thanks,
Im using the 27w official pi PSUs (ie these: https://www.raspberrypi.com/products/27w-power-supply/). (on USA AC mains/prongs)
what seems weird is that great thread you linked, seems to discuss the same issue we are seeing, but when the pi is powered via GPIO (and not via USBC, like is the issue here).
So if im reading that thread correctly, it seems the issue i (we) are seeing is an issue more so with the official pi power supply not ramping up voltage quickly enough in some scenarios (or an overly aggressive PMIC power-on-reset threshold on the pi5 side).
quote:
(is there a way to disable the PMIC power-on reset threshold maybe? even though the onus would be on ME to not give the pi5 a wrong/bad usbC power supply voltage).
thanks
Im using the 27w official pi PSUs (ie these: https://www.raspberrypi.com/products/27w-power-supply/). (on USA AC mains/prongs)
what seems weird is that great thread you linked, seems to discuss the same issue we are seeing, but when the pi is powered via GPIO (and not via USBC, like is the issue here).
So if im reading that thread correctly, it seems the issue i (we) are seeing is an issue more so with the official pi power supply not ramping up voltage quickly enough in some scenarios (or an overly aggressive PMIC power-on-reset threshold on the pi5 side).
quote:
does that sound right?Dunno, the debounce is not specified in our datasheet. The critical window is the rise from ~3.5V to 4.1V (PMIC power-on reset threshold to UVLO threshold).
The overvoltage protection only applies to the USB-C port. It's there to stop fake/badly-behaving PD power supplies from incorrectly supplying 9/15/20V and exploding the Pi.
(is there a way to disable the PMIC power-on reset threshold maybe? even though the onus would be on ME to not give the pi5 a wrong/bad usbC power supply voltage).
thanks
Statistics: Posted by rpiUser255e — Tue Aug 26, 2025 10:57 pm