We are using the PTN5100 in a design that has a USB-C receptacle and a battery. I'd like to know if the following assumptions are correct, assuming there is no policy communication involved yet:
(a) When connected to USB-C and under a battery dead situation, the PTN5100 is only powered though VBUS (pin 2). VDD, VIO and VCONN_IN are all at 0V. This suffices to bring up the chip, possibly drive EN_USBFET1 low (based on Type-C connection state) but provide ~3.3V on V_MCUPWR in any case.
(b) When powered from the battery and with USB-C disconnected, VDD (=VIO) has 3.3V, VCONN_IN has 5V, but VBUS is at 0V. In this scenario, the PTN5100 still delivers ~3.3V on V_MCUPWR.
The problem we're seeing is that with a PTN5100BS, the above assumptions seem to be correct. With a PTN5100ABS however, we measure >=3.8V on V_MCUPWR in scenario (a) (which is too much), and only around 0.4V on V_MCUPWR in scenario (b).
Are there any differences between the two variants that are not mentioned in the datasheet, or is there anything else we are missing?