TCA7408 8-bit I/O Expander



Texas Instruments TCA7408 8-bit I/O Expander

Texas Instruments' 8-bit I/O expander for the two-line bidirectional bus (I²C)

Texas Instruments' 8-bit I/O expander for the two-line bidirectional bus (I²C) is designed to provide general-purpose remote I/O expansion via the I²C interface [serial clock (SCL) and serial data (SDA)]. The major benefit of this device is its wide VCC range. It can operate from 1.65 V to 3.6 V on the GPIO-port side and 1.65 V to 5.5 V on the SDA/SCL side. This allows the TCA7408 to interface with next-generation microprocessors and microcontrollers on the SDA/SCL side, where supply levels are dropping down to conserve power.

The bidirectional voltage-level translation in the TCA7408 is provided through VCCI. VCCI should be connected to the VCC of the external SCL/SDA lines. This indicates the VCC level of the I²C bus to the TCA7408.   TCA7408 Datasheet
  Features
  • Operating power-supply voltage range of 1.65 V to 3.6 V
  • Allows bidirectional voltage-level translation and GPIO expansion between:
    • 1.8 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V GPIO port
    • 2.5 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V GPIO port
    • 3.3 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V GPIO port
    • 5 V SCL/SDA and 1.8 V, 2.5 V, 3.3 V GPIO port
  • Standby current consumption of <2 µA at 1.8 V
  • Active current consumption of:
    • <2 µA at 1.8 V 100 kHz clock
    • <5 µA at 1.8 V 400 kHz clock
  • 100 kHz, 400 kHz fast mode
  • Internal power-on-reset and watchdog timer

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Texas Instruments
Part Number
Digi-Key
Part Number
Packaging Voltage - Supply Package  
TCA7408ZSZR 296-30074-2-ND Tape & Reel 1.65 V ~ 3.6 V 16-uCSP TCA7408ZSZR Datasheet
296-30074-1-ND Cut Tape
296-30074-6-ND Digi-Reel®

Evaluation Module
Texas Instruments
Part Number
Digi-Key
Part Number
Features  
TCA7408-5405EVM 296-30147-ND   •  Works with MSP430 Launchpad
  •  Illustrates the use of TPL0401DPOT for color mixing
  •  TCA7408 used for key press detection
  •  Shows the use of single wire self timed interface in TCA5405
  •  Color mixing and LED blinking control
TCA7408-5405EVM User's Guide