SLUAA81A October   2020  – February 2022 BQ769142 , BQ76922 , BQ76942 , BQ76952

 

  1.   Trademarks
  2. 1Introduction
  3. 2Cell Balancing Circuit Considerations
    1. 2.1 Internal Cell-Balancing Circuit Design
    2. 2.2 External Cell-Balancing Circuit Design Using N-Channel FETs
    3. 2.3 External Cell-Balancing Circuit Design Using P-Channel FETs
    4. 2.4 External Cell-Balancing Circuit Design Using BJTs
    5. 2.5 Voltage Measurement Accuracy During Balance
  4. 3Stand-Alone Balancing Algorithm and Settings
  5. 4Considerations for a Host-Balancing Algorithm
  6. 5Timing Information
  7. 6Debugging Common Issues With Cell Balancing
    1. 6.1 Using a Resistor Divider as a Cell Simulator
  8. 7References
  9. 8Revision History

Abstract

The BQ769x2 battery monitor family (which includes the BQ76952, BQ76942, and BQ769142) features a cell-balancing function that can run autonomously or can be controlled by a host. This document describes how to use the cell-balancing feature of the device in a battery pack application. Increasing the current capability of the IC using external FETs and BJTs is described. The algorithm for balancing in stand-alone mode is described as well as considerations for implementing a host-controlled balancing algorithm which avoids damage to the IC.