We have designed a custom carrier board for a Jetson Nano. We have wicked power up problem that occurs, typical at high or low temperatures, although we have seen this problem at room temperature on certain units.
Below is a bad boot:
Below is a good boot:
We followed the Jetson Nano carrier board power sequence design. In most cases we used the same components. From what we can tell we are meeting the requirements of the Jetson Nano Product Design Guide V2.2 page 13 and on.
In the screen shots, 5V0_Ride is a super cap/mains power line. 5V0_SOM is the 5V0_Ride signal that goes through a FET. NANO_EN is POWER_EN (Nano), REG_EN is SYS_RESET (Nano), SHDN_REQ is SHUTDOWN_REQ (Nano).
The only think I can think of that would cause this issue is a brown out on the PMIC on the Jetson. But we don’t see the power supply dip when we apply power to the Jetson or raise POWER_EN high on the SOM.