6.3.10 Flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.3.11 EMC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6.3.12 Electrical sensitivity characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
6.3.13 I/O current injection characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
6.3.14 I/O port characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
6.3.15 NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
6.3.16 Extended interrupt and event controller input (EXTI) characteristics . . 113
6.3.17 Analog switches booster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
6.3.18 Analog-to-Digital converter characteristics . . . . . . . . . . . . . . . . . . . . . 114
6.3.19 Digital-to-Analog converter characteristics . . . . . . . . . . . . . . . . . . . . . 127
6.3.20 Comparator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
6.3.21 Operational amplifiers characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 133
6.3.22 Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
6.3.23 Timer characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
6.3.24 Communication interfaces characteristics . . . . . . . . . . . . . . . . . . . . . . 138
7 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
7.1 UFQFPN32 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
7.2 Thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
7.2.1 Reference document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
8 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Contents STM32L432KB STM32L432KC
6/156 DS11451 Rev 4
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
DS11451 Rev 4 7/156
STM32L432KB STM32L432KC List of tables
8
List of tables
Table 1. STM32L432Kx family device features and peripheral counts. . . . . . . . . . . . . . . . . . . . . . . 11
Table 2. Access status versus readout protection level and execution modes. . . . . . . . . . . . . . . . . 15
Table 3. STM32L432xx modes overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 4. Functionalities depending on the working mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 5. STM32L432xx peripherals interconnect matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 6. DMA implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 7. Temperature sensor calibration values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 8. Internal voltage reference calibration values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 9. Timer feature comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 10. I2C implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Table 11. STM32L432xx USART/LPUART features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 12. SAI implementation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 13. Legend/abbreviations used in the pinout table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Table 14. STM32L432xx pin definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Table 15. Alternate function AF0 to AF7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Table 16. Alternate function AF8 to AF15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Table 17. STM32L432xx memory map and peripheral register boundary addresses . . . . . . . . . . . . 60
Table 18. Voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Table 19. Current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Table 20. Thermal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Table 21. General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Table 22. Operating conditions at power-up / power-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Table 23. Embedded reset and power control block characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 68
Table 24. Embedded internal voltage reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Table 25. Current consumption in Run and Low-power run modes, code with data processing
running from Flash, ART enable (Cache ON Prefetch OFF) . . . . . . . . . . . . . . . . . . . . . . . 73
Table 26. Current consumption in Run and Low-power run modes, code with data processing
running from Flash, ART disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Table 27. Current consumption in Run and Low-power run modes, code with data processing
running from SRAM1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Table 28. Typical current consumption in Run and Low-power run modes, with different codes
running from Flash, ART enable (Cache ON Prefetch OFF) . . . . . . . . . . . . . . . . . . . . . . . 76
Table 29. Typical current consumption in Run and Low-power run modes, with different codes
running from Flash, ART disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Table 30. Typical current consumption in Run and Low-power run modes, with different codes
running from SRAM1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Table 31. Current consumption in Sleep and Low-power sleep modes, Flash ON . . . . . . . . . . . . . . 78
Table 32. Current consumption in Low-power sleep modes, Flash in power-down . . . . . . . . . . . . . . 79
Table 33. Current consumption in Stop 2 mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Table 34. Current consumption in Stop 1 mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Table 35. Current consumption in Stop 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Table 36. Current consumption in Standby mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Table 37. Current consumption in Shutdown mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Table 38. Peripheral current consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Table 39. Low-power mode wakeup timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Table 40. Regulator modes transition times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Table 41. Wakeup time using USART/LPUART. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Table 42. High-speed external user clock characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
List of tables STM32L432KB STM32L432KC
8/156 DS11451 Rev 4
Table 43. Low-speed external user clock characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Table 44. LSE oscillator characteristics (fLSE = 32.768 kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Table 45. HSI16 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Table 46. MSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97
Table 47. HSI48 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Table 48. LSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Table 49. PLL, PLLSAI1 characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Table 50. Flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Table 51. Flash memory endurance and data retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Table 52. EMS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Table 53. EMI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Table 54. ESD absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Table 55. Electrical sensitivities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Table 56. I/O current injection susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Table 57. I/O static characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Table 58. Output voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Table 59. I/O AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Table 60. NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Table 61. EXTI Input Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Table 62. Analog switches booster characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Table 63. ADC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Table 64. Maximum ADC RAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Table 65. ADC accuracy - limited test conditions 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Table 66. ADC accuracy - limited test conditions 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Table 67. ADC accuracy - limited test conditions 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Table 68. ADC accuracy - limited test conditions 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Table 69. DAC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Table 70. DAC accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Table 71. COMP characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Table 72. OPAMP characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Table 73. TS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Table 74. TIMx characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Table 75. IWDG min/max timeout period at 32 kHz (LSI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Table 76. WWDG min/max timeout value at 80 MHz (PCLK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Table 77. I2C analog filter characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Table 78. SPI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Table 79. Quad SPI characteristics in SDR mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Table 80. QUADSPI characteristics in DDR mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Table 81. SAI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Table 82. USB electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Table 83. SWPMI electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Table 84. UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine pitch quad flat
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Table 85. Package thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Table 86. STM32L432xx ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Table 87. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
DS11451 Rev 4 9/156
STM32L432KB STM32L432KC List of figures
9
List of figures
Figure 1. STM32L432xx block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 2. Power supply overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 3. Power-up/down sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 4. Clock tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 5. STM32L432Kx UFQFPN32 pinout(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Figure 6. STM32L432xx memory map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Figure 7. Pin loading conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Figure 8. Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Figure 9. Power supply scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Figure 10. Current consumption measurement scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Figure 11. VREFINT versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Figure 12. High-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Figure 13. Low-speed external clock source AC timing diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Figure 14. Typical application with a 32.768 kHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Figure 15. HSI16 frequency versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Figure 16. Typical current consumption versus MSI frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Figure 17. HSI48 frequency versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Figure 18. I/O input characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Figure 19. I/O AC characteristics definition(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Figure 20. Recommended NRST pin protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Figure 21. ADC accuracy characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Figure 22. Typical connection diagram using the ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Figure 23. 12-bit buffered / non-buffered DAC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Figure 24. SPI timing diagram - slave mode and CPHA = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Figure 25. SPI timing diagram - slave mode and CPHA = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Figure 26. SPI timing diagram - master mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Figure 27. Quad SPI timing diagram - SDR mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Figure 28. Quad SPI timing diagram - DDR mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Figure 29. SAI master timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Figure 30. SAI slave timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Figure 31. UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine pitch quad flat
package outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Figure 32. UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine pitch quad flat
package recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Figure 33. UFQFPN32 marking (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Introduction STM32L432KB STM32L432KC
10/156 DS11451 Rev 4
1 Introduction
This datasheet provides the ordering information and mechanical device characteristics of
the STM32L432xx microcontrollers.
This document should be read in conjunction with the STM32L43xxx/44xxx/45xxx/46xxx
reference manual (RM0394). The reference manual is available from the
STMicroelectronics website www.st.com.
For information on the Arm®(a) Cortex®-M4 core, please refer to the Cortex®-M4 Technical
Reference Manual, available from the www.arm.com website.
a. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.
DS11451 Rev 4 11/156
STM32L432KB STM32L432KC Description
50
2 Description
The STM32L432xx devices are the ultra-low-power microcontrollers based on the high-
performance Arm® Cortex®-M4 32-bit RISC core operating at a frequency of up to 80 MHz.
The Cortex-M4 core features a Floating point unit (FPU) single precision which supports all
Arm® single-precision data-processing instructions and data types. It also implements a full
set of DSP instructions and a memory protection unit (MPU) which enhances application
security.
The STM32L432xx devices embed high-speed memories (Flash memory up to 256 Kbyte,
64 Kbyte of SRAM), a Quad SPI flash memories interface and an extensive range of
enhanced I/Os and peripherals connected to two APB buses, two AHB buses and a 32-bit
multi-AHB bus matrix.
The STM32L432xx devices embed several protection mechanisms for embedded Flash
memory and SRAM: readout protection, write protection, proprietary code readout
protection and Firewall.
The devices offer a fast 12-bit ADC (5 Msps), two comparators, one operational amplifier,
two DAC channels, a low-power RTC, one general-purpose 32-bit timer, one 16-bit PWM
timer dedicated to motor control, four general-purpose 16-bit timers, and two 16-bit low-
power timers.
In addition, up to 3 capacitive sensing channels are available.
They also feature standard and advanced communication interfaces.
Two I2Cs
Two SPIs
Two USARTs and one Low-Power UART.
One SAI (Serial Audio Interfaces)
One CAN
One USB full-speed device crystal less
One SWPMI (Single Wire Protocol Master Interface)
The STM32L432xx operates in the -40 to +85 °C (+105 °C junction), -40 to +105 °C
(+125 °C junction) and -40 to +125 °C (+130 °C junction) temperature ranges from a 1.71 to
3.6 V power supply. A comprehensive set of power-saving modes allows the design of low-
power applications.
Some independent power supplies are supported: analog independent supply input for
ADC, DAC, OPAMP and comparators
The STM32L432xx family offers a single 32-pin package.
Table 1. STM32L432Kx family device features and peripheral counts
Peripheral STM32L432Kx
Flash memory 256KB
SRAM 64KB
Quad SPI Yes
Description STM32L432KB STM32L432KC
12/156 DS11451 Rev 4
Timers
Advanced control 1 (16-bit)
General purpose 2 (16-bit)
1 (32-bit)
Basic 2 (16-bit)
Low -power 2 (16-bit)
SysTick timer 1
Watchdog timers (independent,
window) 2
Comm. interfaces
SPI 2
I2C2
USART
LPUART
2
1
SAI 1
CAN 1
USB FS Yes(1)
SWPMI Yes
RTC Yes
Tamper pins 1
Random generator Yes
GPIOs
Wakeup pins
26
2
Capacitive sensing
Number of channels 3
12-bit ADC
Number of channels
1
10
12-bit DAC channels 2
Analog comparator 2
Operational amplifiers 1
Max. CPU frequency 80 MHz
Operating voltage 1.71 to 3.6 V
Operating temperature
Ambient operating temperature: -40 to 85 °C / -
40 to 105 °C / -40 to 125 °C
Junction temperature: -40 to 105 °C / -40 to
125 °C / -40 to 130 °C
Packages UFQFPN32
1. There is no VDDUSB pin. VDDUSB is connected internally at VDD. To be functional, VDD must be equal to
3.3 V (+/- 10%).
Table 1. STM32L432Kx family device features and peripheral counts (continued)
Peripheral STM32L432Kx
DS11451 Rev 4 13/156
STM32L432KB STM32L432KC Description
50
Figure 1. STM32L432xx block diagram
Note: AF: alternate function on I/O pins.
MSv39215V3
Flash
up to
256 KB
USB FS
GPIO PORT A
AHB/APB2
PA[15:0]
APB260 M Hz
APB1 30MHz
OUT1
ITF
WWDG
OSC32_IN
OSC32_OUT
JTAG & SW
ARM Cortex-M4
80 MHz
FPU
NVIC
ETM
MPU
DMA2
ART
ACCEL/
CACHE
RNG
@ VDDA
BOR
Supply
supervision
PVD, PVM
Int
reset
XTAL 32 kHz
MAN AGT
RTC
FCLK
Standby
interface
IWDG
@VBAT
@ VDD
@VDD
AWU
Reset & clock
control
PCLKx
Voltage
regulator
3.3 to 1.2 V
VDD Power management
@ VDD
RTC_TAMPx
Backup register
AHB bus-matrix
DAC1
DAC2
TIM6
TIM7
TIM2
D-BUS
SRAM 48 KB
APB1 80 MHz (max)
SRAM 16 KB
I-BUS
S-BUS
DMA1
PB[7:3],
PB[1:0]
PC[15:14]
GPIO PORT B
GPIO PORT C
GPIO PORT H
OUT2
16b
16b
32b 4 channels, ETR as AF
AHB/APB1
HCLKx
10 external analog inputs
USAR T 2MBps
Temperature sensor
@ VDDA
Touch sensing controller
1 Group of
3 channels max as AF RC HSI
RC LSI
PLL 1&2
MSI
Quad SPI memory interface D0[3:0],
CLK0,
CS
@ VDDUSB
COMP1
INP, INM, OUT
COMP2
INP, INM, OUT
@ VDDA
FIFO
PHY
AHB1 80 MHz
CRC
APB2 80MHz
AHB2 80 MHz
FIREWALL
@ VDD
DP
DM
VDD = 1.71 to 3.6 V
VSS
TRACECLK
TRACED[3:0]
NJTRST, JTDI,
JTCK/SWCLK
JTDO/SWD, JTDO
ITF
ADC1
NOE
HSI48
LPTIM2 IN1, OUT, ETR as AF
LPTIM1 IN1, IN2, OUT, ETR as AF
SWPMI1 IO
RX, TX, SUSPEND as AF
LPUART1 RX, TX, CTS, RTS as AF
VOUT, VINM, VINP
OpAmp1
@VDDA
FIFO
TX, RX as AF
bxCAN1
SCL, SDA, SMBA as AF
I2C3/SMBUS
I2C1/SMBUS SCL, SDA, SMBA as AF
MOSI, MISO, SCK, NSS as AF
SPI3
USART2 RX, TX, CK, CTS, RTS as AF
smcard
IrDA
CRS CRS_SYNC
VDDA, VSSA
VDD, VSS, NRST
PH[3]
EXT IT. WKUP
26 AF
TIM1 / PWM
3 compl. channels (TIM1_CH[1:3]N),
4 channels (TIM1_CH[1:4]),
ETR, BKIN, BKIN2 as AF
16b
TIM15
2 channels,
1 compl. channel, BKIN as AF 16b
TIM16 16b
1 channel,
1 compl. channel, BKIN as AF
USART1
RX, TX, CK,CTS,
RTS as AF
smcard
IrDA
SPI1
MOSI, MISO,
SCK, NSS as AF
SAI1
MCLK_A, SD_A, FS_A, SCK_A, EXTCLK
MCLK_B, SD_B, FS_B, SCK_B as AF
Functional overview STM32L432KB STM32L432KC
14/156 DS11451 Rev 4
3 Functional overview
3.1 Arm® Cortex®-M4 core with FPU
The Arm® Cortex®-M4 with FPU processor is the latest generation of Arm® processors for
embedded systems. It was developed to provide a low-cost platform that meets the needs of
MCU implementation, with a reduced pin count and low-power consumption, while
delivering outstanding computational performance and an advanced response to interrupts.
The Arm® Cortex®-M4 with FPU 32-bit RISC processor features exceptional code-
efficiency, delivering the high-performance expected from an Arm® core in the memory size
usually associated with 8- and 16-bit devices.
The processor supports a set of DSP instructions which allow efficient signal processing and
complex algorithm execution.
Its single precision FPU speeds up software development by using metalanguage
development tools, while avoiding saturation.
With its embedded Arm® core, the STM32L432xx family is compatible with all Arm® tools
and software.
Figure 1 shows the general block diagram of the STM32L432xx family devices.
3.2 Adaptive real-time memory accelerator (ART Accelerator™)
The ART Accelerator™ is a memory accelerator which is optimized for STM32 industry-
standard Arm® Cortex®-M4 processors. It balances the inherent performance advantage of
the Arm® Cortex®-M4 over Flash memory technologies, which normally requires the
processor to wait for the Flash memory at higher frequencies.
To release the processor near 100 DMIPS performance at 80MHz, the accelerator
implements an instruction prefetch queue and branch cache, which increases program
execution speed from the 64-bit Flash memory. Based on CoreMark benchmark, the
performance achieved thanks to the ART accelerator is equivalent to 0 wait state program
execution from Flash memory at a CPU frequency up to 80 MHz.
3.3 Memory protection unit
The memory protection unit (MPU) is used to manage the CPU accesses to memory to
prevent one task to accidentally corrupt the memory or resources used by any other active
task. This memory area is organized into up to 8 protected areas that can in turn be divided
up into 8 subareas. The protection area sizes are between 32 bytes and the whole 4
gigabytes of addressable memory.
The MPU is especially helpful for applications where some critical or certified code has to be
protected against the misbehavior of other tasks. It is usually managed by an RTOS (real-
time operating system). If a program accesses a memory location that is prohibited by the
MPU, the RTOS can detect it and take action. In an RTOS environment, the kernel can
dynamically update the MPU area setting, based on the process to be executed.
The MPU is optional and can be bypassed for applications that do not need it.
DS11451 Rev 4 15/156
STM32L432KB STM32L432KC Functional overview
50
3.4 Embedded Flash memory
STM32L432xx devices feature up to 256 Kbyte of embedded Flash memory available for
storing programs and data in single bank architecture. The Flash memory contains 128
pages of 2 Kbyte.
Flexible protections can be configured thanks to option bytes:
Readout protection (RDP) to protect the whole memory. Three levels are available:
Level 0: no readout protection
Level 1: memory readout protection: the Flash memory cannot be read from or
written to if either debug features are connected, boot in RAM or bootloader is
selected
Level 2: chip readout protection: debug features (Cortex-M4 JTAG and serial
wire), boot in RAM and bootloader selection are disabled (JTAG fuse). This
selection is irreversible.
Write protection (WRP): the protected area is protected against erasing and
programming. Two areas can be selected, with 2-Kbyte granularity.
Proprietary code readout protection (PCROP): a part of the flash memory can be
protected against read and write from third parties. The protected area is execute-only:
it can only be reached by the STM32 CPU, as an instruction code, while all other
accesses (DMA, debug and CPU data read, write and erase) are strictly prohibited.
The PCROP area granularity is 64-bit wide. An additional option bit (PCROP_RDP)
allows to select if the PCROP area is erased or not when the RDP protection is
changed from Level 1 to Level 0.
Table 2. Access status versus readout protection level and execution modes
Area Protection
level
User execution Debug, boot from RAM or boot
from system memory (loader)
Read Write Erase Read Write Erase
Main
memory
1 Yes Yes Yes No No No
2 Yes Yes Yes N/A N/A N/A
System
memory
1 Yes No No Yes No No
2 Yes No No N/A N/A N/A
Option
bytes
1 Yes Yes Yes Yes Yes Yes
2 Yes No No N/A N/A N/A
Backup
registers
1YesYesN/A
(1)
1. Erased when RDP change from Level 1 to Level 0.
No No N/A(1)
2 Yes Yes N/A N/A N/A N/A
SRAM2
1 Yes Yes Yes(1) No No No(1)
2 Yes Yes Yes N/A N/A N/A
Functional overview STM32L432KB STM32L432KC
16/156 DS11451 Rev 4
The whole non-volatile memory embeds the error correction code (ECC) feature supporting:
single error detection and correction
double error detection.
The address of the ECC fail can be read in the ECC register
3.5 Embedded SRAM
STM32L432xx devices feature 64 Kbyte of embedded SRAM. This SRAM is split into two
blocks:
48 Kbyte mapped at address 0x2000 0000 (SRAM1)
16 Kbyte located at address 0x1000 0000 with hardware parity check (SRAM2).
This memory is also mapped at address 0x2000 C000, offering a contiguous address
space with the SRAM1 (16 Kbyte aliased by bit band)
This block is accessed through the ICode/DCode buses for maximum performance.
These 16 Kbyte SRAM can also be retained in Standby mode.
The SRAM2 can be write-protected with 1 Kbyte granularity.
The memory can be accessed in read/write at CPU clock speed with 0 wait states.
3.6 Firewall
The device embeds a Firewall which protects code sensitive and secure data from any
access performed by a code executed outside of the protected areas.
Each illegal access generates a reset which kills immediately the detected intrusion.
The Firewall main features are the following:
Three segments can be protected and defined thanks to the Firewall registers:
Code segment (located in Flash or SRAM1 if defined as executable protected
area)
Non-volatile data segment (located in Flash)
Volatile data segment (located in SRAM1)
The start address and the length of each segments are configurable:
Code segment: up to 1024 Kbyte with granularity of 256 bytes
Non-volatile data segment: up to 1024 Kbyte with granularity of 256 bytes
Volatile data segment: up to 48 Kbyte with a granularity of 64 bytes
Specific mechanism implemented to open the Firewall to get access to the protected
areas (call gate entry sequence)
Volatile data segment can be shared or not with the non-protected code
Volatile data segment can be executed or not depending on the Firewall configuration
The Flash readout protection must be set to level 2 in order to reach the expected level of
protection.
DS11451 Rev 4 17/156
STM32L432KB STM32L432KC Functional overview
50
3.7 Boot modes
At startup, BOOT0 pin or nSWBOOT0 option bit, and BOOT1 option bit are used to select
one of three boot options:
Boot from user Flash
Boot from system memory
Boot from embedded SRAM
BOOT0 value may come from the PH3-BOOT0 pin or from an option bit depending on the
value of a user option bit to free the GPIO pad if needed.
A Flash empty check mechanism is implemented to force the boot from system flash if the
first flash memory location is not programmed and if the boot selection is configured to boot
from main flash.
The boot loader is located in system memory. It is used to reprogram the Flash memory by
using USART, I2C, SPI or USB FS in Device mode through DFU (device firmware upgrade).
3.8 Cyclic redundancy check calculation unit (CRC)
The CRC (cyclic redundancy check) calculation unit is used to get a CRC code using a
configurable generator polynomial value and size.
Among other applications, CRC-based techniques are used to verify data transmission or
storage integrity. In the scope of the EN/IEC 60335-1 standard, they offer a means of
verifying the Flash memory integrity. The CRC calculation unit helps compute a signature of
the software during runtime, to be compared with a reference signature generated at link-
time and stored at a given memory location.
3.9 Power supply management
3.9.1 Power supply schemes
VDD = 1.71 to 3.6 V: external power supply for I/Os (VDDIO1), the internal regulator and
the system analog such as reset, power management and internal clocks. It is provided
externally through VDD pins.
VDDA = 1.62 V (ADCs/COMPs) / 1.8 (DAC/OPAMP) to 3.6 V: external analog power
supply for ADCs, DAC, OPAMPs, Comparators and Voltage reference buffer. The VDDA
voltage level is independent from the VDD voltage.
Note: When the functions supplied by VDDA or VDDUSB are not used, these supplies should
preferably be shorted to VDD.
Note: If these supplies are tied to ground, the I/Os supplied by these power supplies are not 5 V
tolerant (refer to Table 18: Voltage characteristics).
Note: VDDIOx is the I/Os general purpose digital functions supply. VDDIOx represents VDDIO1, with
VDDIO1 = VDD.
Functional overview STM32L432KB STM32L432KC
18/156 DS11451 Rev 4
Figure 2. Power supply overview
During power-up and power-down phases, the following power sequence requirements
must be respected:
When VDD is below 1 V, other power supplies (VDDA) must remain below VDD +
300 mV.
When VDD is above 1 V, all power supplies are independent.
During the power-down phase, VDD can temporarily become lower than other supplies only
if the energy provided to the MCU remains below 1 mJ; this allows external decoupling
capacitors to be discharged with different time constants during the power- down transient
phase.
MSv39216V3
Low voltage detector
VDDA
VDDA domain
VSS
VDD
VBAT
A/D converters
Comparators
D/A converters
Operational amplifiers
Voltage reference buffer
VDD domain
I/O ring
VSSA
Reset block
Temp. sensor
PLL, HSI, MSI, HSI48
Standby circuitry
(Wakeup logic, IWDG)
Voltage regulator
VDDIO1
LSE crystal 32 K osc
BKP registers
RCC BDCR register
RTC
Backup domain
Core
Memories
Digital peripherals
VCORE domain
VCORE
USB transceivers
VDDUSB
VSS
DS11451 Rev 4 19/156
STM32L432KB STM32L432KC Functional overview
50
Figure 3. Power-up/down sequence
1. VDDX refers to VDDA.
3.9.2 Power supply supervisor
The device has an integrated ultra-low-power brown-out reset (BOR) active in all modes
except Shutdown and ensuring proper operation after power-on and during power down.
The device remains in reset mode when the monitored supply voltage VDD is below a
specified threshold, without the need for an external reset circuit.
The lowest BOR level is 1.71V at power on, and other higher thresholds can be selected
through option bytes.The device features an embedded programmable voltage detector
(PVD) that monitors the VDD power supply and compares it to the VPVD threshold. An
interrupt can be generated when VDD drops below the VPVD threshold and/or when VDD is
higher than the VPVD threshold. The interrupt service routine can then generate a warning
message and/or put the MCU into a safe state. The PVD is enabled by software.
In addition, the device embeds a Peripheral Voltage Monitor which compares the
independent supply voltage VDDA with a fixed threshold in order to ensure that the
peripheral is in its functional supply range.
MSv47490V1
0.3
1
VBOR0
3.6
Operating modePower-on Power-down time
V
VDDX
(1)
VDD
Invalid supply area VDDX < VDD + 300 mV VDDX independent from VDD
Functional overview STM32L432KB STM32L432KC
20/156 DS11451 Rev 4
3.9.3 Voltage regulator
Two embedded linear voltage regulators supply most of the digital circuitries: the main
regulator (MR) and the low-power regulator (LPR).
The MR is used in the Run and Sleep modes and in the Stop 0 mode.
The LPR is used in Low-Power Run, Low-Power Sleep, Stop 1 and Stop 2 modes. It is
also used to supply the 16 Kbyte SRAM2 in Standby with SRAM2 retention.
Both regulators are in power-down in Standby and Shutdown modes: the regulator
output is in high impedance, and the kernel circuitry is powered down thus inducing
zero consumption.
The ultralow-power STM32L432xx supports dynamic voltage scaling to optimize its power
consumption in run mode. The voltage from the Main Regulator that supplies the logic
(VCORE) can be adjusted according to the system’s maximum operating frequency.
There are two power consumption ranges:
Range 1 with the CPU running at up to 80 MHz.
Range 2 with a maximum CPU frequency of 26 MHz. All peripheral clocks are also
limited to 26 MHz.
The VCORE can be supplied by the low-power regulator, the main regulator being switched
off. The system is then in Low-power run mode.
Low-power run mode with the CPU running at up to 2 MHz. Peripherals with
independent clock can be clocked by HSI16.
3.9.4 Low-power modes
The ultra-low-power STM32L432xx supports seven low-power modes to achieve the best
compromise between low-power consumption, short startup time, available peripherals and
available wakeup sources.
STM32L432KB STM32L432KC Functional overview
DS11451 Rev 4 21/156
Table 3. STM32L432xx modes overview
Mode Regulator(1) CPU Flash SRAM Clocks DMA & Peripherals(2) Wakeup source Consumption(3) Wakeup time
Run
MR range 1
Yes ON(4) ON Any
All
N/A
97 µA/MHz
N/A
MR range2 All except USB_FS, RNG 84 µA/MHz
LPRun LPR Yes ON(4) ON
Any
except
PLL
All except USB_FS, RNG N/A 94 µA/MHz to Range 1: 4 µs
to Range 2: 64 µs
Sleep
MR range 1
No ON(4) ON(5) Any
All Any interrupt or
event
28 µA/MHz
6 cycles
MR range2 All except USB_FS, RNG 26 µA/MHz
LPSleep LPR No ON(4) ON(5)
Any
except
PLL
All except USB_FS, RNG Any interrupt or
event 29 µA/MHz 6 cycles
Stop 0
MR Range 1
No OFF ON LSE
LSI
BOR, PVD, PVM
RTC, IWDG
COMPx (x=1,2)
DAC1
OPAMPx (x=1)
USARTx (x=1,2)(6)
LPUART1(6)
I2Cx (x=1,3)(7)
LPTIMx (x=1,2)
***
All other peripherals are
frozen.
Reset pin, all I/Os
BOR, PVD, PVM
RTC, IWDG
COMPx (x=1..2)
USARTx (x=1,2)(6)
LPUART1(6)
I2Cx (x=1,3)(7)
LPTIMx (x=1,2)
USB_FS(8)
SWPMI1(9)
108 µA
2.4 µs in SRAM
4.1 µs in Flash
MR Range 2 108 µA
Functional overview STM32L432KB STM32L432KC
22/156 DS11451 Rev 4
Stop 1 LPR No Off ON LSE
LSI
BOR, PVD, PVM
RTC, IWDG
COMPx (x=1,2)
DAC1
OPAMPx (x=1)
USARTx (x=1,2)(6)
LPUART1(6)
I2Cx (x=1,3)(7)
LPTIMx (x=1,2)
***
All other peripherals are
frozen.
Reset pin, all I/Os
BOR, PVD, PVM
RTC, IWDG
COMPx (x=1..2)
USARTx (x=1,2)(6)
LPUART1(6)
I2Cx (x=1,3)(7)
LPTIMx (x=1,2)
USB_FS(8)
SWPMI1(9)
4.34 µA w/o RTC
4.63 µA w RTC
6.3 µs in SRAM
7.8 µs in Flash
Stop 2 LPR No Off ON LSE
LSI
BOR, PVD, PVM
RTC, IWDG
COMPx (x=1..2)
I2C3(7)
LPUART1(6)
LPTIM1
***
All other peripherals are
frozen.
Reset pin, all I/Os
BOR, PVD, PVM
RTC, IWDG
COMPx (x=1..2)
I2C3(7)
LPUART1(6)
LPTIM1
1.3 µA w/o RTC
1.4 µA w/RTC
6.8 µs in SRAM
8.2 µs in Flash
Table 3. STM32L432xx modes overview (continued)
Mode Regulator(1) CPU Flash SRAM Clocks DMA & Peripherals(2) Wakeup source Consumption(3) Wakeup time
STM32L432KB STM32L432KC Functional overview
DS11451 Rev 4 23/156
Standby
LPR
Power
ed Off Off
SRAM
2 ON
LSE
LSI
BOR, RTC, IWDG
***
All other peripherals are
powered off.
***
I/O configuration can be
floating, pull-up or pull-down
Reset pin
5 I/Os (WKUPx)(10)
BOR, RTC, IWDG
0.20 µA w/o RTC
0.46 µA w/ RTC
12.2 µs
OFF
Power
ed
Off
0.03 µA w/o RTC
0.29 µA w/ RTC
Shutdown OFF Power
ed Off Off
Power
ed
Off
LSE
RTC
***
All other peripherals are
powered off.
***
I/O configuration can be
floating, pull-up or pull-
down(11)
Reset pin
5 I/Os (WKUPx)(10)
RTC
0.01 µA w/o RTC
0.20 µA w/ RTC 262 µs
1. LPR means Main regulator is OFF and Low-power regulator is ON.
2. All peripherals can be active or clock gated to save power consumption.
3. Typical current at VDD = 1.8 V, 25°C. Consumptions values provided running from SRAM, Flash memory Off, 80 MHz in Range 1, 26 MHz in Range 2, 2 MHz in
LPRun/LPSleep.
4. The Flash memory can be put in power-down and its clock can be gated off when executing from SRAM.
5. The SRAM1 and SRAM2 clocks can be gated on or off independently.
6. U(S)ART and LPUART reception is functional in Stop mode, and generates a wakeup interrupt on Start, address match or received frame event.
7. I2C address detection is functional in Stop mode, and generates a wakeup interrupt in case of address match.
8. USB_FS wakeup by resume from suspend and attach detection protocol event.
9. SWPMI1 wakeup by resume from suspend.
10. The I/Os with wakeup from Standby/Shutdown capability are: PA0, PC13, PE6, PA2, PC5.
11. I/Os can be configured with internal pull-up, pull-down or floating in Shutdown mode but the configuration is lost when exiting the Shutdown mode.
Table 3. STM32L432xx modes overview (continued)
Mode Regulator(1) CPU Flash SRAM Clocks DMA & Peripherals(2) Wakeup source Consumption(3) Wakeup time
Functional overview STM32L432KB STM32L432KC
24/156 DS11451 Rev 4
By default, the microcontroller is in Run mode after a system or a power Reset. It is up to the
user to select one of the low-power modes described below:
Sleep mode
In Sleep mode, only the CPU is stopped. All peripherals continue to operate and can
wake up the CPU when an interrupt/event occurs.
Low-power run mode
This mode is achieved with VCORE supplied by the low-power regulator to minimize the
regulator's operating current. The code can be executed from SRAM or from Flash,
and the CPU frequency is limited to 2 MHz. The peripherals with independent clock can
be clocked by HSI16.
Low-power sleep mode
This mode is entered from the low-power run mode. Only the CPU clock is stopped.
When wakeup is triggered by an event or an interrupt, the system reverts to the low-
power run mode.
Stop 0, Stop 1 and Stop 2 modes
Stop mode achieves the lowest power consumption while retaining the content of
SRAM and registers. All clocks in the VCORE domain are stopped, the PLL, the MSI RC
and the HSI16 RC are disabled. The LSE or LSI is still running.
The RTC can remain active (Stop mode with RTC, Stop mode without RTC).
Some peripherals with wakeup capability can enable the HSI16 RC during Stop mode
to detect their wakeup condition.
Three Stop modes are available: Stop 0, Stop 1 and Stop 2 modes. In Stop 2 mode,
most of the VCORE domain is put in a lower leakage mode.
Stop 1 offers the largest number of active peripherals and wakeup sources, a smaller
wakeup time but a higher consumption than Stop 2. In Stop 0 mode, the main regulator
remains ON, allowing a very fast wakeup time but with much higher consumption.
The system clock when exiting from Stop 0, Stop 1 or Stop 2 modes can be either MSI
up to 48 MHz or HSI16, depending on software configuration.
Standby mode
The Standby mode is used to achieve the lowest power consumption with BOR. The
internal regulator is switched off so that the VCORE domain is powered off. The PLL, the
MSI RC and the HSI16 RC are also switched off.
The RTC can remain active (Standby mode with RTC, Standby mode without RTC).
The brown-out reset (BOR) always remains active in Standby mode.
The state of each I/O during standby mode can be selected by software: I/O with
internal pull-up, internal pull-down or floating.
After entering Standby mode, SRAM1 and register contents are lost except for registers
in the Backup domain and Standby circuitry. Optionally, SRAM2 can be retained in
Standby mode, supplied by the low-power Regulator (Standby with SRAM2 retention
mode).
The device exits Standby mode when an external reset (NRST pin), an IWDG reset,
WKUP pin event (configurable rising or falling edge), or an RTC event occurs (alarm,
periodic wakeup, timestamp, tamper) or a failure is detected on LSE (CSS on LSE).
The system clock after wakeup is MSI up to 8 MHz.
DS11451 Rev 4 25/156
STM32L432KB STM32L432KC Functional overview
50
Shutdown mode
The Shutdown mode allows to achieve the lowest power consumption. The internal
regulator is switched off so that the VCORE domain is powered off. The PLL, the HSI16,
the MSI and the LSI oscillators are also switched off.
The RTC can remain active (Shutdown mode with RTC, Shutdown mode without RTC).
The BOR is not available in Shutdown mode. No power voltage monitoring is possible
in this mode, therefore the switch to Backup domain is not supported.
SRAM1, SRAM2 and register contents are lost except for registers in the Backup
domain.
The device exits Shutdown mode when an external reset (NRST pin), a WKUP pin
event (configurable rising or falling edge), or an RTC event occurs (alarm, periodic
wakeup, timestamp, tamper).
The system clock after wakeup is MSI at 4 MHz.
Functional overview STM32L432KB STM32L432KC
26/156 DS11451 Rev 4
Table 4. Functionalities depending on the working mode(1)
Peripheral Run Sleep
Low-
power
run
Low-
power
sleep
Stop 0/1 Stop 2 Standby Shutdow
-
Wakeup capability
-
Wakeup capability
-
Wakeup capability
-
Wakeup capability
CPU Y - Y - - -------
Flash memory (up
to 256 KB) O(2) O(2) O(2) O(2) --------
SRAM1 (48 KB) Y Y(3) YY
(3) Y-Y-----
SRAM2 (16 KB) Y Y(3) YY
(3) Y-Y-O
(4) ---
Quad SPI OOOO-
-------
Backup Registers Y Y Y Y Y -Y-Y-Y-
Brown-out reset
(BOR) YYYYYYYYYY- -
Programmable
Voltage Detector
(PVD)
OOOOO
OOO- ---
Peripheral Voltage
Monitor (PVMx;
x=1,3,4)
OOOOO
OOO- ---
DMA O O O O - -------
High Speed Internal
(HSI16) OOOO
(5) -(5) -----
Oscillator RC48 O O - - - -------
High Speed
External (HSE) OOOO-
-------
Low Speed Internal
(LSI) OOOOO
-O-O---
Low Speed External
(LSE) OOOOO
-O-O-O-
Multi-Speed Internal
(MSI) OOOO-
-------
Clock Security
System (CSS) OOOO-
-------
Clock Security
System on LSE OOOOO
OOOOO- -
RTC / Auto wakeup O O O O O OOOOOOO
Number of RTC
Tamper pins 11111O1O1O1O
USB FS O(8) O(8) ---O- -----
DS11451 Rev 4 27/156
STM32L432KB STM32L432KC Functional overview
50
USARTx (x=1,2) O O O O O(6) O(6) ------
Low-power UART
(LPUART) OOOOO
(6) O(6) O(6) O(6) ----
I2Cx (x=1) O O O O O(7) O(7) ------
I2C3 OOOOO
(7) O(7) O(7) O(7) ----
SPIx (x=1,3) O O O O - -------
CAN O O O O - -------
SWPMI1 O O O O - O- -----
SAIx (x=1) O O O O - -------
ADCx (x=1) O O O O - -------
DAC1 O O O O O -------
OPAMPx (x=1) O O O O O -------
COMPx (x=1,2) O O O O O OOO- ---
Temperature sensor O O O O - -------
Timers (TIMx) O O O O - -------
Low-power timer 1
(LPTIM1) OOOOOOOO- ---
Low-power timer 2
(LPTIM2) OOOOO
O- -----
Independent
watchdog (IWDG) OOOOO
OOOOO- -
Window watchdog
(WWDG) OOOO-
-------
SysTick timer O O O O - -------
Touch sensing
controller (TSC) OOOO--------
Random number
generator (RNG) O(8) O(8) ----------
CRC calculation
unit OOOO-
-------
GPIOs O O O O O OOO(9)
2
pins
(10)
(11)
2
pins
(10)
Table 4. Functionalities depending on the working mode(1) (continued)
Peripheral Run Sleep
Low-
power
run
Low-
power
sleep
Stop 0/1 Stop 2 Standby Shutdow
-
Wakeup capability
-
Wakeup capability
-
Wakeup capability
-
Wakeup capability
Functional overview STM32L432KB STM32L432KC
28/156 DS11451 Rev 4
3.9.5 Reset mode
In order to improve the consumption under reset, the I/Os state under and after reset is
“analog state” (the I/O schmitt trigger is disable). In addition, the internal reset pull-up is
deactivated when the reset source is internal.
3.10 Interconnect matrix
Several peripherals have direct connections between them. This allows autonomous
communication between peripherals, saving CPU resources thus power supply
consumption. In addition, these hardware connections allow fast and predictable latency.
Depending on peripherals, these interconnections can operate in Run, Sleep, low-power run
and sleep, Stop 0, Stop 1 and Stop 2 modes.
1. Legend: Y = Yes (Enable). O = Optional (Disable by default. Can be enabled by software). - = Not
available.
2. The Flash can be configured in power-down mode. By default, it is not in power-down mode.
3. The SRAM clock can be gated on or off.
4. SRAM2 content is preserved when the bit RRS is set in PWR_CR3 register.
5. Some peripherals with wakeup from Stop capability can request HSI16 to be enabled. In this case, HSI16
is woken up by the peripheral, and only feeds the peripheral which requested it. HSI16 is automatically put
off when the peripheral does not need it anymore.
6. UART and LPUART reception is functional in Stop mode, and generates a wakeup interrupt on Start,
address match or received frame event.
7. I2C address detection is functional in Stop mode, and generates a wakeup interrupt in case of address
match.
8. Voltage scaling Range 1 only.
9. I/Os can be configured with internal pull-up, pull-down or floating in Standby mode.
10. The I/Os with wakeup from Standby/Shutdown capability are: PA0, PA2.
11. I/Os can be configured with internal pull-up, pull-down or floating in Shutdown mode but the configuration is
lost when exiting the Shutdown mode.
Table 5. STM32L432xx peripherals interconnect matrix
Interconnect source Interconnect
destination Interconnect action
Run
Sleep
Low-power run
Low-power sleep
Stop 0 / Stop 1
Stop 2
TIMx
TIMx Timers synchronization or chaining Y Y Y Y - -
ADCx
DAC1 Conversion triggers Y Y Y Y - -
DMA Memory to memory transfer trigger Y Y Y Y - -
COMPx Comparator output blanking Y Y Y Y - -
TIM15/TIM16 IRTIM Infrared interface output generation Y Y Y Y - -
DS11451 Rev 4 29/156
STM32L432KB STM32L432KC Functional overview
50
COMPx
TIM1
TIM2
Timer input channel, trigger, break from
analog signals comparison YYYY - -
LPTIMERx Low-power timer triggered by analog
signals comparison YYYYYY
(1)
ADCx TIM1 Timer triggered by analog watchdog Y Y Y Y - -
RTC
TIM16 Timer input channel from RTC events Y Y Y Y - -
LPTIMERx Low-power timer triggered by RTC alarms
or tampers YYYYYY
(1)
All clocks sources (internal
and external)
TIM2
TIM15, 16
Clock source used as input channel for
RC measurement and trimming YYYY - -
USB TIM2 Timer triggered by USB SOF Y Y - - - -
CSS
CPU (hard fault)
RAM (parity error)
Flash memory (ECC error)
COMPx
PVD
TIM1
TIM15,16 Timer break Y Y Y Y - -
GPIO
TIMx External trigger Y Y Y Y - -
LPTIMERx External trigger Y Y Y Y Y Y
(1)
ADCx
DAC1 Conversion external trigger Y Y Y Y - -
1. LPTIM1 only.
Table 5. STM32L432xx peripherals interconnect matrix (continued)
Interconnect source Interconnect
destination Interconnect action
Run
Sleep
Low-power run
Low-power sleep
Stop 0 / Stop 1
Stop 2
Functional overview STM32L432KB STM32L432KC
30/156 DS11451 Rev 4
3.11 Clocks and startup
The clock controller (see Figure 4) distributes the clocks coming from different oscillators to
the core and the peripherals. It also manages clock gating for low-power modes and
ensures clock robustness. It features:
Clock prescaler: to get the best trade-off between speed and current consumption,
the clock frequency to the CPU and peripherals can be adjusted by a programmable
prescaler
Safe clock switching: clock sources can be changed safely on the fly in run mode
through a configuration register.
Clock management: to reduce power consumption, the clock controller can stop the
clock to the core, individual peripherals or memory.
System clock source: four different clock sources can be used to drive the master
clock SYSCLK:
High Speed External clock (HSE) can supply a PLL.
16 MHz high-speed internal RC oscillator (HSI16), trimmable by software, that can
supply a PLL
Multispeed internal RC oscillator (MSI), trimmable by software, able to generate
12 frequencies from 100 kHz to 48 MHz. When a 32.768 kHz clock source is
available in the system (LSE), the MSI frequency can be automatically trimmed by
hardware to reach better than ±0.25% accuracy. In this mode the MSI can feed the
USB device. The MSI can supply a PLL.
System PLL which can be fed by HSE, HSI16 or MSI, with a maximum frequency
at 80 MHz.
RC48 with clock recovery system (HSI48): internal RC48 MHz clock source can be
used to drive the USB or the RNG peripherals. This clock can be output on the MCO.
Auxiliary clock source: two ultralow-power clock sources that can be used to drive
the real-time clock:
32.768 kHz low-speed external crystal (LSE), supporting four drive capability
modes. The LSE can also be configured in bypass mode for an external clock.
32 kHz low-speed internal RC (LSI), also used to drive the independent watchdog.
The LSI clock accuracy is ±5% accuracy.
Peripheral clock sources: Several peripherals (USB, RNG, SAI, USARTs, I2Cs,
LPTimers, ADC, SWPMI) have their own independent clock whatever the system clock.
Two PLLs, each having three independent outputs allowing the highest flexibility, can
generate independent clocks for the ADC, the USB/RNG and the SAI.
Startup clock: after reset, the microcontroller restarts by default with an internal 4 MHz
clock (MSI). The prescaler ratio and clock source can be changed by the application
program as soon as the code execution starts.
Clock security system (CSS): this feature can be enabled by software. If a HSE clock
failure occurs, the master clock is automatically switched to HSI16 and a software
DS11451 Rev 4 31/156
STM32L432KB STM32L432KC Functional overview
50
interrupt is generated if enabled. LSE failure can also be detected and generated an
interrupt.
Clock-out capability:
MCO: microcontroller clock output: it outputs one of the internal clocks for
external use by the application. Low frequency clocks (LSI, LSE) are available
down to Stop 1 low power state.
LSCO: low speed clock output: it outputs LSI or LSE in all low-power
modesdown to Standby mode. LSE can also be output on LSCO in Shutdown
mode. LSCO is not available in VBAT mode.
Several prescalers allow to configure the AHB frequency, the high speed APB (APB2) and
the low speed APB (APB1) domains. The maximum frequency of the AHB and the APB
domains is 80 MHz.
Functional overview STM32L432KB STM32L432KC
32/156 DS11451 Rev 4
Figure 4. Clock tree
MSv39217V4
SYSCLK
MCO
LSCO
48 MHz clock to USB, RNG
to IWDG
to RTC
to PWR
HCLK
to AHB bus, core, memory and DMA
FCLK Cortex free running clock
to Cortex system timer
to APB1 peripherals
to APB2 peripherals
PCLK1
PCLK2
LSE
HSI16
SYSCLK to USARTx
x=2..3
to LPUART1
to I2Cx
x=1,2,3
to LPTIMx
x=1,2
SAI1_EXTCLK
to SWPMI
to TIMx
x=2,6,7
OSC32_OUT
OSC32_IN
MSI HSI16
HSE
HSI16
LSI
LSE
HSE
SYSCLK
HSE
MSI
HSI16
LSE OSC
32.768 kHz /32
AHB PRESC
/ 1,2,..512
/ 8
APB1 PRESC
/ 1,2,4,8,16
x1 or x2
HSI16
SYSCLK
LSI
LSE
HSI16
HSI16
APB2 PRESC
/ 1,2,4,8,16
to TIMx
x=1,15,16
x1 or x2
to USART1
LSE
HSI16
SYSCLK
/ M
MSI RC
100 kHz – 48 MHz
HSI RC
16 MHz
Clock detector
CK_IN
/ 1䊻㻝㻢
LSI RC 32 kHz
Clock
source
control
PLLSAI1CLK
PLL48M1CLK
PLLCLK
PLLSAI2CLK
PLL48M2CLK
PLLADC1CLK
HSI48
PLL
PLLSAI1
VCO F
VCO
/ P
/ R
/ Q
/ P
/ Q
/ R
VCO F
VCO
MSI
PLLCLK
to ADC
to SAI1
MSI
SYSCLK
HSI16
HSI RC
48 MHz
CRS
HSI16
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3.12 General-purpose inputs/outputs (GPIOs)
Each of the GPIO pins can be configured by software as output (push-pull or open-drain), as
input (with or without pull-up or pull-down) or as peripheral alternate function. Most of the
GPIO pins are shared with digital or analog alternate functions. Fast I/O toggling can be
achieved thanks to their mapping on the AHB2 bus.
The I/Os alternate function configuration can be locked if needed following a specific
sequence in order to avoid spurious writing to the I/Os registers.
3.13 Direct memory access controller (DMA)
The device embeds 2 DMAs. Refer to Table 6: DMA implementation for the features
implementation.
Direct memory access (DMA) is used in order to provide high-speed data transfer between
peripherals and memory as well as memory to memory. Data can be quickly moved by DMA
without any CPU actions. This keeps CPU resources free for other operations.
The two DMA controllers have 14 channels in total, each dedicated to managing memory
access requests from one or more peripherals. Each has an arbiter for handling the priority
between DMA requests.
The DMA supports:
14 independently configurable channels (requests)
Each channel is connected to dedicated hardware DMA requests, software trigger is
also supported on each channel. This configuration is done by software.
Priorities between requests from channels of one DMA are software programmable (4
levels consisting of very high, high, medium, low) or hardware in case of equality
(request 1 has priority over request 2, etc.)
Independent source and destination transfer size (byte, half word, word), emulating
packing and unpacking. Source/destination addresses must be aligned on the data
size.
Support for circular buffer management
3 event flags (DMA Half Transfer, DMA Transfer complete and DMA Transfer Error)
logically ORed together in a single interrupt request for each channel
Memory-to-memory transfer
Peripheral-to-memory and memory-to-peripheral, and peripheral-to-peripheral
transfers
Access to Flash, SRAM, APB and AHB peripherals as source and destination
Programmable number of data to be transferred: up to 65536.
Table 6. DMA implementation
DMA features DMA1 DMA2
Number of regular channels 7 7
Functional overview STM32L432KB STM32L432KC
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3.14 Interrupts and events
3.14.1 Nested vectored interrupt controller (NVIC)
The devices embed a nested vectored interrupt controller able to manage 16 priority levels,
and handle up to 61 maskable interrupt channels plus the 16 interrupt lines of the Cortex®-
M4.
The NVIC benefits are the following:
Closely coupled NVIC gives low latency interrupt processing
Interrupt entry vector table address passed directly to the core
Allows early processing of interrupts
Processing of late arriving higher priority interrupts
Support for tail chaining
Processor state automatically saved on interrupt entry, and restored on interrupt exit,
with no instruction overhead
The NVIC hardware block provides flexible interrupt management features with minimal
interrupt latency.
3.14.2 Extended interrupt/event controller (EXTI)
The extended interrupt/event controller consists of 34 edge detector lines used to generate
interrupt/event requests and wake-up the system from Stop mode. Each external line can be
independently configured to select the trigger event (rising edge, falling edge, both) and can
be masked independently. A pending register maintains the status of the interrupt requests.
The internal lines are connected to peripherals with wakeup from Stop mode capability. The
EXTI can detect an external line with a pulse width shorter than the internal clock period. Up
to 26 GPIOs can be connected to the 16 external interrupt lines.
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3.15 Analog to digital converter (ADC)
The device embeds a successive approximation analog-to-digital converter with the
following features:
12-bit native resolution, with built-in calibration
5.33 Msps maximum conversion rate with full resolution
Down to 18.75 ns sampling time
Increased conversion rate for lower resolution (up to 8.88 Msps for 6-bit
resolution)
Up to 10 external channels.
4 internal channels: internal reference voltage, temperature sensor, DAC1_OUT1 and
DAC1_OUT2.
Single-ended and differential mode inputs
Low-power design
Capable of low-current operation at low conversion rate (consumption decreases
linearly with speed)
Dual clock domain architecture: ADC speed independent from CPU frequency
Highly versatile digital interface
Single-shot or continuous/discontinuous sequencer-based scan mode: 2 groups
of analog signals conversions can be programmed to differentiate background and
high-priority real-time conversions
ADC supports multiple trigger inputs for synchronization with on-chip timers and
external signals
Results stored into data register or in RAM with DMA controller support
Data pre-processing: left/right alignment and per channel offset compensation
Built-in oversampling unit for enhanced SNR
Channel-wise programmable sampling time
Three analog watchdog for automatic voltage monitoring, generating interrupts
and trigger for selected timers
Hardware assistant to prepare the context of the injected channels to allow fast
context switching
3.15.1 Temperature sensor
The temperature sensor (TS) generates a voltage VTS that varies linearly with temperature.
The temperature sensor is internally connected to the ADC1_IN17 input channel which is
used to convert the sensor output voltage into a digital value.
The sensor provides good linearity but it has to be calibrated to obtain good overall
accuracy of the temperature measurement. As the offset of the temperature sensor varies
from chip to chip due to process variation, the uncalibrated internal temperature sensor is
suitable for applications that detect temperature changes only.
To improve the accuracy of the temperature sensor measurement, each device is
individually factory-calibrated by ST. The temperature sensor factory calibration data are
stored by ST in the system memory area, accessible in read-only mode.
Functional overview STM32L432KB STM32L432KC
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3.15.2 Internal voltage reference (VREFINT)
The internal voltage reference (VREFINT) provides a stable (bandgap) voltage output for
the ADC and Comparators. VREFINT is internally connected to the ADC1_IN0 input
channel. The precise voltage of VREFINT is individually measured for each part by ST
during production test and stored in the system memory area. It is accessible in read-only
mode.
3.16 Digital to analog converter (DAC)
Two 12-bit buffered DAC channels can be used to convert digital signals into analog voltage
signal outputs. The chosen design structure is composed of integrated resistor strings and
an amplifier in inverting configuration.
This digital interface supports the following features:
Up to two DAC output channels
8-bit or 12-bit output mode
Buffer offset calibration (factory and user trimming)
Left or right data alignment in 12-bit mode
Synchronized update capability
Noise-wave generation
Triangular-wave generation
Dual DAC channel independent or simultaneous conversions
DMA capability for each channel
External triggers for conversion
Sample and hold low-power mode, with internal or external capacitor
The DAC channels are triggered through the timer update outputs that are also connected
to different DMA channels.
Table 7. Temperature sensor calibration values
Calibration value name Description Memory address
TS_CAL1
TS ADC raw data acquired at a
temperature of 30 °C (± 5 °C),
VDDA = VREF+ = 3.0 V (± 10 mV)
0x1FFF 75A8 - 0x1FFF 75A9
TS_CAL2
TS ADC raw data acquired at a
temperature of 130 °C (± 5 °C),
VDDA = VREF+ = 3.0 V (± 10 mV)
0x1FFF 75CA - 0x1FFF 75CB
Table 8. Internal voltage reference calibration values
Calibration value name Description Memory address
VREFINT
Raw data acquired at a
temperature of 30 °C (± 5 °C),
VDDA = VREF+ = 3.0 V (± 10 mV)
0x1FFF 75AA - 0x1FFF 75AB
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3.17 Comparators (COMP)
The STM32L432xx devices embed two rail-to-rail comparators with programmable
reference voltage (internal or external), hysteresis and speed (low speed for low-power) and
with selectable output polarity.
The reference voltage can be one of the following:
External I/O
DAC output channels
Internal reference voltage or submultiple (1/4, 1/2, 3/4).
All comparators can wake up from Stop mode, generate interrupts and breaks for the timers
and can be also combined into a window comparator.
3.18 Operational amplifier (OPAMP)
The STM32L432xx embeds one operational amplifier with external or internal follower
routing and PGA capability.
The operational amplifier features:
Low input bias current
Low offset voltage
Low-power mode
Rail-to-rail input
3.19 Touch sensing controller (TSC)
The touch sensing controller provides a simple solution for adding capacitive sensing
functionality to any application. Capacitive sensing technology is able to detect finger
presence near an electrode which is protected from direct touch by a dielectric (glass,
plastic, ...). The capacitive variation introduced by the finger (or any conductive object) is
measured using a proven implementation based on a surface charge transfer acquisition
principle.
The touch sensing controller is fully supported by the STMTouch touch sensing firmware
library which is free to use and allows touch sensing functionality to be implemented reliably
in the end application.
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The main features of the touch sensing controller are the following:
Proven and robust surface charge transfer acquisition principle
Supports up to 3 capacitive sensing channels
Up to 3 capacitive sensing channels can be acquired in parallel offering a very good
response time
Spread spectrum feature to improve system robustness in noisy environments
Full hardware management of the charge transfer acquisition sequence
Programmable charge transfer frequency
Programmable sampling capacitor I/O pin
Programmable channel I/O pin
Programmable max count value to avoid long acquisition when a channel is faulty
Dedicated end of acquisition and max count error flags with interrupt capability
One sampling capacitor for up to 3 capacitive sensing channels to reduce the system
components
Compatible with proximity, touchkey, linear and rotary touch sensor implementation
Designed to operate with STMTouch touch sensing firmware library
Note: The number of capacitive sensing channels is dependent on the size of the packages and
subject to I/O availability.
3.20 Random number generator (RNG)
All devices embed an RNG that delivers 32-bit random numbers generated by an integrated
analog circuit.
3.21 Timers and watchdogs
The STM32L432xx includes one advanced control timers, up to five general-purpose timers,
two basic timers, two low-power timers, two watchdog timers and a SysTick timer. The table
below compares the features of the advanced control, general purpose and basic timers.
Table 9. Timer feature comparison
Timer type Timer Counter
resolution
Counter
type
Prescaler
factor
DMA
request
generation
Capture/
compare
channels
Complementary
outputs
Advanced
control TIM1 16-bit Up, down,
Up/down
Any integer
between 1
and 65536
Yes 4 3
General-
purpose TIM2 32-bit Up, down,
Up/down
Any integer
between 1
and 65536
Yes 4 No
General-
purpose TIM15 16-bit Up
Any integer
between 1
and 65536
Yes 2 1
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3.21.1 Advanced-control timer (TIM1)
The advanced-control timer can each be seen as a three-phase PWM multiplexed on 6
channels. They have complementary PWM outputs with programmable inserted dead-
times. They can also be seen as complete general-purpose timers. The 4 independent
channels can be used for:
Input capture
Output compare
PWM generation (edge or center-aligned modes) with full modulation capability (0-
100%)
One-pulse mode output
In debug mode, the advanced-control timer counter can be frozen and the PWM outputs
disabled to turn off any power switches driven by these outputs.
Many features are shared with those of the general-purpose TIMx timers (described in
Section 3.21.2) using the same architecture, so the advanced-control timer can work
together with the TIMx timers via the Timer Link feature for synchronization or event
chaining.
General-
purpose TIM16 16-bit Up
Any integer
between 1
and 65536
Yes 1 1
Basic TIM6, TIM7 16-bit Up
Any integer
between 1
and 65536
Yes 0 No
Table 9. Timer feature comparison (continued)
Timer type Timer Counter
resolution
Counter
type
Prescaler
factor
DMA
request
generation
Capture/
compare
channels
Complementary
outputs
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3.21.2 General-purpose timers (TIM2, TIM15, TIM16)
There are up to three synchronizable general-purpose timers embedded in the
STM32L432xx (see Table 9 for differences). Each general-purpose timer can be used to
generate PWM outputs, or act as a simple time base.
TIM2
It is a full-featured general-purpose timer:
TIM2 has a 32-bit auto-reload up/downcounter and 32-bit prescaler.
This timer features 4 independent channels for input capture/output compare, PWM or
one-pulse mode output. It can work with the other general-purpose timers via the Timer
Link feature for synchronization or event chaining.
The counter can be frozen in debug mode.
It has independent DMA request generation and support quadrature encoder.
TIM15 and 16
They are general-purpose timers with mid-range features:
They have 16-bit auto-reload upcounters and 16-bit prescalers.
TIM15 has 2 channels and 1 complementary channel
TIM16 has 1 channel and 1 complementary channel
All channels can be used for input capture/output compare, PWM or one-pulse mode
output.
The timers can work together via the Timer Link feature for synchronization or event
chaining. The timers have independent DMA request generation.
The counters can be frozen in debug mode.
3.21.3 Basic timers (TIM6 and TIM7)
The basic timers are mainly used for DAC trigger generation. They can also be used as
generic 16-bit timebases.
3.21.4 Low-power timer (LPTIM1 and LPTIM2)
The devices embed two low-power timers. These timers have an independent clock and are
running in Stop mode if they are clocked by LSE, LSI or an external clock. They are able to
wakeup the system from Stop mode.
LPTIM1 is active in Stop 0, Stop 1 and Stop 2 modes.
LPTIM2 is active in Stop 0 and Stop 1 mode.
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STM32L432KB STM32L432KC Functional overview
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This low-power timer supports the following features:
16-bit up counter with 16-bit autoreload register
16-bit compare register
Configurable output: pulse, PWM
Continuous/ one shot mode
Selectable software/hardware input trigger
Selectable clock source
Internal clock sources: LSE, LSI, HSI16 or APB clock
External clock source over LPTIM input (working even with no internal clock
source running, used by pulse counter application).
Programmable digital glitch filter
Encoder mode (LPTIM1 only)
3.21.5 Infrared interface (IRTIM)
The STM32L432xx includes one infrared interface (IRTIM). It can be used with an infrared
LED to perform remote control functions. It uses TIM15 and TIM16 output channels to
generate output signal waveforms on IR_OUT pin.
3.21.6 Independent watchdog (IWDG)
The independent watchdog is based on a 12-bit downcounter and 8-bit prescaler. It is
clocked from an independent 32 kHz internal RC (LSI) and as it operates independently
from the main clock, it can operate in Stop and Standby modes. It can be used either as a
watchdog to reset the device when a problem occurs, or as a free running timer for
application timeout management. It is hardware or software configurable through the option
bytes. The counter can be frozen in debug mode.
3.21.7 System window watchdog (WWDG)
The window watchdog is based on a 7-bit downcounter that can be set as free running. It
can be used as a watchdog to reset the device when a problem occurs. It is clocked from
the main clock. It has an early warning interrupt capability and the counter can be frozen in
debug mode.
3.21.8 SysTick timer
This timer is dedicated to real-time operating systems, but could also be used as a standard
down counter. It features:
A 24-bit down counter
Autoreload capability
Maskable system interrupt generation when the counter reaches 0.
Programmable clock source
Functional overview STM32L432KB STM32L432KC
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3.22 Real-time clock (RTC) and backup registers
The RTC is an independent BCD timer/counter. It supports the following features:
Calendar with subsecond, seconds, minutes, hours (12 or 24 format), week day, date,
month, year, in BCD (binary-coded decimal) format.
Automatic correction for 28, 29 (leap year), 30, and 31 days of the month.
Two programmable alarms.
On-the-fly correction from 1 to 32767 RTC clock pulses. This can be used to
synchronize it with a master clock.
Reference clock detection: a more precise second source clock (50 or 60 Hz) can be
used to enhance the calendar precision.
Digital calibration circuit with 0.95 ppm resolution, to compensate for quartz crystal
inaccuracy.
One anti-tamper detection pin with programmable filter.
Timestamp feature which can be used to save the calendar content. This function can
be triggered by an event on the timestamp pin, or by a tamper event.
17-bit auto-reload wakeup timer (WUT) for periodic events with programmable
resolution and period.
The RTC and the 32 backup registers are supplied through a switch that takes power from
the VDD supply.
The backup registers are 32-bit registers used to store 128 bytes of user application data
when VDD power is not present. They are not reset by a system or power reset, or when the
device wakes up from Standby or Shutdown mode.
The RTC clock sources can be:
A 32.768 kHz external crystal (LSE)
An external resonator or oscillator (LSE)
The internal low power RC oscillator (LSI, with typical frequency of 32 kHz)
The high-speed external clock (HSE) divided by 32.
The RTC is functional in all low-power modes when it is clocked by the LSE. When clocked
by the LSI, the RTC is functional in all low-power modes except Shutdown mode.
All RTC events (Alarm, WakeUp Timer, Timestamp or Tamper) can generate an interrupt
and wakeup the device from the low-power modes.
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3.23 Inter-integrated circuit interface (I2C)
The device embeds two I2C. Refer to Table 10: I2C implementation for the features
implementation.
The I2C bus interface handles communications between the microcontroller and the serial
I2C bus. It controls all I2C bus-specific sequencing, protocol, arbitration and timing.
The I2C peripheral supports:
I2C-bus specification and user manual rev. 5 compatibility:
Slave and master modes, multimaster capability
Standard-mode (Sm), with a bitrate up to 100 kbit/s
Fast-mode (Fm), with a bitrate up to 400 kbit/s
Fast-mode Plus (Fm+), with a bitrate up to 1 Mbit/s and 20 mA output drive I/Os
7-bit and 10-bit addressing mode, multiple 7-bit slave addresses
Programmable setup and hold times
Optional clock stretching
System Management Bus (SMBus) specification rev 2.0 compatibility:
Hardware PEC (Packet Error Checking) generation and verification with ACK
control
Address resolution protocol (ARP) support
SMBus alert
Power System Management Protocol (PMBusTM) specification rev 1.1 compatibility
Independent clock: a choice of independent clock sources allowing the I2C
communication speed to be independent from the PCLK reprogramming. Refer to
Figure 4: Clock tree.
Wakeup from Stop mode on address match
Programmable analog and digital noise filters
1-byte buffer with DMA capability
Table 10. I2C implementation
I2C features(1)
1. X: supported
I2C1 I2C3
Standard-mode (up to 100 kbit/s) X X
Fast-mode (up to 400 kbit/s) X X
Fast-mode Plus with 20mA output drive I/Os (up to 1 Mbit/s) X X
Programmable analog and digital noise filters X X
SMBus/PMBus hardware support X X
Independent clock X X
Wakeup from Stop 0 / Stop 1 mode on address match X X
Wakeup from Stop 2 mode on address match - X
Functional overview STM32L432KB STM32L432KC
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3.24 Universal synchronous/asynchronous receiver transmitter
(USART)
The STM32L432xx devices have two embedded universal synchronous receiver
transmitters (USART1 and USART2).
These interfaces provide asynchronous communication, IrDA SIR ENDEC support,
multiprocessor communication mode, single-wire half-duplex communication mode and
have LIN Master/Slave capability. They provide hardware management of the CTS and RTS
signals, and RS485 Driver Enable. They are able to communicate at speeds of up to
10Mbit/s.
USART1 and USART2 also provide Smart Card mode (ISO 7816 compliant) and SPI-like
communication capability.
All USART have a clock domain independent from the CPU clock, allowing the USARTx
(x=1,2) to wake up the MCU from Stop mode using baudrates up to 204 Kbaud. The wake
up events from Stop mode are programmable and can be:
Start bit detection
Any received data frame
A specific programmed data frame
All USART interfaces can be served by the DMA controller.
Table 11. STM32L432xx USART/LPUART features
USART modes/features(1)
1. X = supported.
USART1 USART2 LPUART1
Hardware flow control for modem X X X
Continuous communication using DMA X X X
Multiprocessor communication X X X
Synchronous mode X X -
Smartcard mode X X -
Single-wire half-duplex communication X X X
IrDA SIR ENDEC block X X -
LIN mode X X -
Dual clock domain X X X
Wakeup from Stop 0 / Stop 1 modes X X X
Wakeup from Stop 2 mode - - X
Receiver timeout interrupt X X -
Modbus communication X X -
Auto baud rate detection X (4 modes) -
Driver Enable X X X
LPUART/USART data length 7, 8 and 9 bits
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3.25 Low-power universal asynchronous receiver transmitter
(LPUART)
The device embeds one Low-Power UART. The LPUART supports asynchronous serial
communication with minimum power consumption. It supports half duplex single wire
communication and modem operations (CTS/RTS). It allows multiprocessor
communication.
The LPUART has a clock domain independent from the CPU clock, and can wakeup the
system from Stop mode using baudrates up to 220 Kbaud. The wake up events from Stop
mode are programmable and can be:
Start bit detection
Any received data frame
A specific programmed data frame
Only a 32.768 kHz clock (LSE) is needed to allow LPUART communication up to 9600
baud. Therefore, even in Stop mode, the LPUART can wait for an incoming frame while
having an extremely low energy consumption. Higher speed clock can be used to reach
higher baudrates.
LPUART interface can be served by the DMA controller.
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3.26 Serial peripheral interface (SPI)
Two SPI interfaces allow communication up to 40 Mbits/s in master and up to 24 Mbits/s
slave modes, in half-duplex, full-duplex and simplex modes. The 3-bit prescaler gives 8
master mode frequencies and the frame size is configurable from 4 bits to 16 bits. The SPI
interfaces support NSS pulse mode, TI mode and Hardware CRC calculation.
All SPI interfaces can be served by the DMA controller.
3.27 Serial audio interfaces (SAI)
The device embeds 1 SAI. Refer to Table 12: SAI implementation for the features
implementation. The SAI bus interface handles communications between the
microcontroller and the serial audio protocol.
The SAI peripheral supports:
Two independent audio sub-blocks which can be transmitters or receivers with their
respective FIFO.
8-word integrated FIFOs for each audio sub-block.
Synchronous or asynchronous mode between the audio sub-blocks.
Master or slave configuration independent for both audio sub-blocks.
Clock generator for each audio block to target independent audio frequency sampling
when both audio sub-blocks are configured in master mode.
Data size configurable: 8-, 10-, 16-, 20-, 24-, 32-bit.
Peripheral with large configurability and flexibility allowing to target as example the
following audio protocol: I2S, LSB or MSB-justified, PCM/DSP, TDM, AC’97 and SPDIF
out.
Up to 16 slots available with configurable size and with the possibility to select which
ones are active in the audio frame.
Number of bits by frame may be configurable.
Frame synchronization active level configurable (offset, bit length, level).
First active bit position in the slot is configurable.
LSB first or MSB first for data transfer.
Mute mode.
Stereo/Mono audio frame capability.
Communication clock strobing edge configurable (SCK).
Error flags with associated interrupts if enabled respectively.
Overrun and underrun detection.
Anticipated frame synchronization signal detection in slave mode.
Late frame synchronization signal detection in slave mode.
Codec not ready for the AC’97 mode in reception.
Interruption sources when enabled:
–Errors.
FIFO requests.
DMA interface with 2 dedicated channels to handle access to the dedicated integrated
FIFO of each SAI audio sub-block.
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3.28 Single wire protocol master interface (SWPMI)
The Single wire protocol master interface (SWPMI) is the master interface corresponding to
the Contactless Frontend (CLF) defined in the ETSI TS 102 613 technical specification. The
main features are:
full-duplex communication mode
automatic SWP bus state management (active, suspend, resume)
configurable bitrate up to 2 Mbit/s
automatic SOF, EOF and CRC handling
SWPMI can be served by the DMA controller.
3.29 Controller area network (CAN)
The CAN is compliant with specifications 2.0A and B (active) with a bit rate up to 1 Mbit/s. It
can receive and transmit standard frames with 11-bit identifiers as well as extended frames
with 29-bit identifiers. It has three transmit mailboxes, two receive FIFOs with 3 stages and
14 scalable filter banks.
Table 12. SAI implementation
SAI features Support(1)
1. X: supported
I2S, LSB or MSB-justified, PCM/DSP, TDM, AC’97 X
Mute mode X
Stereo/Mono audio frame capability. X
16 slots X
Data size configurable: 8-, 10-, 16-, 20-, 24-, 32-bit X
FIFO Size X (8 Word)
SPDIF X
Functional overview STM32L432KB STM32L432KC
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The CAN peripheral supports:
Supports CAN protocol version 2.0 A, B Active
Bit rates up to 1 Mbit/s
Transmission
Three transmit mailboxes
Configurable transmit priority
Reception
Two receive FIFOs with three stages
14 Scalable filter banks
Identifier list feature
Configurable FIFO overrun
Time-triggered communication option
Disable automatic retransmission mode
16-bit free running timer
Time Stamp sent in last two data bytes
Management
Maskable interrupts
Software-efficient mailbox mapping at a unique address space
3.30 Universal serial bus (USB)
The STM32L432xx devices embed a full-speed USB device peripheral compliant with the
USB specification version 2.0. The internal USB PHY supports USB FS signaling,
embedded DP pull-up and also battery charging detection according to Battery Charging
Specification Revision 1.2. The USB interface implements a full-speed (12 Mbit/s) function
interface with added support for USB 2.0 Link Power Management. It has software-
configurable endpoint setting with packet memory up-to 1 KB and suspend/resume support.
It requires a precise 48 MHz clock which can be generated from the internal main PLL or by
the internal 48 MHz oscillator in automatic trimming mode. The synchronization for this
oscillator can be taken from the USB data stream itself (SOF signalization) which allows
crystal less operation.
3.31 Clock recovery system (CRS)
The STM32L432xx devices embed a special block which allows automatic trimming of the
internal 48 MHz oscillator to guarantee its optimal accuracy over the whole device
operational range. This automatic trimming is based on the external synchronization signal,
which could be either derived from USB SOF signalization, from LSE oscillator, from an
external signal on CRS_SYNC pin or generated by user software. For faster lock-in during
startup it is also possible to combine automatic trimming with manual trimming action.
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3.32 Quad SPI memory interface (QUADSPI)
The Quad SPI is a specialized communication interface targeting single, dual or quad SPI
flash memories. It can operate in any of the three following modes:
Indirect mode: all the operations are performed using the QUADSPI registers
Status polling mode: the external flash status register is periodically read and an
interrupt can be generated in case of flag setting
Memory-mapped mode: the external Flash is memory mapped and is seen by the
system as if it were an internal memory
Both throughput and capacity can be increased two-fold using dual-flash mode, where two
Quad SPI flash memories are accessed simultaneously.
The Quad SPI interface supports:
Three functional modes: indirect, status-polling, and memory-mapped
SDR and DDR support
Fully programmable opcode for both indirect and memory mapped mode
Fully programmable frame format for both indirect and memory mapped mode
Each of the 5 following phases can be configured independently (enable, length,
single/dual/quad communication)
Instruction phase
Address phase
Alternate bytes phase
Dummy cycles phase
Data phase
Integrated FIFO for reception and transmission
8, 16, and 32-bit data accesses are allowed
DMA channel for indirect mode operations
Programmable masking for external flash flag management
Timeout management
Interrupt generation on FIFO threshold, timeout, status match, operation complete, and
access error
Functional overview STM32L432KB STM32L432KC
50/156 DS11451 Rev 4
3.33 Development support
3.33.1 Serial wire JTAG debug port (SWJ-DP)
The Arm® SWJ-DP interface is embedded, and is a combined JTAG and serial wire debug
port that enables either a serial wire debug or a JTAG probe to be connected to the target.
Debug is performed using 2 pins only instead of 5 required by the JTAG (JTAG pins could
be re-use as GPIO with alternate function): the JTAG TMS and TCK pins are shared with
SWDIO and SWCLK, respectively, and a specific sequence on the TMS pin is used to
switch between JTAG-DP and SW-DP.
3.33.2 Embedded Trace Macrocell™
The Arm® Embedded Trace Macrocell™ provides a greater visibility of the instruction and
data flow inside the CPU core by streaming compressed data at a very high rate from the
STM32L432xx through a small number of ETM pins to an external hardware trace port
analyzer (TPA) device. Real-time instruction and data flow activity be recorded and then
formatted for display on the host computer that runs the debugger software. TPA hardware
is commercially available from common development tool vendors.
The Embedded Trace Macrocell™ operates with third party debugger software tools.
DS11451 Rev 4 51/156
STM32L432KB STM32L432KC Pinouts and pin description
62
4 Pinouts and pin description
Figure 5. STM32L432Kx UFQFPN32 pinout(1)
1. The above figure shows the package top view.
MSv37605V2
UFQFPN32
1
2
3
4
5
6
7
8
VDD
PC14-OSC32_IN
PC15-OSC32_OUT
NRST
VDDA/VREF+
PA0/CK_IN
PA1
PA2
24
23
22
21
20
19
18
17
29
27
25
32
31
30
28
26
12
14
16
9
10
11
13
15
PA3
PA4
PA7
VSS
PA5
PA6
PB0
PB1
PA14
PA13
PA12
PA11
PA10
PA9
PA8
VDD
VSS
PH3/BOOT0
PB5
PA15
PB7
PB6
PB4
PB3
Table 13. Legend/abbreviations used in the pinout table
Name Abbreviation Definition
Pin name Unless otherwise specified in brackets below the pin name, the pin function during and after
reset is the same as the actual pin name
Pin type
S Supply pin
I Input only pin
I/O Input / output pin
I/O structure
FT 5 V tolerant I/O
TT 3.6 V tolerant I/O
RST Bidirectional reset pin with embedded weak pull-up resistor
Option for TT or FT I/Os
_f (1) I/O, Fm+ capable
_u (2) I/O, with USB function supplied by VDDUSB
_a (3) I/O, with Analog switch function supplied by VDDA
Notes Unless otherwise specified by a note, all I/Os are set as analog inputs during and after reset.
Pin
functions
Alternate
functions Functions selected through GPIOx_AFR registers
Additional
functions Functions directly selected/enabled through peripheral registers
1. The related I/O structures in Table 14 are: FT_f, FT_fa.
2. The related I/O structures in Table 14 is: FT_u.
3. The related I/O structures in Table 14 are: FT_a, FT_fa, TT_a.
Pinouts and pin description STM32L432KB STM32L432KC
52/156 DS11451 Rev 4
Table 14. STM32L432xx pin definitions
Pin
Number
Pin name
(function after
reset)
Pin type
I/O structure
Notes
Pin functions
UFQFPN32
Alternate functions Additional functions
2
PC14-
OSC32_I
N (PC14)
I/O FT
(1)
(2) EVENTOUT OSC32_IN
3
PC15-
OSC32_
OUT
(PC15)
I/O FT
(1)
(2) EVENTOUT OSC32_OUT
4 NRST I/O RST - - -
5VDDA/VR
EF+ S-- - -
6PA0/
CK_IN I/O FT_a -
TIM2_CH1, USART2_CTS,
COMP1_OUT, SAI1_EXTCLK,
TIM2_ETR, EVENTOUT
OPAMP1_VINP,
COMP1_INM, ADC1_IN5,
RTC_TAMP2, WKUP1,
CK_IN
7 PA1 I/O FT_a -
TIM2_CH2, I2C1_SMBA,
SPI1_SCK,
USART2_RTS_DE,
TIM15_CH1N, EVENTOUT
OPAMP1_VINM,
COMP1_INP, ADC1_IN6
8 PA2 I/O FT_a -
TIM2_CH3, USART2_TX,
LPUART1_TX,
QUADSPI_BK1_NCS,
COMP2_OUT, TIM15_CH1,
EVENTOUT
COMP2_INM, ADC1_IN7,
WKUP4, LSCO
9 PA3 I/O TT_a -
TIM2_CH4, USART2_RX,
LPUART1_RX,
QUADSPI_CLK,
SAI1_MCLK_A, TIM15_CH2,
EVENTOUT
OPAMP1_VOUT,
COMP2_INP, ADC1_IN8
10 PA4 I/O TT_a -
SPI1_NSS, SPI3_NSS,
USART2_CK, SAI1_FS_B,
LPTIM2_OUT, EVENTOUT
COMP1_INM,
COMP2_INM, ADC1_IN9,
DAC1_OUT1
11 PA5 I/O TT_a -
TIM2_CH1, TIM2_ETR,
SPI1_SCK, LPTIM2_ETR,
EVENTOUT
COMP1_INM,
COMP2_INM, ADC1_IN10,
DAC1_OUT2
12 PA6 I/O FT_a -
TIM1_BKIN, SPI1_MISO,
COMP1_OUT, USART3_CTS,
LPUART1_CTS,
QUADSPI_BK1_IO3,
TIM1_BKIN_COMP2,
TIM16_CH1, EVENTOUT
ADC1_IN11
DS11451 Rev 4 53/156
STM32L432KB STM32L432KC Pinouts and pin description
62
13 PA7 I/O FT_fa -
TIM1_CH1N, I2C3_SCL,
SPI1_MOSI,
QUADSPI_BK1_IO2,
COMP2_OUT, EVENTOUT
ADC1_IN12
14 PB0 I/O FT_a -
TIM1_CH2N, SPI1_NSS,
USART3_CK,
QUADSPI_BK1_IO1,
COMP1_OUT, SAI1_EXTCLK,
EVENTOUT
ADC1_IN15
15 PB1 I/O FT_a -
TIM1_CH3N,
USART3_RTS_DE,
LPUART1_RTS_DE,
QUADSPI_BK1_IO0,
LPTIM2_IN1, EVENTOUT
COMP1_INM, ADC1_IN16
16 VSS S - - - -
17 VDD S - - - -
18 PA8 I/O FT -
MCO, TIM1_CH1,
USART1_CK, SWPMI1_IO,
SAI1_SCK_A, LPTIM2_OUT,
EVENTOUT
-
19 PA9 I/O FT_f -
TIM1_CH2, I2C1_SCL,
USART1_TX, SAI1_FS_A,
TIM15_BKIN, EVENTOUT
-
20 PA10 I/O FT_f -
TIM1_CH3, I2C1_SDA,
USART1_RX,
USB_CRS_SYNC,
SAI1_SD_A, EVENTOUT
-
21 PA11 I/O FT_u -
TIM1_CH4, TIM1_BKIN2,
SPI1_MISO, COMP1_OUT,
USART1_CTS, CAN1_RX,
USB_DM,
TIM1_BKIN2_COMP1,
EVENTOUT
-
22 PA12 I/O FT_u -
TIM1_ETR, SPI1_MOSI,
USART1_RTS_DE,
CAN1_TX, USB_DP,
EVENTOUT
-
23
PA13
(JTMS-
SWDIO)
I/O FT (3)
JTMS-SWDIO, IR_OUT,
USB_NOE, SWPMI1_TX,
SAI1_SD_B, EVENTOUT
-
Table 14. STM32L432xx pin definitions (continued)
Pin
Number
Pin name
(function after
reset)
Pin type
I/O structure
Notes
Pin functions
UFQFPN32
Alternate functions Additional functions
Pinouts and pin description STM32L432KB STM32L432KC
54/156 DS11451 Rev 4
24
PA14
(JTCK-
SWCLK)
I/O FT (3)
JTCK-SWCLK, LPTIM1_OUT,
I2C1_SMBA, SWPMI1_RX,
SAI1_FS_B, EVENTOUT
-
25 PA15
(JTDI) I/O FT (3)
JTDI, TIM2_CH1, TIM2_ETR,
USART2_RX, SPI1_NSS,
SPI3_NSS,
USART3_RTS_DE,
TSC_G3_IO1,
SWPMI1_SUSPEND,
EVENTOUT
-
26
PB3
(JTDO-
TRACE
SWO)
I/O FT_a (3)
JTDO-TRACESWO,
TIM2_CH2, SPI1_SCK,
SPI3_SCK,
USART1_RTS_DE,
SAI1_SCK_B, EVENTOUT
COMP2_INM
27 PB4
(NJTRST) I/O FT_fa (3)
NJTRST, I2C3_SDA,
SPI1_MISO, SPI3_MISO,
USART1_CTS, TSC_G2_IO1,
SAI1_MCLK_B, EVENTOUT
COMP2_INP
28 PB5 I/O FT -
LPTIM1_IN1, I2C1_SMBA,
SPI1_MOSI, SPI3_MOSI,
USART1_CK, TSC_G2_IO2,
COMP2_OUT, SAI1_SD_B,
TIM16_BKIN, EVENTOUT
-
29 PB6 I/O FT_fa -
LPTIM1_ETR, I2C1_SCL,
USART1_TX, TSC_G2_IO3,
SAI1_FS_B, TIM16_CH1N,
EVENTOUT
COMP2_INP
30 PB7 I/O FT_fa -
LPTIM1_IN2, I2C1_SDA,
USART1_RX, TSC_G2_IO4,
EVENTOUT
COMP2_INM, PVD_IN
31 PH3/
BOOT0 I/O FT - EVENTOUT BOOT0
32 VSS S - - - -
1VDDS-- - -
1. PC14 and PC15 are supplied through the power switch. Since the switch only sinks a limited amount of
current (3 mA), the use of GPIOs PC14 to PC15 in output mode is limited:
- The speed should not exceed 2 MHz with a maximum load of 30 pF
- These GPIOs must not be used as current sources (e.g. to drive an LED).
2. After a Backup domain power-up, PC14 and PC15 operate as GPIOs. Their function then depends on the
content of the RTC registers which are not reset by the system reset. For details on how to manage these
GPIOs, refer to the Backup domain and RTC register descriptions in the RM0394 reference manual.
3. After reset, these pins are configured as JTAG/SW debug alternate functions, and the internal pull-up on
PA15, PA13, PB4 pins and the internal pull-down on PA14 pin are activated.
Table 14. STM32L432xx pin definitions (continued)
Pin
Number
Pin name
(function after
reset)
Pin type
I/O structure
Notes
Pin functions
UFQFPN32
Alternate functions Additional functions
STM32L432KB STM32L432KC Pinouts and pin description
DS11451 Rev 4 55/156
Table 15. Alternate function AF0 to AF7(1)
Port
AF0 AF1 AF2 AF3 AF4 AF5 AF6 AF7
SYS_AF TIM1/TIM2/
LPTIM1 TIM1/TIM2 USART2 I2C1/I2C2/I2C3 SPI1/SPI2 SPI3
USART1/
USART2/
USART3
Port A
PA0-TIM2_CH1-----USART2_CTS
PA1 - TIM2_CH2 - - I2C1_SMBA SPI1_SCK - USART2_RTS_
DE
PA2-TIM2_CH3-----USART2_TX
PA3-TIM2_CH4-----USART2_RX
PA4 - - - - - SPI1_NSS SPI3_NSS USART2_CK
PA5 - TIM2_CH1 TIM2_ETR - - SPI1_SCK - -
PA6 - TIM1_BKIN - - - SPI1_MISO COMP1_OUT USART3_CTS
PA7 - TIM1_CH1N - - I2C3_SCL SPI1_MOSI - -
PA8MCOTIM1_CH1-----USART1_CK
PA9 - TIM1_CH2 - - I2C1_SCL - - USART1_TX
PA10 - TIM1_CH3 - - I2C1_SDA - - USART1_RX
PA11 - TIM1_CH4 TIM1_BKIN2 - - SPI1_MISO COMP1_OUT USART1_CTS
PA12 - TIM1_ETR - - - SPI1_MOSI - USART1_RTS_
DE
PA13JTMS-SWDIOIR_OUT------
PA14 JTCK-SWCLK LPTIM1_OUT - - I2C1_SMBA - - -
PA15 JTDI TIM2_CH1 TIM2_ETR USART2_RX - SPI1_NSS SPI3_NSS USART3_RTS_
DE
Pinouts and pin description STM32L432KB STM32L432KC
56/156 DS11451 Rev 4
Port B
PB0 - TIM1_CH2N - - - SPI1_NSS - USART3_CK
PB1-TIM1_CH3N-----
USART3_RTS_
DE
PB3 JTDO-
TRACESWO TIM2_CH2 - - - SPI1_SCK SPI3_SCK USART1_RTS_
DE
PB4 NJTRST - - - I2C3_SDA SPI1_MISO SPI3_MISO USART1_CTS
PB5 - LPTIM1_IN1 - - I2C1_SMBA SPI1_MOSI SPI3_MOSI USART1_CK
PB6 - LPTIM1_ETR - - I2C1_SCL - - USART1_TX
PB7 - LPTIM1_IN2 - - I2C1_SDA - - USART1_RX
Port C
PC14--------
PC15--------
Port HPH3--------
1. Please refer to Table 16 for AF8 to AF15.
Table 15. Alternate function AF0 to AF7(1) (continued)
Port
AF0 AF1 AF2 AF3 AF4 AF5 AF6 AF7
SYS_AF TIM1/TIM2/
LPTIM1 TIM1/TIM2 USART2 I2C1/I2C2/I2C3 SPI1/SPI2 SPI3
USART1/
USART2/
USART3
STM32L432KB STM32L432KC Pinouts and pin description
DS11451 Rev 4 57/156
Table 16. Alternate function AF8 to AF15(1)
Port
AF8 AF9 AF10 AF11 AF12 AF13 AF14 AF15
LPUART1 CAN1/TSC USB/QUADSPI -
COMP1/
COMP2/
SWPMI1
SAI1 TIM2/TIM15/
TIM16/LPTIM2 EVENTOUT
Port A
PA0 - - - - COMP1_OUT SAI1_EXTCLK TIM2_ETR EVENTOUT
PA1------TIM15_CH1NEVENTOUT
PA2 LPUART1_TX - QUADSPI_
BK1_NCS - COMP2_OUT - TIM15_CH1 EVENTOUT
PA3 LPUART1_RX - QUADSPI_CLK - - SAI1_MCLK_A TIM15_CH2 EVENTOUT
PA4-----SAI1_FS_BLPTIM2_OUTEVENTOUT
PA5------LPTIM2_ETREVENTOUT
PA6 LPUART1_CTS - QUADSPI_
BK1_IO3 -TIM1_BKIN_
COMP2 - TIM16_CH1 EVENTOUT
PA7 - - QUADSPI_
BK1_IO2 - COMP2_OUT - - EVENTOUT
PA8 - - - - SWPMI1_IO SAI1_SCK_A LPTIM2_OUT EVENTOUT
PA9-----SAI1_FS_ATIM15_BKINEVENTOUT
PA10 - - USB_CRS_
SYNC - - SAI1_SD_A - EVENTOUT
PA11 - CAN1_RX USB_DM - TIM1_BKIN2_
COMP1 - - EVENTOUT
PA12 - CAN1_TX USB_DP - - - - EVENTOUT
PA13 - - USB_NOE - SWPMI1_TX SAI1_SD_B - EVENTOUT
PA14 - - - - SWPMI1_RX SAI1_FS_B - EVENTOUT
PA15 - TSC_G3_IO1 - - SWPMI1_
SUSPEND - - EVENTOUT
Pinouts and pin description STM32L432KB STM32L432KC
58/156 DS11451 Rev 4
Port B
PB0 - - QUADSPI_
BK1_IO1 - COMP1_OUT SAI1_EXTCLK - EVENTOUT
PB1 LPUART1_RTS
_DE -QUADSPI_
BK1_IO0 - - - LPTIM2_IN1 EVENTOUT
PB3-----SAI1_SCK_B-EVENTOUT
PB4 - TSC_G2_IO1 - - - SAI1_MCLK_B - EVENTOUT
PB5 - TSC_G2_IO2 - - COMP2_OUT SAI1_SD_B TIM16_BKIN EVENTOUT
PB6 - TSC_G2_IO3 - - - SAI1_FS_B TIM16_CH1N EVENTOUT
PB7 - TSC_G2_IO4 - - - - - EVENTOUT
Port C
PC14------ -EVENTOUT
PC15------ -EVENTOUT
Port HPH3------ -EVENTOUT
1. Please refer to Table 15 for AF0 to AF7.
Table 16. Alternate function AF8 to AF15(1) (continued)
Port
AF8 AF9 AF10 AF11 AF12 AF13 AF14 AF15
LPUART1 CAN1/TSC USB/QUADSPI -
COMP1/
COMP2/
SWPMI1
SAI1 TIM2/TIM15/
TIM16/LPTIM2 EVENTOUT
DS11451 Rev 4 59/156
STM32L432KB STM32L432KC Memory mapping
62
5 Memory mapping
Figure 6. STM32L432xx memory map
MSv36892V2
0xFFFF FFFF
0xE000 0000
0xC000 0000
0xA000 1000
0x8000 0000
0x6000 0000
0x4000 0000
0x2000 0000
0x0000 0000
0
1
2
3
4
5
6
7
Cortex™-M4
with FPU
Internal
Peripherals
Peripherals
SRAM1
CODE
OTP area
System memory
Flash memory
Flash, system memory
or SRAM, depending on
BOOT configuration
AHB2
AHB1
APB2
APB1
0x5006 0C00
0x4800 0000
0x4002 4400
0x4002 0000
0x4001 5800
0x4001 0000
0x4000 9800
0x4000 0000
0x1FFF FFFF
0x1FFF 0000
0x0804 0000
0x0800 0000
0x0004 0000
0x0000 0000
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
0x1000 4000
0x1000 0000
SRAM2
QUADSPI
registers
Options Bytes
0x1FFF 7000
0x1FFF 7400
0x1FFF 7800
0x1FFF 7810
Reserved
QUADSPI registers
0xBFFF FFFF
0xA000 1400
0xA000 1000
Reserved
Reserved
Reserved
0x5FFF FFFF
0x9000 0000
QUADSPI Flash
bank
SRAM2
0x2000 C000
0xA000 0000
Memory mapping STM32L432KB STM32L432KC
60/156 DS11451 Rev 4
Table 17. STM32L432xx memory map and peripheral register boundary addresses(1)
Bus Boundary address Size(bytes) Peripheral
AHB2
0x5006 0800 - 0x5006 0BFF 1 KB RNG
0x5004 0400 - 0x5006 07FF 158 KB Reserved
0x5004 0000 - 0x5004 03FF 1 KB ADC
0x5000 0000 - 0x5003 FFFF 16 KB Reserved
0x4800 2000 - 0x4FFF FFFF ~127 MB Reserved
0x4800 1C00 - 0x4800 1FFF 1 KB GPIOH
0x4800 0C00 - 0x4800 1BFF 4 KB Reserved
0x4800 0800 - 0x4800 0BFF 1 KB GPIOC
0x4800 0400 - 0x4800 07FF 1 KB GPIOB
0x4800 0000 - 0x4800 03FF 1 KB GPIOA
-0x4002 4400 - 0x47FF FFFF ~127 MB Reserved
AHB1
0x4002 4000 - 0x4002 43FF 1 KB TSC
0x4002 3400 - 0x4002 3FFF 1 KB Reserved
0x4002 3000 - 0x4002 33FF 1 KB CRC
0x4002 2400 - 0x4002 2FFF 3 KB Reserved
0x4002 2000 - 0x4002 23FF 1 KB FLASH registers
0x4002 1400 - 0x4002 1FFF 3 KB Reserved
0x4002 1000 - 0x4002 13FF 1 KB RCC
0x4002 0800 - 0x4002 0FFF 2 KB Reserved
0x4002 0400 - 0x4002 07FF 1 KB DMA2
0x4002 0000 - 0x4002 03FF 1 KB DMA1
APB2
0x4001 5800 - 0x4001 FFFF 42 KB Reserved
0x4001 5400 - 0x4000 57FF 1 KB SAI1
0x4001 4800 - 0x4000 53FF 3 KB Reserved
0x4001 4400 - 0x4001 47FF 1 KB TIM16
0x4001 4000 - 0x4001 43FF 1 KB TIM15
0x4001 3C00 - 0x4001 3FFF 1 KB Reserved
0x4001 3800 - 0x4001 3BFF 1 KB USART1
0x4001 3400 - 0x4001 37FF 1 KB Reserved
0x4001 3000 - 0x4001 33FF 1 KB SPI1
0x4001 2C00 - 0x4001 2FFF 1 KB TIM1
0x4001 2000 - 0x4001 2BFF 3 KB Reserved
DS11451 Rev 4 61/156
STM32L432KB STM32L432KC Memory mapping
62
APB2
0x4001 1C00 - 0x4001 1FFF 1 KB FIREWALL
0x4001 0800- 0x4001 1BFF 5 KB Reserved
0x4001 0400 - 0x4001 07FF 1 KB EXTI
0x4001 0200 - 0x4001 03FF
1 KB
COMP
0x4001 0030 - 0x4001 01FF Reserved
0x4001 0000 - 0x4001 002F SYSCFG
APB1
0x4000 9800 - 0x4000 FFFF 26 KB Reserved
0x4000 9400 - 0x4000 97FF 1 KB LPTIM2
0x4000 8C00 - 0x4000 93FF 2 KB Reserved
0x4000 8800 - 0x4000 8BFF 1 KB SWPMI1
0x4000 8400 - 0x4000 87FF 1 KB Reserved
0x4000 8000 - 0x4000 83FF 1 KB LPUART1
0x4000 7C00 - 0x4000 7FFF 1 KB LPTIM1
0x4000 7800 - 0x4000 7BFF 1 KB OPAMP
0x4000 7400 - 0x4000 77FF 1 KB DAC1
0x4000 7000 - 0x4000 73FF 1 KB PWR
0x4000 6C00 - 0x4000 6FFF 1 KB USB SRAM
0x4000 6800 - 0x4000 6BFF 1 KB USB FS
0x4000 6400 - 0x4000 67FF 1 KB CAN1
0x4000 6000 - 0x4000 63FF 1 KB CRS
0x4000 5C00- 0x4000 5FFF 1 KB I2C3
0x4000 5800 - 0x4000 5BFF 1 KB Reserved
0x4000 5400 - 0x4000 57FF 1 KB I2C1
0x4000 4800 - 0x4000 53FF 3 KB Reserved
0x4000 4400 - 0x4000 47FF 1 KB USART2
0x4000 4000 - 0x4000 43FF 1 KB Reserved
0x4000 3C00 - 0x4000 3FFF 1 KB SPI3
0x4000 3400 - 0x4000 3BFF 2 KB Reserved
0x4000 3000 - 0x4000 33FF 1 KB IWDG
0x4000 2C00 - 0x4000 2FFF 1 KB WWDG
0x4000 2800 - 0x4000 2BFF 1 KB RTC
0x4000 1800 - 0x4000 27FF 4 KB Reserved
0x4000 1400 - 0x4000 17FF 1 KB TIM7
Table 17. STM32L432xx memory map and peripheral register boundary addresses(1)
(continued)
Bus Boundary address Size(bytes) Peripheral
Memory mapping STM32L432KB STM32L432KC
62/156 DS11451 Rev 4
APB1
0x4000 1000 - 0x4000 13FF 1 KB TIM6
0x4000 0400- 0x4000 0FFF 3 KB Reserved
0x4000 0000 - 0x4000 03FF 1 KB TIM2
1. The gray color is used for reserved boundary addresses.
Table 17. STM32L432xx memory map and peripheral register boundary addresses(1)
(continued)
Bus Boundary address Size(bytes) Peripheral
DS11451 Rev 4 63/156
STM32L432KB STM32L432KC Electrical characteristics
148
6 Electrical characteristics
6.1 Parameter conditions
Unless otherwise specified, all voltages are referenced to VSS.
6.1.1 Minimum and maximum values
Unless otherwise specified, the minimum and maximum values are guaranteed in the worst
conditions of ambient temperature, supply voltage and frequencies by tests in production on
100% of the devices with an ambient temperature at TA = 25 °C and TA = TAmax (given by
the selected temperature range).
Data based on characterization results, design simulation and/or technology characteristics
are indicated in the table footnotes and are not tested in production. Based on
characterization, the minimum and maximum values refer to sample tests and represent the
mean value plus or minus three times the standard deviation (mean ±3).
6.1.2 Typical values
Unless otherwise specified, typical data are based on TA = 25 °C, VDD = VDDA = 3 V. They
are given only as design guidelines and are not tested.
Typical ADC accuracy values are determined by characterization of a batch of samples from
a standard diffusion lot over the full temperature range, where 95% of the devices have an
error less than or equal to the value indicated (mean ±2).
6.1.3 Typical curves
Unless otherwise specified, all typical curves are given only as design guidelines and are
not tested.
6.1.4 Loading capacitor
The loading conditions used for pin parameter measurement are shown in Figure 7.
6.1.5 Pin input voltage
The input voltage measurement on a pin of the device is described in Figure 8.
Figure 7. Pin loading conditions Figure 8. Pin input voltage
MS19210V1
MCU pin
C = 50 pF
MS19211V1
MCU pin
V
IN
Electrical characteristics STM32L432KB STM32L432KC
64/156 DS11451 Rev 4
6.1.6 Power supply scheme
Figure 9. Power supply scheme
Caution: Each power supply pair (VDD/VSS, VDDA/VSSA etc.) must be decoupled with filtering ceramic
capacitors as shown above. These capacitors must be placed as close as possible to, or
below, the appropriate pins on the underside of the PCB to ensure the good functionality of
the device.
MSv40915V2
VDD
Level shifter
IO
logic
Kernel logic
(CPU, Digital
& Memories)
Backup circuitry
(LSE, RTC,
Backup registers)
IN
OUT
Regulator
GPIOs
1.55 – 3.6 V
n x 100 nF
+1 x 4.7 μF
n x VSS
n x VDD
VCORE
VDDIO1
ADCs/
DACs/
OPAMPs/
COMPs
VREF+
VREF-
VDDA
10 nF
+1 μF
VDDA
VSSA
VREF
100 nF +1 μF
DS11451 Rev 4 65/156
STM32L432KB STM32L432KC Electrical characteristics
148
6.1.7 Current consumption measurement
Figure 10. Current consumption measurement scheme
The IDD_ALL parameters given in Table 25 to Table 37 represent the total MCU consumption
including the current supplying VDD, VDDA, VDDUSB and VBAT.
6.2 Absolute maximum ratings
Stresses above the absolute maximum ratings listed in Table 18: Voltage characteristics,
Table 19: Current characteristics and Table 20: Thermal characteristics may cause
permanent damage to the device. These are stress ratings only and functional operation of
the device at these conditions is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability. Device mission profile (application conditions)
is compliant with JEDEC JESD47 qualification standard, extended mission profiles are
available on demand.
Table 18. Voltage characteristics(1)
Symbol Ratings Min Max Unit
VDDX - VSS
External main supply voltage (including
VDD, VDDA, VDDUSB)-0.3 4.0 V
VIN(2)
Input voltage on FT_xxx pins VSS-0.3 min (VDD, VDDA, VDDUSB)
+ 4.0(3)(4)
V
Input voltage on TT_xx pins VSS-0.3 4.0
Input voltage on any other pins VSS-0.3 4.0
|VDDx|Variations between different VDDX power
pins of the same domain -50mV
|VSSx-VSS|Variations between all the different ground
pins(5) -50mV
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1. All main power (VDD, VDDA, VDDUSB,) and ground (VSS, VSSA) pins must always be connected to the external power supply,
in the permitted range.
2. VIN maximum must always be respected. Refer to Table 19: Current characteristics for the maximum allowed injected
current values.
3. This formula has to be applied only on the power supplies related to the IO structure described in the pin definition table.
4. To sustain a voltage higher than 4 V the internal pull-up/pull-down resistors must be disabled.
5. Include VREF- pin.
Table 19. Current characteristics
Symbol Ratings Max Unit
IVDD Total current into sum of all VDD power lines (source)(1) 140
mA
IVSS Total current out of sum of all VSS ground lines (sink)(1) 140
IVDD(PIN) Maximum current into each VDD power pin (source)(1) 100
IVSS(PIN) Maximum current out of each VSS ground pin (sink)(1) 100
IIO(PIN)
Output current sunk by any I/O and control pin except FT_f 20
Output current sunk by any FT_f pin 20
Output current sourced by any I/O and control pin 20
IIO(PIN)
Total output current sunk by sum of all I/Os and control pins(2) 100
Total output current sourced by sum of all I/Os and control pins(2) 100
IINJ(PIN)(3)
Injected current on FT_xxx, TT_xx, RST and B pins, except PA4,
PA5 -5/+0(4)
Injected current on PA4, PA5 -5/0
|IINJ(PIN)|Total injected current (sum of all I/Os and control pins)(5) 25
1. All main power (VDD, VDDA, VDDUSB) and ground (VSS, VSSA) pins must always be connected to the external power
supplies, in the permitted range.
2. This current consumption must be correctly distributed over all I/Os and control pins. The total output current must not be
sunk/sourced between two consecutive power supply pins referring to high pin count QFP packages.
3. Positive injection (when VIN > VDDIOx) is not possible on these I/Os and does not occur for input voltages lower than the
specified maximum value.
4. A negative injection is induced by VIN < VSS. IINJ(PIN) must never be exceeded. Refer also to Table 18: Voltage
characteristics for the maximum allowed input voltage values.
5. When several inputs are submitted to a current injection, the maximum |IINJ(PIN)| is the absolute sum of the negative
injected currents (instantaneous values).
Table 20. Thermal characteristics
Symbol Ratings Value Unit
TSTG Storage temperature range –65 to +150 °C
TJMaximum junction temperature 150 °C
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STM32L432KB STM32L432KC Electrical characteristics
148
6.3 Operating conditions
6.3.1 General operating conditions
Table 21. General operating conditions
Symbol Parameter Conditions Min Max Unit
fHCLK Internal AHB clock frequency - 0 80
MHzfPCLK1 Internal APB1 clock frequency - 0 80
fPCLK2 Internal APB2 clock frequency - 0 80
VDD Standard operating voltage - 1.71
(1) 3.6 V
VDDA Analog supply voltage
ADC or COMP used 1.62
3.6 V
DAC or OPAMP used 1.8
ADC, DAC, OPAMP, COMP not
used 0
VDDUSB USB supply voltage
USB used 3.0 3.6
V
USB not used 0 3.6
VIN I/O input voltage
TT_xx I/O -0.3 VDDIOx+0.3
V
All I/O except TT_xx -0.3
Min(Min(VDD, VDDA,
VDDUSB)+3.6 V,
5.5 V)(2)(3)
PD
Power dissipation at
TA = 125 °C for suffix 3(4) UFQFPN32 - 128 mW
PD
Power dissipation at
TA = 85 °C for suffix 6
or
TA = 105 °C for suffix 7(4)
UFQFPN32 - 523 mW
TA
Ambient temperature for the
suffix 6 version
Maximum power dissipation –40 85
°C
Low-power dissipation(5) –40 105
Ambient temperature for the
suffix 7 version
Maximum power dissipation –40 105
Low-power dissipation(5) –40 125
Ambient temperature for the
suffix 3 version
Maximum power dissipation –40 125
Low-power dissipation(5) –40 130
TJ Junction temperature range
Suffix 6 version –40 105
°CSuffix 7 version –40 125
Suffix 3 version –40 130
1. When RESET is released functionality is guaranteed down to VBOR0 Min.
2. This formula has to be applied only on the power supplies related to the IO structure described by the pin definition table.
Maximum I/O input voltage is the smallest value between Min(VDD, VDDA, VDDUSB)+3.6 V and 5.5V.
3. For operation with voltage higher than Min (VDD, VDDA, VDDUSB) +0.3 V, the internal Pull-up and Pull-Down resistors must
be disabled.
4. If TA is lower, higher PD values are allowed as long as TJ does not exceed TJmax (see Section 7.2: Thermal characteristics).
Electrical characteristics STM32L432KB STM32L432KC
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6.3.2 Operating conditions at power-up / power-down
The parameters given in Table 22 are derived from tests performed under the ambient
temperature condition summarized in Table 21.
The requirements for power-up/down sequence specified in Section 3.9.1: Power supply
schemes must be respected.
6.3.3 Embedded reset and power control block characteristics
The parameters given in Table 23 are derived from tests performed under the ambient
temperature conditions summarized in Table 21: General operating conditions.
5. In low-power dissipation state, TA can be extended to this range as long as TJ does not exceed TJmax (see Section 7.2:
Thermal characteristics).
Table 22. Operating conditions at power-up / power-down
Symbol Parameter Conditions Min Max Unit
tVDD
VDD rise time rate
-
0
µs/V
VDD fall time rate 10
tVDDA
VDDA rise time rate
-
0
VDDA fall time rate 10
tVDDUSB
VDDUSB rise time rate
-
0
VDDUSB fall time rate 10
Table 23. Embedded reset and power control block characteristics
Symbol Parameter Conditions(1) Min Typ Max Unit
tRSTTEMPO(2) Reset temporization after
BOR0 is detected VDD rising - 250 400 s
VBOR0(2) Brown-out reset threshold 0
Rising edge 1.62 1.66 1.7
V
Falling edge 1.6 1.64 1.69
VBOR1 Brown-out reset threshold 1
Rising edge 2.06 2.1 2.14
V
Falling edge 1.96 2 2.04
VBOR2 Brown-out reset threshold 2
Rising edge 2.26 2.31 2.35
V
Falling edge 2.16 2.20 2.24
VBOR3 Brown-out reset threshold 3
Rising edge 2.56 2.61 2.66
V
Falling edge 2.47 2.52 2.57
VBOR4 Brown-out reset threshold 4
Rising edge 2.85 2.90 2.95
V
Falling edge 2.76 2.81 2.86
VPVD0
Programmable voltage
detector threshold 0
Rising edge 2.1 2.15 2.19
V
Falling edge 2 2.05 2.1
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STM32L432KB STM32L432KC Electrical characteristics
148
VPVD1 PVD threshold 1
Rising edge 2.26 2.31 2.36
V
Falling edge 2.15 2.20 2.25
VPVD2 PVD threshold 2
Rising edge 2.41 2.46 2.51
V
Falling edge 2.31 2.36 2.41
VPVD3 PVD threshold 3
Rising edge 2.56 2.61 2.66
V
Falling edge 2.47 2.52 2.57
VPVD4 PVD threshold 4
Rising edge 2.69 2.74 2.79
V
Falling edge 2.59 2.64 2.69
VPVD5 PVD threshold 5
Rising edge 2.85 2.91 2.96
V
Falling edge 2.75 2.81 2.86
VPVD6 PVD threshold 6
Rising edge 2.92 2.98 3.04
V
Falling edge 2.84 2.90 2.96
Vhyst_BORH0 Hysteresis voltage of BORH0
Hysteresis in
continuous
mode
-20-
mV
Hysteresis in
other mode -30-
Vhyst_BOR_PVD
Hysteresis voltage of BORH
(except BORH0) and PVD --100-mV
IDD
(BOR_PVD)(2)
BOR(3) (except BOR0) and
PVD consumption from VDD
--1.11.6µA
VPVM1
VDDUSB peripheral voltage
monitoring - 1.18 1.22 1.26 V
VPVM3
VDDA peripheral voltage
monitoring
Rising edge 1.61 1.65 1.69
V
Falling edge 1.6 1.64 1.68
VPVM4
VDDA peripheral voltage
monitoring
Rising edge 1.78 1.82 1.86
V
Falling edge 1.77 1.81 1.85
Vhyst_PVM3 PVM3 hysteresis - - 10 - mV
Vhyst_PVM4 PVM4 hysteresis - - 10 - mV
IDD (PVM1)
(2) PVM1 consumption from VDD --0.2-µA
IDD
(PVM3/PVM4)
(2)
PVM3 and PVM4
consumption from VDD
--2-µA
1. Continuous mode means Run/Sleep modes, or temperature sensor enable in Low-power run/Low-power
sleep modes.
2. Guaranteed by design.
3. BOR0 is enabled in all modes (except shutdown) and its consumption is therefore included in the supply
current characteristics tables.
Table 23. Embedded reset and power control block characteristics (continued)
Symbol Parameter Conditions(1) Min Typ Max Unit
Electrical characteristics STM32L432KB STM32L432KC
70/156 DS11451 Rev 4
6.3.4 Embedded voltage reference
The parameters given in Table 24 are derived from tests performed under the ambient
temperature and supply voltage conditions summarized in Table 21: General operating
conditions.
Table 24. Embedded internal voltage reference
Symbol Parameter Conditions Min Typ Max Unit
VREFINT Internal reference voltage –40 °C < TA < +130 °C 1.182 1.212 1.232 V
tS_vrefint (1)
ADC sampling time when
reading the internal reference
voltage
-4
(2) --µs
tstart_vrefint
Start time of reference voltage
buffer when ADC is enable --812
(2) µs
IDD(VREFINTBUF)
VREFINT buffer consumption
from VDD when converted by
ADC
- - 12.5 20(2) µA
VREFINT
Internal reference voltage
spread over the temperature
range
VDD = 3 V - 5 7.5(2) mV
TCoeff Temperature coefficient –40°C < TA < +130°C - 30 50(2) ppm/°C
ACoeff Long term stability 1000 hours, T = 25°C - 300 1000(2) ppm
VDDCoeff Voltage coefficient 3.0 V < VDD < 3.6 V - 250 1200(2) ppm/V
VREFINT_DIV1 1/4 reference voltage
-
24 25 26
%
VREFINT
VREFINT_DIV2 1/2 reference voltage 49 50 51
VREFINT_DIV3 3/4 reference voltage 74 75 76
1. The shortest sampling time can be determined in the application by multiple iterations.
2. Guaranteed by design.
DS11451 Rev 4 71/156
STM32L432KB STM32L432KC Electrical characteristics
148
Figure 11. VREFINT versus temperature
MSv40169V1
1.185
1.19
1.195
1.2
1.205
1.21
1.215
1.22
1.225
1.23
1.235
-40 -20 0 20 40 60 80 100 120
V
°C
Mean Min Max
Electrical characteristics STM32L432KB STM32L432KC
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6.3.5 Supply current characteristics
The current consumption is a function of several parameters and factors such as the
operating voltage, ambient temperature, I/O pin loading, device software configuration,
operating frequencies, I/O pin switching rate, program location in memory and executed
binary code.
The current consumption is measured as described in Figure 10: Current consumption
measurement scheme.
Typical and maximum current consumption
The MCU is placed under the following conditions:
All I/O pins are in analog input mode
All peripherals are disabled except when explicitly mentioned
The Flash memory access time is adjusted with the minimum wait states number,
depending on the fHCLK frequency (refer to the table “Number of wait states according
to CPU clock (HCLK) frequency” available in the RM0394 reference manual).
When the peripherals are enabled fPCLK = fHCLK
The parameters given in Table 25 to Table 37 are derived from tests performed under
ambient temperature and supply voltage conditions summarized in Table 21: General
operating conditions.
STM32L432KB STM32L432KC Electrical characteristics
DS11451 Rev 4 73/156
Table 25. Current consumption in Run and Low-power run modes, code with data processing
running from Flash, ART enable (Cache ON Prefetch OFF)
Symbol Parameter
Conditions TYP MAX(1)
Unit
-Voltage
scaling fHCLK 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Run)
Supply
current in
Run mode
fHCLK = fHSE up to
48MHz included,
bypass mode
PLL ON above
48 MHz all
peripherals disable
Range 2
26 MHz 2.37 2.38 2.44 2.52 2.66 2.7 2.7 2.8 2.9 3.2
mA
16 MHz 1.5 1.52 1.57 1.64 1.79 1.7 1.7 1.8 2.0 2.3
8 MHz 0.81 0.82 0.87 0.94 1.08 0.9 0.9 1.0 1.2 1.5
4 MHz 0.46 0.47 0.52 0.59 0.73 0.5 0.6 0.6 0.8 1.1
2 MHz 0.29 0.3 0.34 0.41 0.55 0.3 0.4 0.4 0.6 0.9
1 MHz 0.2 0.21 0.25 0.32 0.46 0.2 0.3 0.3 0.5 0.8
100 kHz 0.12 0.13 0.17 0.24 0.38 0.1 0.2 0.2 0.4 0.7
Range 1
80 MHz 8.53 8.56 8.64 8.74 8.92 9.5 9.6 9.7 9.9 10.3
72 MHz 7.7 7.73 7.8 7.9 8.08 8.6 8.6 8.7 8.9 9.3
64 MHz 6.86 6.9 6.97 7.06 7.23 7.7 7.7 7.8 8.0 8.3
48 MHz 5.13 5.16 5.23 5.32 5.49 5.8 5.8 6.0 6.1 6.5
32 MHz 3.46 3.48 3.55 3.64 3.8 3.9 4.0 4.1 4.2 4.6
24 MHz 2.63 2.64 2.71 2.79 2.96 3.0 3.0 3.1 3.3 3.6
16 MHz 1.8 1.81 1.87 1.96 2.12 2.0 2.1 2.2 2.3 2.7
IDD_ALL
(LPRun)
Supply
current in
Low-power
run mode
fHCLK = fMSI
all peripherals disable
2 MHz 211 230 280 355 506 273.8 301.1 360.4 502.7 815.9
µA
1 MHz 117 134 179 254 404 154.7 184.6 249.6 398.4 712.4
400 kHz 58.5 70.4 116 189 338 80.2 111.5 179.7 330.8 643.4
100 kHz 30 41.1 85.2 159 308 46.5 76.6 147.1 299.1 611.2
1. Guaranteed by characterization results, unless otherwise specified.
Electrical characteristics STM32L432KB STM32L432KC
74/156 DS11451 Rev 4
Table 26. Current consumption in Run and Low-power run modes, code with data processing
running from Flash, ART disable
Symbol Parameter
Conditions TYP MAX(1)
Unit
-Voltage
scaling fHCLK 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Run)
Supply
current in
Run mode
fHCLK = fHSE up to
48MHz included,
bypass mode
PLL ON above
48 MHz all
peripherals disable
Range 2
26 MHz 2.66 2.68 2.73 2.81 2.96 3.0 3.1 3.2 3.3 3.6
mA
16 MHz 1.88 1.9 1.94 2.02 2.17 2.1 2.2 2.3 2.4 2.7
8 MHz 1.05 1.06 1.11 1.18 1.33 1.2 1.2 1.3 1.4 1.7
4 MHz 0.6 0.62 0.66 0.73 0.87 0.7 0.7 0.8 0.9 1.2
2 MHz 0.36 0.37 0.34 0.48 0.62 0.4 0.4 0.5 0.6 0.9
1 MHz 0.23 0.25 0.25 0.36 0.5 0.3 0.3 0.4 0.5 0.8
100 kHz 0.12 0.14 0.17 0.25 0.39 0.1 0.2 0.2 0.4 0.7
Range 1
80 MHz 8.56 8.61 8.69 8.79 8.97 9.6 9.7 9.8 10.0 10.3
72 MHz 7.74 7.79 7.86 7.96 8.14 8.7 8.7 8.8 9.0 9.4
64 MHz 7.63 7.68 7.75 7.85 8.04 8.6 8.6 8.7 8.9 9.3
48 MHz 6.36 6.4 6.48 6.58 6.76 7.2 7.3 7.4 7.6 7.9
32 MHz 4.56 4.6 4.66 4.76 4.93 5.2 5.2 5.3 5.5 5.8
24 MHz 3.45 3.48 3.54 3.64 3.8 3.9 4.0 4.1 4.2 4.6
16 MHz 2.48 2.51 2.56 2.65 2.82 2.8 2.9 3.0 3.1 3.5
IDD_ALL
(LPRun)
Supply
current in
Low-power
run
fHCLK = fMSI
all peripherals disable
2 MHz 310 317 364 440 593 375.3 400.9 456.7 595.3 909.6
µA
1 MHz 157 173 226 296 448 204.8 234.2 298.2 445.8 758.9
400 kHz 72.6 89 130 206 356 99.7 131.2 199.7 349.3 663.7
100 kHz 32.3 46 89.7 164 314 52.4 82.1 153.3 301.2 616.9
1. Guaranteed by characterization results, unless otherwise specified.
STM32L432KB STM32L432KC Electrical characteristics
DS11451 Rev 4 75/156
Table 27. Current consumption in Run and Low-power run modes, code with data processing
running from SRAM1
Symbol Parameter
Conditions TYP MAX(1)
Unit
-Voltage
scaling fHCLK 25 °C 55 °C 85 °C 105
°C
125
°C 25 °C 55 °C 85 °C 105
°C
125
°C
IDD_ALL
(Run)
Supply
current in
Run mode
fHCLK = fHSE up to
48MHz included,
bypass mode
PLL ON above
48 MHz all
peripherals disable
Range 2
26 MHz 2.42 2.43 2.49 2.56 2.71 2.7 2.7 2.8 3.0 3.3
mA
16 MHz 1.54 1.55 1.6 1.67 1.82 1.7 1.7 1.8 2.0 2.3
8 MHz 0.82 0.84 0.88 0.95 1.1 0.9 1.0 1.0 1.2 1.5
4 MHz 0.47 0.48 0.52 0.59 0.73 0.5 0.6 0.6 0.8 1.1
2 MHz 0.29 0.3 0.34 0.41 0.55 0.3 0.4 0.4 0.6 0.9
1 MHz 0.2 0.21 0.25 0.32 0.46 0.2 0.3 0.3 0.5 0.8
100 kHz 0.12 0.13 0.17 0.24 0.38 0.1 0.2 0.2 0.4 0.7
Range 1
80 MHz 8.63 8.68 8.74 8.84 9.01 9.5 9.6 9.7 9.9 10.2
72 MHz 7.79 7.83 7.9 7.99 8.17 8.6 8.6 8.8 8.9 9.3
64 MHz 6.95 6.99 7.05 7.15 7.32 7.7 7.7 7.9 8.0 8.4
48 MHz 5.19 5.22 5.29 5.38 5.55 5.8 5.8 5.9 6.1 6.5
32 MHz 3.51 3.53 3.6 3.68 3.85 3.9 4.0 4.1 4.2 4.6
24 MHz 2.66 2.68 2.74 2.83 2.99 3.0 3.0 3.1 3.3 3.6
16 MHz 1.82 1.84 1.89 1.98 2.14 2.0 2.1 2.2 2.3 2.7
IDD_ALL
(LPRun)
Supply
current in
low-power
run mode
fHCLK = fMSI
all peripherals disable
FLASH in power-down
2 MHz 205 228 275 352 501 276.5 302.3 358.4 502.5 816.4
µA
1 MHz 111 126 175 248 397 151.3 180.9 245.3 390.7 703.4
400 kHz 49.2 62.7 108 181 330 73.3 104.0 170.8 321.0 632.4
100 kHz 21.5 33.3 76.6 151 299 36.4 67.7 137.2 287.8 600.8
1. Guaranteed by characterization results, unless otherwise specified.
Electrical characteristics STM32L432KB STM32L432KC
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Table 28. Typical current consumption in Run and Low-power run modes, with different codes
running from Flash, ART enable (Cache ON Prefetch OFF)
Symbol Parameter
Conditions TYP
Unit
TYP
Unit
-Voltage
scaling Code 25 °C 25 °C
IDD_ALL
(Run)
Supply
current in
Run mode
fHCLK = fHSE up
to 48 MHz
included, bypass
mode PLL ON
above 48 MHz
all peripherals
disable
Range 2
fHCLK = 26 MHz
Reduced code(1) 2.37
mA
91
µA/MHz
Coremark 2.69 103
Dhrystone 2.1 2.74 105
Fibonacci 2.58 99
While(1) 2.30 88
Range 1
fHCLK = 80 MHz
Reduced code(1) 8.53
mA
107
µA/MHz
Coremark 9.68 121
Dhrystone 2.1 9.76 122
Fibonacci 9.27 116
While(1) 8.20 103
IDD_ALL
(LPRun)
Supply
current in
Low-power
run
fHCLK = fMSI = 2 MHz
all peripherals disable
Reduced code(1) 211
µA
106
µA/MHz
Coremark 251 126
Dhrystone 2.1 269 135
Fibonacci 230 115
While(1) 286 143
1. Reduced code used for characterization results provided in Table 25, Table 26, Table 27.
DS11451 Rev 4 77/156
STM32L432KB STM32L432KC Electrical characteristics
148
Table 29. Typical current consumption in Run and Low-power run modes, with different codes
running from Flash, ART disable
Symbol Parameter
Conditions TYP
Unit
TYP
Unit
-Voltage
scaling Code 25 °C 25 °C
IDD_ALL
(Run)
Supply
current in
Run mode
fHCLK = fHSE up to
48 MHz included,
bypass mode
PLL ON above
48 MHz
all peripherals
disable
Range 2
fHCLK = 26 MHz
Reduced code(1) 2.66
mA
102
µA/MHz
Coremark 2.44 94
Dhrystone 2.1 2.46 95
Fibonacci 2.27 87
While(1) 2.20 84.6
Range 1
fHCLK = 80 MHz
Reduced code(1) 8.56
mA
107
µA/MHz
Coremark 8.00 100
Dhrystone 2.1 7.98 100
Fibonacci 7.41 93
While(1) 7.83 98
IDD_ALL
(LPRun)
Supply
current in
Low-power
run
fHCLK = fMSI = 2 MHz
all peripherals disable
Reduced code(1) 310
µA
155
µA/MHz
Coremark 342 171
Dhrystone 2.1 324 162
Fibonacci 324 162
While(1) 384 192
1. Reduced code used for characterization results provided in Table 25, Table 26, Table 27.
Table 30. Typical current consumption in Run and Low-power run modes, with different codes
running from SRAM1
Symbol Parameter
Conditions TYP
Unit
TYP
Unit
-Voltage
scaling Code 25 °C 25 °C
IDD_ALL
(Run)
Supply
current in
Run mode
fHCLK = fHSE up to
48 MHz included,
bypass mode
PLL ON above
48 MHz all
peripherals
disable
Range 2
fHCLK = 26 MHz
Reduced code(1) 2.42
mA
93
µA/MHz
Coremark 2.18 84
Dhrystone 2.1 2.40 92
Fibonacci 2.40 92
While(1) 2.29 88
Range 1
fHCLK = 80 MHz
Reduced code(1) 8.63
mA
108
µA/MHz
Coremark 7.76 97
Dhrystone 2.1 8.55 107
Fibonacci 8.56 107
While(1) 8.12 102
IDD_ALL
(LPRun)
Supply
current in
Low-power
run
fHCLK = fMSI = 2 MHz
all peripherals disable
Reduced code(1) 205
µA
103
µA/MHz
Coremark 188 94
Dhrystone 2.1 222 111
Fibonacci 204 102
While(1) 211 106
1. Reduced code used for characterization results provided in Table 25, Table 26, Table 27.
Electrical characteristics STM32L432KB STM32L432KC
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Table 31. Current consumption in Sleep and Low-power sleep modes, Flash ON
Symbol Parameter
Conditions TYP MAX(1)
Unit
-Voltage
scaling fHCLK 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Sleep)
Supply
current in
sleep
mode,
fHCLK = fHSE up
to 48 MHz
included, bypass
mode
pll ON above
48 MHz all
peripherals
disable
Range 2
26 MHz 0.68 0.69 0.74 0.81 0.95 0.8 0.8 0.9 1.0 1.3
mA
16 MHz 0.46 0.48 0.52 0.59 0.73 0.5 0.6 0.6 0.8 1.1
8 MHz 0.29 0.30 0.34 0.41 0.55 0.3 0.4 0.4 0.6 0.9
4 MHz 0.20 0.21 0.25 0.32 0.46 0.2 0.3 0.3 0.5 0.8
2 MHz 0.16 0.17 0.21 0.28 0.42 0.2 0.2 0.3 0.4 0.7
1 MHz 0.13 0.15 0.19 0.26 0.40 0.1 0.2 0.3 0.4 0.7
100 kHz 0.11 0.13 0.17 0.24 0.38 0.1 0.2 0.2 0.4 0.7
Range 1
80 MHz 2.23 2.25 2.30 2.38 2.54 2.5 2.5 2.6 2.8 3.1
72 MHz 2.02 2.04 2.10 2.18 2.34 2.2 2.3 2.4 2.5 2.9
64 MHz 1.82 1.84 1.89 1.98 2.14 2.0 2.1 2.1 2.3 2.6
48 MHz 1.34 1.36 1.42 1.50 1.66 1.5 1.6 1.7 1.8 2.2
32 MHz 0.93 0.95 1.01 1.09 1.25 1.1 1.1 1.2 1.4 1.7
24 MHz 0.73 0.75 0.80 0.88 1.04 0.8 0.9 1.0 1.1 1.4
16 MHz 0.53 0.55 0.60 0.68 0.84 0.6 0.6 0.7 0.9 1.2
IDD_ALL
(LPSleep)
Supply
current in
low-power
sleep
mode
fHCLK = fMSI
all peripherals disable
2 MHz 71.8 80.7 125 200 350 91.1 122.7 191.3 341.5 653.5
µA
1 MHz 45.0 57.3 101 176 325 63.2 95.4 165.4 316.5 628.7
400 kHz 27.0 40.7 84.6 158 308 43.9 75.8 147.2 297.6 609.2
100 kHz 22.8 30.9 63.3 113.2 207.7 35.2 67.9 140.9 290.8 602.4
1. Guaranteed by characterization results, unless otherwise specified.
STM32L432KB STM32L432KC Electrical characteristics
DS11451 Rev 4 79/156
Table 32. Current consumption in Low-power sleep modes, Flash in power-down
Symbol Parameter
Conditions TYP MAX(1)
Unit
-Voltage
scaling fHCLK 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(LPSleep)
Supply current
in low-power
sleep mode
fHCLK = fMSI
all peripherals disable
2 MHz 58.7 70.7 103.2 153.7 248.5 80 113 180 330 641
µA
1 MHz 39.4 47.2 79.3 129.6 224.8 53 86 154 304 616
400 kHz 20.8 30.8 62.1 112.5 207.8 35 67 137 286 597
100 kHz 14.3 23.1 55.1 105.7 201.5 27 58 130 279 590
1. Guaranteed by characterization results, unless otherwise specified.
Table 33. Current consumption in Stop 2 mode
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Stop 2)
Supply current in
Stop 2 mode,
RTC disabled
-
1.8 V 1 2.54 8.74 19.8 43.4 2.0 5.6 21.1 50.8 116.0
µA
2.4 V 1.02 2.59 8.89 20.2 44.3 2.1 5.8 21.6 52.3 119.6
3 V 1.06 2.67 9.11 20.7 45.5 2.1 5.9 22.2 53.7 123.2
3.6 V 1.23 2.88 9.56 21.6 47.3 2.3 6.1 23.0 55.8 127.9
IDD_ALL
(Stop 2 with
RTC)
Supply current in
Stop 2 mode,
RTC enabled
RTC clocked by LSI
1.8 V 1.3 2.82 9.02 20.1 43.6 2.5 6.2 21.6 51.3 116.3
µA
2.4 V 1.39 2.95 9.24 20.5 44.6 2.8 6.4 22.3 52.8 120.0
3 V 1.5 3.11 9.55 21.1 45.8 3.0 6.8 23.0 54.5 123.8
3.6 V 1.76 3.42 10.1 22.1 47.8 3.3 7.2 24.1 56.7 128.7
RTC clocked by LSE
bypassed at 32768 Hz
1.8 V 1.36 2.9 9.1 20.1 43.7 - - - - -
2.4 V 1.48 3.09 9.44 20.8 45 - - - - -
3 V 1.83 3.67 10.4 22.3 47.3 - - - - -
3.6 V 3.58 6.17 13.9 26.6 53 - - - - -
RTC clocked by LSE
quartz(2)
in low drive mode
1.8 V 1.28 2.81 9.13 20.8 - - - - - -
2.4 V 1.39 2.93 9.34 21.3 - - - - - -
3 V 1.59 3.1 9.64 21.8 - - - - - -
3.6 V 1.86 3.45 10.2 22.8 - - - - - -
Electrical characteristics STM32L432KB STM32L432KC
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IDD_ALL
(wakeup from
Stop2)
Supply current
during wakeup
from Stop 2
mode
Wakeup clock is
MSI = 48 MHz,
voltage Range 1.
See (3).
3 V1.85---------
mA
Wakeup clock is
MSI = 4 MHz,
voltage Range 2.
See (3).
3 V1.52---------
Wakeup clock is
HSI16 = 16 MHz,
voltage Range 1.
See (3).
3 V1.54---------
1. Guaranteed based on test during characterization, unless otherwise specified.
2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors.
3. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 39: Low-power mode wakeup timings.
Table 33. Current consumption in Stop 2 mode (continued)
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
STM32L432KB STM32L432KC Electrical characteristics
DS11451 Rev 4 81/156
Table 34. Current consumption in Stop 1 mode
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Stop 1)
Supply
current in
Stop 1 mode,
RTC disabled
-
1.8 V 4.34 12.4 43.6 96.4 204 9.3 27.4 98.9 198.7 397.5
µA
2.4 V 4.35 12.5 43.8 97 205 9.4 27.6 99.5 199.0 398.0
3 V 4.41 12.6 44.1 97.7 207 9.5 27.8 100.3 200.4 400.8
3.6 V 4.56 12.9 44.8 98.9 210 9.7 28.3 101.7 202.1 404.2
IDD_ALL
(Stop 1 with
RTC)
Supply
current in stop
1 mode,
RTC enabled
RTC clocked by LSI
1.8 V 4.63 12.7 43.9 96.8 205 9.9 28.0 99.5 198.9 397.8
µA
2.4 V 4.78 12.8 44.2 97.4 206 10.1 28.3 100.3 199.5 399.0
3 V 4.93 13 44.6 98.1 207 10.4 28.7 101.2 200.9 401.9
3.6 V 5.05 13.4 45.3 99.5 210 10.8 29.4 102.8 202.5 405.0
RTC clocked by LSE
bypassed, at 32768 Hz
1.8 V 4.7 12.8 44 96.9 205 - - - - -
2.4 V 4.95 13 44.4 97.6 206 - - - - -
3 V 5.33 13.6 45.4 99.1 209 - - - - -
3.6 V 6.91 16.1 48.8 103 216 - - - - -
RTC clocked by LSE quartz(2)
in low drive mode
1.8 V 4.76 12.3 43.7 99.1 - - - - - -
2.4 V 4.95 12.4 43.8 99.3 - - - - - -
3 V 5.1 12.6 44.1 99.6 - - - - - -
3.6 V 5.65 13 44.8 101 - - - - - -
IDD_ALL
(wakeup
from Stop1)
Supply
current during
wakeup from
Stop 1
Wakeup clock MSI = 48 MHz,
voltage Range 1.
See (3).
3 V1.14---------
mA
Wakeup clock MSI = 4 MHz,
voltage Range 2.
See (3).
3 V1.22---------
Wakeup clock HSI16 =
16 MHz, voltage Range 1.
See (3).
3 V1.20---------
1. Guaranteed based on test during characterization, unless otherwise specified.
2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors.
3. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 39: Low-power mode wakeup timings.
Electrical characteristics STM32L432KB STM32L432KC
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Table 35. Current consumption in Stop 0
Symbol Parameter
Conditions TYP MAX(1)
1. Guaranteed by characterization results, unless otherwise specified.
Unit
VDD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Stop 0)
Supply
current in
Stop 0 mode,
RTC disabled
1.8 V 108 119 158 221 347 133 158 244 395 704
µA
2.4 V 110 121 160 223 349 136 161 248 399 710
3 V 111 123 161 224 352 139 164 251 403 716
3.6 V 114 125 163 227 355 142 167 254 408 722(2)
2. Guaranteed by test in production.
STM32L432KB STM32L432KC Electrical characteristics
DS11451 Rev 4 83/156
Table 36. Current consumption in Standby mode
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Standby)
Supply current
in Standby
mode (backup
registers
retained),
RTC disabled
no independent watchdog
1.8 V 27.7 144 758 2 072 5 425 119 425 2866 7524 20510
nA
2.4 V 50.9 187 892 2 408 6 247 183 564 3383 8778 23768
3 V 90.2 253 1 090 2 884 7 409 225 681 3912 10071 26976
3.6 V 253 459 1 474 3 575 8 836 292 877 4638 11659 30758
with independent
watchdog
1.8 V 216 - - - - - - - - -
2.4 V 342 - - - - - - - - -
3 V 416 - - - - - - - - -
3.6 V 551 - - - - - - - - -
IDD_ALL
(Standby
with RTC)
Supply current
in Standby
mode (backup
registers
retained),
RTC enabled
RTC clocked by LSI, no
independent watchdog
1.8 V 287 407 989 2 230 5 396 585 944 3344 7866 20504
nA
2.4 V 386 526 1 201 2 638 6 274 811 1230 4007 9246 23824
3 V 513 679 1 478 3 167 7 414 1022 1521 4683 10671 27124
3.6 V 771 978 1 963 3 992 9 039 1284 1924 5577 12383 30954
(2)
RTC clocked by LSI, with
independent watchdog
1.8 V 342 - - - - - - - - -
2.4 V 521 - - - - - - - - -
3 V 655 - - - - - - - - -
3.6 V 865 - - - - - - - - -
RTC clocked by LSE
bypassed at 32768Hz
1.8 V 142 126 865 2 220 5 650 - - - - -
nA
2.4 V 249 219 1 090 2 660 6 600 - - - - -
3 V 404 364 1 410 3 260 7 850 - - - - -
3.6 V 742 670 2 000 4 230 9 700 - - - - -
RTC clocked by LSE
quartz (3) in low drive mode
1.8 V 281 423 1 046 2 410 5 700 - - - - -
2.4 V 388 548 1 268 2 847 6 564 - - - - -
3 V 535 715 1 565 3 420 7 694 - - - - -
3.6 V 836 1 048 2 081 4 311 9 338 - - - - -
Electrical characteristics STM32L432KB STM32L432KC
84/156 DS11451 Rev 4
IDD_ALL
(SRAM2)(4)
Supply current
to be added in
Standby mode
when SRAM2
is retained
-
1.8 V 173 349 1 009 2 158 4 542 249 527 1604 3402 6908
nA
2.4 V 174 345 1 015 2 163 4 535 271 589 1623 3438 6924
3 V 178 350 1 019 2 148 4 419 277 594 1628 3467 6935
3.6 V 184 352 1 033 2 208 4 610 293 611 1631 3480 6948
IDD_ALL
(wakeup
from
Standby)
Supply current
during wakeup
from Standby
mode
Wakeup clock is
MSI = 4 MHz.
See (5).
3 V1.23---------mA
1. Guaranteed by characterization results, unless otherwise specified.
2. Guaranteed by test in production.
3. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors.
4. The supply current in Standby with SRAM2 mode is: IDD_ALL(Standby) + IDD_ALL(SRAM2). The supply current in Standby with RTC with SRAM2 mode is: IDD_ALL(Standby
+ RTC) + IDD_ALL(SRAM2).
5. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 39: Low-power mode wakeup timings.
Table 36. Current consumption in Standby mode (continued)
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
Table 37. Current consumption in Shutdown mode
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
IDD_ALL
(Shutdown)
Supply current
in Shutdown
mode
(backup
registers
retained) RTC
disabled
-
1.8 V 7.82 190 386 1 286 3 854 25.0 255 1721 5052 15543
nA
2.4 V 23 229 485 1 517 4 431 34.9 270 2085 5878 17639
3 V 44.3 290 634 1 878 5 310 70.1 345 2454 6755 19984
3.6 V 212 397 977 2 516 6 656 119.1 496 2992 7939 22860
STM32L432KB STM32L432KC Electrical characteristics
DS11451 Rev 4 85/156
IDD_ALL
(Shutdown
with RTC)
Supply current
in Shutdown
mode
(backup
registers
retained) RTC
enabled
RTC clocked by LSE
bypassed at 32768 Hz
1.8 V 63 133 522 1 490 4 270 - - - - -
nA
2.4 V 165 253 710 1 830 4 980 - - - - -
3 V 316 423 990 2 340 6 050 - - - - -
3.6 V 649 787 1 530 3 220 7 710 - - - - -
RTC clocked by LSE
quartz (2) in low drive
mode
1.8 V 203 293 700 1 675 - - - - - -
2.4 V 303 411 880 2 001 - - - - - -
3 V 448 567 1 136 2 479 - - - - - -
3.6 V 744 887 1 609 3 256 - - - - - -
IDD_ALL
(wakeup from
Shutdown)
Supply current
during wakeup
from Shutdown
mode
Wakeup clock is
MSI = 4 MHz.
See (3).
3 V 0.780 - - - - - - - - - mA
1. Guaranteed by characterization results, unless otherwise specified.
2. Based on characterization done with a 32.768 kHz crystal (MC306-G-06Q-32.768, manufacturer JFVNY) with two 6.8 pF loading capacitors.
3. Wakeup with code execution from Flash. Average value given for a typical wakeup time as specified in Table 39: Low-power mode wakeup timings.
Table 37. Current consumption in Shutdown mode (continued)
Symbol Parameter
Conditions TYP MAX(1)
Unit
-V
DD 25 °C 55 °C 85 °C 105 °C 125 °C 25 °C 55 °C 85 °C 105 °C 125 °C
Electrical characteristics STM32L432KB STM32L432KC
86/156 DS11451 Rev 4
I/O system current consumption
The current consumption of the I/O system has two components: static and dynamic.
I/O static current consumption
All the I/Os used as inputs with pull-up generate current consumption when the pin is
externally held low. The value of this current consumption can be simply computed by using
the pull-up/pull-down resistors values given in Table 57: I/O static characteristics.
For the output pins, any external pull-down or external load must also be considered to
estimate the current consumption.
Additional I/O current consumption is due to I/Os configured as inputs if an intermediate
voltage level is externally applied. This current consumption is caused by the input Schmitt
trigger circuits used to discriminate the input value. Unless this specific configuration is
required by the application, this supply current consumption can be avoided by configuring
these I/Os in analog mode. This is notably the case of ADC input pins which should be
configured as analog inputs.
Caution: Any floating input pin can also settle to an intermediate voltage level or switch inadvertently,
as a result of external electromagnetic noise. To avoid current consumption related to
floating pins, they must either be configured in analog mode, or forced internally to a definite
digital value. This can be done either by using pull-up/down resistors or by configuring the
pins in output mode.
I/O dynamic current consumption
In addition to the internal peripheral current consumption measured previously (see
Table 38: Peripheral current consumption), the I/Os used by an application also contribute
to the current consumption. When an I/O pin switches, it uses the current from the I/O
supply voltage to supply the I/O pin circuitry and to charge/discharge the capacitive load
(internal or external) connected to the pin:
where
ISW is the current sunk by a switching I/O to charge/discharge the capacitive load
VDDIOx is the I/O supply voltage
fSW is the I/O switching frequency
C is the total capacitance seen by the I/O pin: C = CINT+ CEXT + CS
CS is the PCB board capacitance including the pad pin.
The test pin is configured in push-pull output mode and is toggled by software at a fixed
frequency.
ISW VDDIOx fSW C××=
DS11451 Rev 4 87/156
STM32L432KB STM32L432KC Electrical characteristics
148
On-chip peripheral current consumption
The current consumption of the on-chip peripherals is given in Table 38. The MCU is placed
under the following conditions:
All I/O pins are in Analog mode
The given value is calculated by measuring the difference of the current consumptions:
when the peripheral is clocked on
when the peripheral is clocked off
Ambient operating temperature and supply voltage conditions summarized in Table 18:
Voltage characteristics
The power consumption of the digital part of the on-chip peripherals is given in
Table 38. The power consumption of the analog part of the peripherals (where
applicable) is indicated in each related section of the datasheet.
Table 38. Peripheral current consumption
Peripheral Range 1 Range 2 Low-power run
and sleep Unit
AHB
Bus Matrix(1) 3.2 2.9 3.1
µA/MHz
ADC independent clock domain 0.4 0.1 0.2
ADC clock domain 2.1 1.9 1.9
CRC 0.4 0.2 0.3
DMA1 1.4 1.3 1.4
DMA2 1.5 1.3 1.4
FLASH 6.2 5.2 5.8
GPIOA(2) 1.7 1.4 1.6
GPIOB(2)) 1.6 1.3 1.6
GPIOC(2) 1.7 1.5 1.6
GPIOH(2) 0.6 0.6 0.5
QSPI 7.0 5.8 7.3
RNG independent clock domain 2.2 N/A N/A
RNG clock domain 0.5 N/A N/A
SRAM1 0.8 0.9 0.7
SRAM2 1.0 0.8 0.8
TSC 1.6 1.3 1.3
All AHB Peripherals 21.7 18.5 20.3
APB1
AHB to APB1 bridge(3) 0.9 0.7 0.9
CAN1 4.1 3.2 3.9
DAC1 2.4 1.8 2.2
RTCA 1.7 1.1 2.1
CRS 0.3 0.3 0.6
Electrical characteristics STM32L432KB STM32L432KC
88/156 DS11451 Rev 4
APB1
USB FS independent clock
domain 2.9 N/A N/A
µA/MHz
USB FS clock domain 2.3 N/A N/A
I2C1 independent clock domain 3.5 2.8 3.4
I2C1 clock domain 1.1 0.9 1.0
I2C3 independent clock domain 2.9 2.3 2.5
I2C3 clock domain 0.9 0.4 0.8
LPUART1 independent clock
domain 1.9 1.6 1.8
LPUART1 clock domain 0.6 0.6 0.6
LPTIM1 independent clock
domain 2.9 2.4 2.8
LPTIM1 clock domain 0.8 0.4 0.7
LPTIM2 independent clock
domain 3.1 2.7 3.9
LPTIM2 clock domain 0.8 0.7 0.8
OPAMP 0.4 0.2 0.4
PWR 0.4 0.1 0.4
SPI3 1.7 1.3 1.6
SWPMI1 independent clock
domain 1.9 1.6 1.9
SWPMI1 clock domain 0.9 0.7 0.8
TIM2 6.2 5.0 5.9
TIM6 1.0 0.6 0.9
TIM7 1.0 0.6 0.6
USART2 independent clock
domain 4.1 3.6 3.8
USART2 clock domain 1.3 0.9 1.1
WWDG 0.5 0.5 0.5
All APB1 on 40.2 26.7 37.9
APB2
AHB to APB2(4) 1.0 0.9 0.9
FW 0.2 0.2 0.2
SAI1 independent clock domain 2.3 1.8 1.9
SAI1 clock domain 2.1 1.8 2.0
SPI1 1.8 1.6 1.7
SYSCFG/COMP 0.6 0.5 0.6
Table 38. Peripheral current consumption (continued)
Peripheral Range 1 Range 2 Low-power run
and sleep Unit
DS11451 Rev 4 89/156
STM32L432KB STM32L432KC Electrical characteristics
148
6.3.6 Wakeup time from low-power modes and voltage scaling
transition times
The wakeup times given in Table 39 are the latency between the event and the execution of
the first user instruction.
The device goes in low-power mode after the WFE (Wait For Event) instruction.
APB2
TIM1 8.1 6.5 7.6
µA/MHz
TIM15 3.7 3.0 3.4
TIM16 2.7 2.1 2.6
USART1 independent clock
domain 4.8 4.2 4.6
USART1 clock domain 1.5 1.3 1.7
All APB2 on 24.2 19.9 22.6
ALL 86.1 65.1 80.9
1. The BusMatrix is automatically active when at least one master is ON (CPU, DMA).
2. The GPIOx (x= A…H) dynamic current consumption is approximately divided by a factor two versus this table values when
the GPIO port is locked thanks to LCKK and LCKy bits in the GPIOx_LCKR register. In order to save the full GPIOx current
consumption, the GPIOx clock should be disabled in the RCC when all port I/Os are used in alternate function or analog
mode (clock is only required to read or write into GPIO registers, and is not used in AF or analog modes).
3. The AHB to APB1 Bridge is automatically active when at least one peripheral is ON on the APB1.
4. The AHB to APB2 Bridge is automatically active when at least one peripheral is ON on the APB2.
Table 38. Peripheral current consumption (continued)
Peripheral Range 1 Range 2 Low-power run
and sleep Unit
Table 39. Low-power mode wakeup timings(1)
Symbol Parameter Conditions Typ Max Unit
tWUSLEEP
Wakeup time from Sleep
mode to Run mode -66
Nb of
CPU
cycles
tWULPSLEEP
Wakeup time from Low-
power sleep mode to Low-
power run mode
Wakeup in Flash with Flash in power-down
during low-power sleep mode (SLEEP_PD=1 in
FLASH_ACR) and with clock MSI = 2 MHz
68.3
Electrical characteristics STM32L432KB STM32L432KC
90/156 DS11451 Rev 4
tWUSTOP0
Wake up time from Stop 0
mode to Run mode in
Flash
Range 1
Wakeup clock MSI = 48 MHz 3.8 5.7
µs
Wakeup clock HSI16 = 16 MHz 4.1 6.9
Range 2
Wakeup clock MSI = 24 MHz 4.07 6.2
Wakeup clock HSI16 = 16 MHz 4.1 6.8
Wakeup clock MSI = 4 MHz 8.45 11.8
Wake up time from Stop 0
mode to Run mode in
SRAM1
Range 1
Wakeup clock MSI = 48 MHz 1.5 2.9
Wakeup clock HSI16 = 16 MHz 2.4 2.76
Range 2
Wakeup clock MSI = 24 MHz 2.4 3.48
Wakeup clock HSI16 = 16 MHz 2.4 2.76
Wakeup clock MSI = 4 MHz 8.16 10.94
tWUSTOP1
Wake up time from Stop 1
mode to Run in Flash
Range 1
Wakeup clock MSI = 48 MHz 6.34 7.86
µs
Wakeup clock HSI16 = 16 MHz 6.84 8.23
Range 2
Wakeup clock MSI = 24 MHz 6.74 8.1
Wakeup clock HSI16 = 16 MHz 6.89 8.21
Wakeup clock MSI = 4 MHz 10.47 12.1
Wake up time from Stop 1
mode to Run mode in
SRAM1
Range 1
Wakeup clock MSI = 48 MHz 4.7 5.97
Wakeup clock HSI16 = 16 MHz 5.9 6.92
Range 2
Wakeup clock MSI = 24 MHz 5.4 6.51
Wakeup clock HSI16 = 16 MHz 5.9 6.92
Wakeup clock MSI = 4 MHz 11.1 12.2
Wake up time from Stop 1
mode to Low-power run
mode in Flash Regulator in
low-power
mode (LPR=1
in PWR_CR1)
Wakeup clock MSI = 2 MHz
16.4 17.73
Wake up time from Stop 1
mode to Low-power run
mode in SRAM1
17.3 18.82
Table 39. Low-power mode wakeup timings(1) (continued)
Symbol Parameter Conditions Typ Max Unit
DS11451 Rev 4 91/156
STM32L432KB STM32L432KC Electrical characteristics
148
tWUSTOP2
Wake up time from Stop 2
mode to Run mode in
Flash
Range 1
Wakeup clock MSI = 48 MHz 8.02 9.24
µs
Wakeup clock HSI16 = 16 MHz 7.66 8.95
Range 2
Wakeup clock MSI = 24 MHz 8.5 9.54
Wakeup clock HSI16 = 16 MHz 7.75 8.95
Wakeup clock MSI = 4 MHz 12.06 13.16
Wake up time from Stop 2
mode to Run mode in
SRAM1
Range 1
Wakeup clock MSI = 48 MHz 5.45 6.79
Wakeup clock HSI16 = 16 MHz 6.9 7.98
Range 2
Wakeup clock MSI = 24 MHz 6.3 7.36
Wakeup clock HSI16 = 16 MHz 6.9 7.9
Wakeup clock MSI = 4 MHz 13.1 13.31
tWUSTBY
Wakeup time from Standby
mode to Run mode Range 1
Wakeup clock MSI = 8 MHz 12.2 18.35
µs
Wakeup clock MSI = 4 MHz 19.14 25.8
tWUSTBY
SRAM2
Wakeup time from Standby
with SRAM2 to Run mode Range 1
Wakeup clock MSI = 8 MHz 12.1 18.3
µs
Wakeup clock MSI = 4 MHz 19.2 25.87
tWUSHDN
Wakeup time from
Shutdown mode to Run
mode
Range 1 Wakeup clock MSI = 4 MHz 261.5 315.7 µs
1. Guaranteed by characterization results.
Table 39. Low-power mode wakeup timings(1) (continued)
Symbol Parameter Conditions Typ Max Unit
Table 40. Regulator modes transition times(1)
Symbol Parameter Conditions Typ Max Unit
tWULPRUN
Wakeup time from Low-power run mode to
Run mode(2) Code run with MSI 2 MHz 5 7
µs
tVOST
Regulator transition time from Range 2 to
Range 1 or Range 1 to Range 2(3) Code run with MSI 24 MHz 20 40
1. Guaranteed by characterization results.
2. Time until REGLPF flag is cleared in PWR_SR2.
3. Time until VOSF flag is cleared in PWR_SR2.
Table 41. Wakeup time using USART/LPUART(1)
Symbol Parameter Conditions Typ Max Unit
tWUUSART
tWULPUART
Wakeup time needed to calculate the
maximum USART/LPUART baudrate
allowing to wakeup up from stop mode
when USART/LPUART clock source is
HSI16
Stop 0 mode - 1.7
µs
Stop 1 mode and Stop 2
mode -8.5
1. Guaranteed by design.
Electrical characteristics STM32L432KB STM32L432KC
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6.3.7 External clock source characteristics
High-speed external user clock generated from an external source
In bypass mode the HSE oscillator is switched off and the input pin is a standard GPIO.
The external clock signal has to respect the I/O characteristics in Section 6.3.14. However,
the recommended clock input waveform is shown in Figure 12: High-speed external clock
source AC timing diagram.
Figure 12. High-speed external clock source AC timing diagram
Table 42. High-speed external user clock characteristics(1)
Symbol Parameter Conditions Min Typ Max Unit
fHSE_ext User external clock source frequency
Voltage scaling
Range 1 -848
MHz
Voltage scaling
Range 2 -826
VHSEH CK_IN input pin high level voltage - 0.7 VDDIOx -V
DDIOx V
VHSEL CK_IN input pin low level voltage - VSS - 0.3 VDDIOx
tw(HSEH)
tw(HSEL)
CK_IN high or low time
Voltage scaling
Range 1 7- -
ns
Voltage scaling
Range 2 18 - -
1. Guaranteed by design.
MS19214V2
VHSEH
tf(HSE)
90%
10%
THSE
t
tr(HSE)
VHSEL
tw(HSEH)
tw(HSEL)
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STM32L432KB STM32L432KC Electrical characteristics
148
Low-speed external user clock generated from an external source