Powering AGX Xavier with DC-DC Converter

Hello

We have 12V batteries available and they cannot power the AGX Xavier despite having enough voltage to do so, the documentation specifies voltages in the 9-19 range, I suspect it’s due to current spikes in the booting process leading to a sudden drop of voltage (dV/dt >= 0.5 V/s leads to a shutdown of the Xavier), so I got a DC-DC Converter with a suitable input and voltage range. I can output 1-12V from the DC DC converter but the problem remains, a sudden drop in voltage nullifies the boot process.

Has anyone had a similar issue? My next step will be using a capacitor with a suitable voltage rating (~15V) but I was interested in listening to the community’s thoughts.

Has anyone had similar issue?

Hi, it could be the voltage drop by current spike during boot. A big capacitor or stronger power supply is necessary if so. Have you captured the voltage drop with scope?

The Jetson AGX is very, VERY sensitive to input voltage. The lower the voltage is, the more sensitive it is.

I have a 2200 35V uF capacitor straight across the 19V input, and I power it with a 16 V LiPo battery with XT60 connectors, and it works mostly OK. Note that, for capacitor voltage rating, you want much higher voltage than your expected voltage if you have the choice, because this will make the capacitor last much longer. Each 10V of additional voltage rating above what you actually supply, and each 10 degrees C of additional temperature rating above actual ambient, will up to double the lifetime of the part. (These are rules of thumb, check the actual supplier data sheets and support literature for more exact numbers.)

You need to make sure that your battery is capable of high current delivery, and that your wires are as short as possible, and ideally that you are in the upper range of the input voltage, for a battery powered system to work well.

Also, the barrel connector itself seems fairly sensitive; when my system is jostled, it will sometimes reset. I have been meaning to solder a real XT-60 connector to the devkit board, but haven’t gotten around to it, so I don’t know if this would actually fix it or not.

I’ve confirmed voltage drops with an oscilloscope and I’m trying to find out what capacitance I need to power it. Right now, a 25V 47mF capacitor with 12V of input almost does the trick when the Xavier is isolated, but connecting the Xavier to an HDMI monitor + USB peripherals caused even more voltage drops and I ended up corrupting the OS.

Next step is to connect a plastic dielectric capacitor in parallel with the electrolytic to try to phase out high frequency noise.

I’m very much limited to the power source, it’s 12V @ 2.5A and it’s a few years old. I’m certain that were I allowed to use a dedicated battery, this issue would be half as difficult.

Just as a ballpark estimate I’d say the capacitor should be at least 1000uF.