USB Inrush current tool

Technical Discussion
1

Hi,

I have been able to check USB inrush compliance by saving a csv file and using USBET20.

Is there a way of integrating the tool as you describe in your YouTube video?

2

Yes @deonm, Joulescopes still provide one of the easiest ways to perform USB inrush pre-compliance testing. The entire process takes less than a minute!

The process has changed slightly since the video. Here is how:

Configure your setup

  1. Download and install USBET20 from the USB-IF on your Windows host computer. USBET20 only runs on Windows.
  2. Download and install the latest Joulescope UI
  3. Start the Joulescope UI and connect your Joulescope. For your JS220, you may want to use the optional USB front panel or the third-party uUSB front panel.

Measure USB Inrush

  1. Select the fixed 10 A range. No need for current range switching for USB inrush testing.
  2. Connect your target device to capture the inrush event.
  3. Pause the capture.
  4. Add and position dual markers around the inrush event. You should have about 10 milliseconds before and 100 to 150 milliseconds after. USBET20 requires at least 100 milliseconds after.
  5. Right-click on one of the dual markers, select Analysis → USB Inrush
  6. The Joulescope UI automatically invokes the USBET20 tool, which will display the results in your default browser.

Here is a quick video showing the process:

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