The BQ28Z620 device controls two external N-Channel MOSFETs in a back-to-back configuration for battery protection. The charge (CHG) and discharge (DSG) FETs are automatically disabled if a safety fault (AOLD, ASSC, ASCD, SOV) is detected, and can also be manually turned off using AFE_CONTROL[CHGEN, DSGEN] = 0, 0. When the gate drive is disabled, an internal circuit discharges CHG to VC2 and DSG to PACK.

The charge pump current consumption gets higher when the MOSFET gate leakage current (IGSS) increases. Refer to the MOSFET data sheet to select the proper MOSFET.

To minimize device quiescent current in SLEEP mode, the CHG and DSG gate drive voltage could be reduced to 5.75 V by setting AFE_CONTROL_REGISTER[PMPDRV] = 0.