SLUAAN9 February   2023 BQ769142 , BQ76942 , BQ76952 , BQ76972 , ISO1640 , LM5168

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Stacked AFE Communication
    1. 2.1 Data Communications
    2. 2.2 Control Signals
  5. 3High-Side N-Channel MOSFET
    1. 3.1 Discharge MOSFET Turn On and Off Processes
    2. 3.2 PACK Port High Voltage
    3. 3.3 Quickly Turning Off the Discharge MOSFET
  6. 4Current Consumption of Stacked Groups
  7. 5Summary
  8. 6References

2 Stacked AFE Communication

To cover battery packs with higher than 16s cells, and greater than 60-V applications, two BQ769x2 family monitors are stacked to monitor up to 32s battery cells. Each BQ769x2 monitors up to 16s battery cells in one group. The bottom BQ769x2 shares the same ground with the whole pack and MCU, while the top BQ769x2 references the stack voltage of the bottom group. Therefore, an isolation device or a high-voltage level shifter is required for the communications between the top BQ769x2 and the MCU.