Question about power monitor with additional load on Jetson Thor

Robotics & Edge Computing Jetson Systems Jetson Thor
1

Hello NV team,

I have question about power monitor in the Jetson Thor design.(Please refer pic below)

In our system:

Block1 follows the Jetson Thor reference design.

Block2 is an additional customer-required power branch, with an estimated power consumption of around 300W.

My concern is that, in this architecture, the INA238 would measure the total input power, including Block 1 and Block 2. Because of this, I would like to ask the following:

1.Would this architecture cause any issue for Jetson Thor power management?
For example, could Jetson Thor be throttled or power-limited because the INA238 also measures the additional Block2 power consumption?

2.If yes, would software modification be required?

3.If we remove the INA238 power monitor from the design entirely, would that cause any issue?

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3

Hi solocigarette,

  1. Yes, if Block2 also goes through the INA238 shunt, its ~300 W will be added to VIN power and can easily hit the VIN limit (e.g. 168 W), causing unexpected CPU/GPU throttling.
  2. To keep this architecture you’d need to relax VIN power/OC limits in software, which NVIDIA does not recommend. Better: split VIN before the shunt so INA238 only measures Jetson + carrier.
  3. Removing INA238 is technically possible (system still runs with INA3221), but you lose total VIN monitoring and VIN-level OC protection, so it’s only advised if you provide equivalent external protection and accept that loss.

Please refer Jetson Thor Product Family — NVIDIA Jetson Linux Developer Guide to power consumption on Thor.