Other Parts Discussed in Thread: TIDA-010208
Tool/software:
Hey TI Experts,
We are using the Pre-discharge functionality of the BQ76952 in high side configuration.
We are facing the following issues:
1) When the AFE is turned on for the first time i.e., when the cell connectors are connected for the first time the voltage appearing on the PDSG pin with respect to AFE ground i.e., Battery Pack negative is (Pack voltage-7.5V) for the set amount of time before transitioning to the DSG FET occurs.
After which the voltage on the PDSG pin reduces to (Pack Voltage-2V) which implies not turning OFF completely.
2) When Battery Pack positive is connected then the voltage on the PDSG pin with respect to AFE gnd i.e, Battery pack negative is (Pack voltage+1V) i.e., Vgs is 1V for the set time of PDSG. After which the Vgs across the P channel PDSG FET reduces to 0.6V.
Note: the DSG and CHG pins worked as expected and have a Vgs off 11V.
What might be causing this behaviour?
Would like your precious input on the same.
The schematic is attached for your reference
The configuration register settings are as follows:
BQ769x2_SetRegister(FETOptions, 0x3A, 1);
BQ769x2_SetRegister(PredischargeTimeout,0xC8,1);
BQ769x2_SetRegister(PredischargeStopDelta,0x00,1);
BQ769x2_SetRegister(ChgPumpControl, 0x01, 1);
BQ769x2_SetRegister(DAConfiguration, 0x06, 1);
Thanks and regards
Ibrahim Saqib
