What is the behavior if back-feeding the nPM1100's VCC output, such as if VCC is supplied from a external supply and no battery or USB power is present.
I have been bringing up a new board on a bench setup where I powered the board's VCC from an external power supply, thus back-feeding the nPM1100.
I've been running it at 3 volts which is the selected operating voltage for the device when running from a battery or USB power.
This has worked fine for the last few days.
Unfortunately this morning the external power supply was set to 3.5 volt which it appears to have damaged the nPM1100. The external power supply went into current limit at 80mA.
Only when I removed the inductor for the buck regulator did the board come back up.
Now when rereading the datasheet I realize I might have exceeded the device's maximum ratings, but I am not 100% sure if that is the case.
Nevertheless I'd like to know if back-feeding the nPM1100 is allowed or recommended and its limits as I'm needed to support a number of developers and manufacturing during in-system programming and testing
