BQ25713: How do i limit the charger Vin value

Hey Elad,

You can do several things to achieve this.

If you program the InputVoltage() register to a value higher than the VBUS voltage you want to limit, it force the charger deep into VINDPM, which automatically reduces the charge current to the minimum value. Keep in mind that the SYS voltage will collapse to the battery voltage at this point. Additionally, the InputVoltage() register is automatically detected whenever a valid input is applied, meaning that this method will not work automatically if you apply a 9V input, remove it, and then later apply a 5V input. You will have to adjust the register each time.

Additionally, you can use the FORCE_LATCHOFF bit in the ChargeOption1() register with the integrated independent comparator to monitor the VBUS voltage. If the VBUS voltage is below a certain threshold and the comparator is active and trips, it will also disable the converter, disabling charge. This will have the same impact to the SYS voltage.

Lastly, you can utilize the internal ADC registers to monitor the VBUS voltage and have a software implementation that disables charge whenever the VBUS voltage is near or below your 5V setpoint.

Regards,

Joel H