Question regarding power sequence on the Jetson TX2 Carrier Board


I am developing a custom camera host board for the Jetson TX2 Carrier Board and have a question regarding power sequencing on the Carrier Board.

My host board is connected to the Jetson TX2 Carrier Board over the Camera Expansion Connector. We use the 5V power supply to power our 6 cameras (over a Boost switcher) and the 3V3 and 1V8 supplies to supply the rest of the logic and control ICs on our host board (over 2 buck switchers on 3V3 rail). Both the boost and the two bucks are enabled only after 1V8 voltage from the Camera Expansion Connector is stable and our board will not draw almost any current before that happens.

We feel it is a solid design, but are puzzled by the note in the Jetson Camera Module Hardware Design Guide. Chapter 4 of the document on page 11 specifies (in table 4-1) the power sources available on the Camera Expansion Connector. Just below the table is a note stating that “Proper power sequence is required in order not to damage the Jetson TX1”.

From the Jetson TX2 OEM Product Design Guide I can see that the proper power sequence for the Jetson TX2 module happens before enabling any of the power rails on the Carrier Board (after CARRIER_PWR_ON signal is asserted). From this information I cannot see how would any use of voltage rails on the Carrier board or its modules damage the TX2 module as the Carrier board and its daughter boards (like our host) are powered down during the power up sequence of the Jetson TX2 module.

I would kindly ask anyone with the relevant information to confirm whether this is the case. That our use of 5V rail on our host board cannot damage the Jetson TX2 module.

We want to use the 5V supply for our cameras to ensure a future proof design as it provides enough power.

In the attachment I have provided a block schematic of the power subsystem of our board.

Camera_host_Power.pdf (29.6 KB)

Hi edo,

“Proper power sequence is required in order not to damage the Jetson TX1” just mean the power rails on carrier board should be up after “CARRIER_PWR_ON” enabled as you can see in power sequence in OEM DG. If your design would not change it, then should be OK.