"System throttled due to Over-current."

Autonomous Machines Jetson & Embedded Systems Jetson Nano
#1

I’m using a Jetson Nano Developer Kit B01 with a fresh install of Jetpack 4.4.1.
It’s powered through the barrel connector, using a 5.15V, 4A USB power brick.

Immediately after displaying the Desktop, a notification appears that says “System throttled due to Over-current.”

After acknowledging the warning, it disappears.
In the 10W power mode (“MAXN”), even just opening a Terminal window will bring the warning back.

The Nano consumes ~0.7A - 0.9A. Powering through the microUSB-Port does not change the behaviour.

I do not have a way know if the performance is actually reduced, yet.

#3

hello couka,

there’s a built-in under voltage and over current protection mechanism.
please refer to developer guide, you may check Under Voltage and Over Current Protection session for more details.
you may also access TegraX1 Technical Reference Manual from download center,
please refer to Chapter-40, [Thermal sensor and thermal throttling controller] for the behavior of over-current detection.
thanks

#4

Hello JerryChang,

I read through the resources you mentioned. Unfortunately I’m still clueless whether there is something wrong with my unit.

Is there a standardized, quantifiable method to verify the performance of the Jetson Nano?

Thanks for your help.

#6

The issue here is NOT an overcurrent condition. It’s undervoltage. The notification is misleading.

I finally got around to put a scope on the barrel jack input and found the cause: Both my microUSB and my barrel jack cable just were too long/low crossection to deliver enough current while staying within voltage spec. As a result, the voltage dropped from 5.17V to just 4.70V at a current of less than 1.0A.
I shortened my cable as much as possible, the voltage now stays >4.9V and the notification seems to be gone for good.

My guess is that the notification is triggered by the Kernel warning “OC ALARM 0x00000001”, which could signify over-current, but more commonly it’s triggered by under-voltage, and some developer just assumed “OC” always means “Over-current”.

3 Likes
#8

I have the same issue, I use an AC adaptor (5V-3A) connected to USB-C (Jetson Nano 2GB) and the notification appears while running an Object detection model so I suppose as @couka said that is an under-voltage problem due to high requirements of the model.