Power pins during CM3 power off


For my project, I’d like to know which pins on the Fin are powered and which aren’t when the Pi is switched off by the coprocessor. I couldn’t find a list of these anywhere, but from the datasheet and schematics I think that the following is true:

  • EXP 3V3 is powered
  • HAT 5V is powered
  • HAT 3V3 is NOT powered
  • mPCIe is NOT powered
  • USB is NOT powered (both the header and the ports)

Can anyone confirm?


Hi Marten,
Let me get in touch with our FIN engineers to confirm this 100%, but from my point of view your list looks good.
Kind regards,

Hi @martenjacobs that is correct:

  • Only the the 5V pins (pins 2 and 4) on the compute module header (HAT) are powered
  • All the pins on the coprocessor header are powered
  • mPCIe and USB are not powered.


OK, so that would mean the 5V HAT pins are not powered either? From what I see in the schematics the 5V is powered directly from U27, so I’d say they would stay powered. Or am I missing something?

@martenjacobs, sorry for the confusion, the 5V in the HAT header is powered. I edited my previous message.