The built-in input overvoltage protection to protect the device and other downstream components against damage from overvoltage on the input supply (voltage from V_USB or V_IN to PGND). During normal operation, if V_SUPPLY > V_OVP, the BQ2416xx turns off the PWM converter, turns the battery FET and BGATE on, sends a single 128-μs pulse is sent on the STAT and INT outputs and the STATx and FAULT_x bits of the status registers and the battery/supply status registers are updated. Once the OVP fault is removed, the STATx and FAULT_x bits are cleared and the device returns to normal operation.

To allow operation with some unregulated adapters, the OVP circuit is not active during Bad Source Detection. This provides some time for the current sink to pull the unregulated adapter down into an acceptable range. If the adapter voltage is high at the end of the detection, the startup of the PWM converter does not occur. The OVP circuit is active during normal operation, so if the system standby current plus the charge current is not enough to pull down the source, operation is suspended.