BQ29200,BQ29209,pdf(Voltage Pr

The bq2920x device is a secondary overvoltage protection IC for two-series cell lithium-ion battery packs that incorporates a high-accuracy precision overvoltage detection circuit and automatic cell imbalance correction.

The voltage of each cell in a two-series cell battery pack is compared to an internal reference voltage. If either cell reaches an overvoltage condition, the bq2920x device starts a timer that provides a delay proportional to the capacitance on the CD pin. Upon expiration of the internal timer, the OUT pin changes from low to high state.

If enabled, the bq2920x will perform automatic cell imbalance correction where the two cells are automatically corrected for voltage imbalance by loading the cell with the higher charge voltage with a small balancing current.