I'm designing a device using the MCP73871-2CC, which I would like to be able to vary its charge rate via the SEL pin. An IC would be needed that could detect the difference between a standard USB port (set 500 mA charge rate) and a dedicated charging port (set 1 A charge rate). The system is using a USB-C receptacle if that changes anything.
So far I have found the BQ24392, but I am unable to provide the GOOD_BAT signal using 3V3 as I would like the system to be able to charge even when the MCU and its supply are off, where the charging and USB chips would be powered by VBUS. Would I be able to attach GOOD_BAT to VBUS (5 V in my case) in order to 'trick' the chip into allowing charging? I have seen varying information saying that the signal pins on this chip are only 3.3 V tolerant despite the absolute maximum ratings stating 7 V max and the recommended conditions saying VBUS max on the GOOD_BAT pin, but the eval board states that they should never be connected to VBUS. Why is this and would an LDO or voltage divider level shifter be the solution here from VBUS to 3.3 V?
