SLUSE13A January 2020 – May 2021 BQ76952
The BQ76952 device includes two pins (CFETOFF and DFETOFF) which can be used to disable the protection FET drivers quickly, without going through the host serial communications interface. When the selected pin is asserted, the device disables the respective protection FET. Note: when the selected pin is deasserted, the respective FET will only be enabled if there are no other items blocking them being reenabled, such as if the host also sent a command to disable the FETs using the serial communications interface after setting the selected pin. Both the CFETOFF and DFETOFF pins can be used for other functions if the FET turnoff feature is not required.
The CFETOFF pin can optionally be used to disable the CHG and PCHG FETs, and the DFETOFF pin can optionally be used to disable the DSG and PDSG FETs. The device also includes the option to configure the DFETOFF pin as BOTHOFF functionality, such that if that pin is asserted, the CHG, PCHG, DSG, and PDSG FETs will be disabled. This allows the CFETOFF pin to be used for an additional thermistor in the system, while still providing pin control to disable the FETs.
The CFETOFF or BOTHOFF functionality disables both the CHG FET and the PCHG FET when asserted.
The DFETOFF or BOTHOFF functionality disables both the DSG FET and the PDSG FET when asserted.