Minimum TX2 system requirements


I’m designing a bare bones TX2 system. It only has Ethernet and a debug serial port. I am strapping CHARGER_PRSNT# to ground for auto-start. I am specifically interested in the minimum connections necessary to get a TX2 to boot. I know that Table 88 of the design guide has suggested external connections, but don’t put much stock in it as I checked the Carrier Board schematic and not a single one of the recommended terminations were followed.

Also, I have strapped my Carrier Board for auto-start and measured the key signals as there is no timing diagram for the auto-start case. Interestingly, CARRIER_PWR_ON goes true 200 mS after Vin is applied and VIN_PWR_BAD# goes false (high) ~300 mS after power is applied. This is the opposite of Figure 3 in the DG.

question 1: What is the absolute minimum external parts count (assuming Vin is external) required to boot a TX2?

Question 2: Given that the Carrier Board de-asserts VIN_PWR_BAD 100 mS after CARRIER_PER_ON what is the proper sequence for this bare bones system?


TX2 scope captures.docx (87.1 KB)

Hi, assume you are testing on your own board. The timing of VIN_PWR_BAD# is decided by dedicated circuit on carrier board (page 27 in schematic), do you make any changes to it?

Correct, I’m using my own board. The TX2 is powered by 12 volts instead of 19 so the timing will be different. Is the timing from application of input power until VIN_PWR_BAD# goes false at all critical? If so, what is the requirement? The timing diagram (Fig 3) is for a user power button case.

I can change the capacitor (equiv to C176) to change the timing as required if you can tell me the specification.


Do you measure the timing with dev kit? Is it same as with your custom board?

It’s weird that CARRIER_PWR_ON is active before VIN_PWR_ON#, in fact, the CHARGER_PRSNT# is controlled by VIN_PWR_ON# in module. Do you make any changes on these signals related circuit design?

I mis-spoke about the timing being reversed. It made no sense to me so I re-measured and discovered I had probed the wrong pin (easy to do with 400 pins on the back side). I have attached two scope captures from both the Nvidia carrier board and my own board. I have tried changing the timing capacitor on the VIN_PWR_BAD# line to make it take both more or less time than the Nvidia board. Neither had any effect. I suspect that I am missing something obvious. One clue is that while my board does not boot it is only consuming about 1.3W while the Nvidia board consumes 2.8 to 3.7W during boot up.

Note attachment is on original post as it was the only option


I checked in several times last night to see if we could get a more real time response between us. Did the attachment come thru OK? Since it looks like the power timing is correct I’m back to my original question. What is the minimum number of signals necessary to get a TX2 to boot.


problem resolved


Could you tell me how do you resolved problem? What is a minimal connection to Jetson TX2 that start booting? In my board I have connect VDD and VIN_PWR_BAD# short from jetson board to my board and Jetson on my board don’t boot but on Jetson board booting… I saw that when Jetson board generate a signal on VIN_PWR_BAD# when I connect power supply to Jetson board than VIN_PWR_BAD# have 0.600V (not 5V from internal pullup)… On jetson board the same Jetson TX 2 work correct…
If you want help me I will be thankful for help.