BQ76940

• AFE monitoring features
  • Pure digital interface
  • Internal ADC measures cell voltage, die temperature, and external thermistor
  • A separate, internal ADC measures pack current (coulomb counter)
  • Directly supports up to three thermistors (103AT)


• Hardware protection features
  • Overcurrent in Discharge (OCD)
  • Short Circuit in Discharge (SCD)
  • Overvoltage (OV)
  • Undervoltage (UV)
  • Secondary protector fault detection
• Additional features
  • Integrated cell balancing FETs
  • Charge, discharge low-side NCH FET drivers
  • Alert interrupt to host microcontroller
  • 2.5-V or 3.3-V output voltage regulator
  • No EEPROM programming necessary
  • High supply voltage absolute maximum (up to 108 V)
  • Simple I²C compatible interface (CRC option)
  • Random cell connection tolerant

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The bq769x0 family of robust analog front-end (AFE) devices serves as part of a complete pack monitoring and protection solution for next-generation, high-power systems, such as light electric vehicles, power tools, and uninterruptible power supplies. The bq769x0 is designed with low power in mind: Sub-blocks within the IC may be enabled or disabled to control the overall chip current consumption, and a SHIP mode provides a simple way to put the pack into an ultra-low power state.

The bq76920 device supports up to 5-series cells or typical 18-V packs, the bq76930 handles up to 10-series cells or typical 36-V packs, and the bq76940 works for up to 15-series cells or typical 48-V packs. A variety of battery chemistries may be managed with these AFEs, including Lithium Ion, Lithium iron phosphate, and more. Through I²C, a host controller can use the bq769x0 to implement many battery pack management functions, such as monitoring (cell voltages, pack current, pack temperatures), protection (controlling charge/discharge FETs), and balancing. Integrated A/D converters enable a purely digital readout of critical system parameters, with calibration handled in TI’s manufacturing process.