Maxim Distributor

MAX14920/21 AFEs


Maxim's high-accuracy 12-/16-cell measurement AFEs


Maxim's MAX14920/MAX14921 battery-measurement analog front-end devices accurately sample cell voltages and provide level shifting for primary/secondary battery packs up to 16 cells/65 V (max). The MAX14920 monitors up to 12 cells, while the MAX14921 monitors up to 16 cells. Both devices simultaneously sample all cell voltages, allowing accurate state-of-charge and source-resistance determination. All cell voltages are level-shifted to ground reference with unity gain, simplifying external ADC data conversion.

The devices have a low-noise, low-offset amplifier that buffers differential voltages of up to 5 V, allowing monitoring of all common lithium-ion (Li+) cell technologies. The resulting cell voltage error is ±0.5 mV. The devices’ high accuracy make them ideal for monitoring cell chemistries with very flat discharge curves, such as lithium-metal phosphate. External FET drivers support passive-cell balancing.

Integrated diagnostics in the devices allow open-wire detection and undervoltage/overvoltage alarms. The devices are controlled by a daisy-chainable SPI interface. The MAX14920 is available in a 64-pin (10 mm x 10 mm) TQFP package with an exposed pad. The MAX14921 is available in an 80-pin (12 mm x 12 mm) TQFP package. Both devices are specified over the -40°C to 85°C extended temperature range. View MAX14920/21 Video
Maxim's MAX14920/21

Features
  • High accuracy
    • ±0.5 mV (max) cell voltage
    • Simultaneous cell voltage sampling
  • Integrated diagnostics
    • Open-wire and short fault detection
    • Undervoltage/overvoltage warning
    • Thermal shutdown
  • Low power
    • 1 µA/10 µA cell current draw
    • 1 µA shutdown mode
  • High flexibility
    • SPI interface
    • 12-cell and 16-cell versions
    • 6 V minimum (3 cells) operation
    • 0.5 V to 4.5 V cell voltage range
    • Integrated cell-balancing FET drivers
    • Integrated 5 V LDO

Applications
  • e-Transportation energy packs
  • Energy storage packs
  • Industrial battery backup systems
  • Telecom battery backup systems

Digi-Key P/N Manufacturer P/N Description
MAX14920ECB+-ND MAX14920ECB+ IC AFE 12/16CELL MEASURE TQFP Datasheet
MAX14921ECS+-ND MAX14921ECS+ IC AFE 16CELL BATTERY TQFP