Topic has been discussed here viewtopic.php?p=2194239&hilit=Rise+time#p2194178
I've asked for the min time but that's not speced.There is an undervoltage lockout on the PMIC that will activate at 4.1V, forcing the STANDBY state, which incidentally cuts off VBUS as well. This is intended to prevent boot looping or cycling VBUS on/off if a weak PSU is used.
With a slow rise time, the undervoltage lockout will operate because the time spent with the PMIC powered but below the critical threshold exceeds the UVLO debounce time.
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).
So what is the min rise time that a 5V voltage for powering over GPIO would need?
Also looks like 5V from GPIO is bypassing said over voltage protection set, right?
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.
Statistics: Posted by aBUGSworstnightmare — Thu Jul 11, 2024 4:32 am