The BQ27Z758 offers direct battery sensing through differential battery sensing pins BAT_SP and BAT_SN for accurate battery voltage measurement and detection. BQ27Z758 battery sensing path includes protection and isolation to minimize any leakage and coupling issue. The cell isolation includes a combination of buffered and resistive options. Firmware configuration allows seamless auto-transition between the two sensing schemes. The battery sensing buffer is powered from the PACK pin.

For accurate battery voltage sensing when using the sensing buffer, the PACK pin must be powered and VPACK > VBAT + 0.7 V. The sensing protection thresholds (BCP, BCN, BDP, and BDN) provide short detection for the battery sensing output pins, and places the battery sensing output pins in a high impedance state when triggered. The BQ27Z758 battery sensing has firmware programmable offset options for applications where differential output voltage needs to be shifted to overcome an input range limitation. The offset voltage selected should never exceed the sensing protection thresholds, because this causes false battery sensing faults.