Hard Power Off, coming back up

I have a custom carrier board I designed to use the Nano, Xavier or Orin Jetson SODIMM boards. The carrier board is designed to go into a system that supplies power and it controls when the power comes on or goes off.

The end system will not be writing internally so a hard power off from a linux perspective is fine. We’ve deployed this with the raspberry pi compute module in a similar scenario and have never had an issue on any in the field units after 5+ years.

So I want to use this same system on the Jetson platform. I designed the carrier using the dev kit as a starting point (thanks for that!) and I have discovered on interesting issue. Let me describe.

If the unit is running and I remove power, wait a few seconds, then plug back in, it never comes up. If I instead remove the module from the SODIMM connector for a few seconds and plug back in, then apply power again to the system, it comes up no problem.

My initial guess is the giant caps from the design on the power going into the module. It’s 3 - 3300uF caps. Do I need to include these if I am okay with a hard power down? Can I get some guidance on this aspect of the design.

Everything else seems to be working fantastic!

It looks like there are too many capacitors on carrier board that will cause the discharging too long. For power loss, below sequence/timing in Design Guide doc should be guaranteed. You should probe the power down sequence of your design and to reduce capacitors based on fulfilling the sequence request.
powerdown

Excellent! Thanks so much for the pointer!! I will scope this immediately!

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