Powering PCIe card with Xavier AGX, proper setup


I am looking to use a CoaXPress capture card with the Xavier AGX. The capture card physically fits the PCIe slot on the development board, but it requires additional power (6pin Molex).

I want to make sure I have a proper electrical setup that will not ruin anything, being that the +12v power I would supply through the Molex will be different than the +12v power from the development board.

I have not found a clear answer yet.

Jetson AGX GPIO control of PCIe power seems to indicate that the 12v supplied by the board could be disabled with proper configuration. This seems backed up by the diagram of the PCIe connection (Figure 2-1. PCIe x16 Connector Connections) in the Jetson_AGX_Xavier_Developer_Kit_Carrier_Board_Specification.

That diagram also shows the 3.3v connection.

Do I need to work through setting the GPIO to disable all power (12v & 3.3v) from the development board?
Has anyone used an externally power PCIe board with the AGX? If so what was the configuration/setup?


Usually, the cards have different domains that operate on 12V from the slot vs the external supply (at least discrete GPU cards from Nvidia are like that). So, it should be fine to let the 12V from the slot flow into the card along with supplies from the Molex connector. Check with the vendor of the card to confirm this.