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UCC5350-Q1: The introduction of GNTI and how to test it

Xun Wang
Prodigy 30 points
Part Number: UCC5350-Q1

Tool/software:

Hi,

I'd like to learn about the isolation test standard GNTI(Ground Noise Transient Immunity Testing ), and I only found a video about it. The title of the video is "GNTI Testing of Reinforced Digital Isolators". Do you have other paper or materials about it? I'd like to know the difference between CMTI and GNTI, and I'd also like to know how to test GNTI. 

Thanks!

Best Regards

  • 0
    TI__Genius 17646 points

    Hi Xun,

    In the Isolated gate drivers group, we do not have an amplifier bank. We have a TBMDA3 RF Power amplifier to apply the ground noise. We monitor the output in the same way that the video describes. I have some internal test procedures, but they are marked as NDA confidential, unfortunately.

    CMTI is just one big step, but it can be very high dV/dt and also very high amplitude. We use a Barth pulse forming network and a Barth ramp generator for these tests, and the results are accurate enough for datasheet specs.

    GNTI is a harder test to perform. You have to create a high frequency, high amplitude spectrum, and apply that signal consistently across the isolation lane without reflections. So far, we have only really been able to get good results up to 300MHz. At higher frequencies than that, the sine wave becomes distorted and the amplitude has peaks and troughs from standing waves in the coax transmission line. We are currently working on improving our matching, but there is no easy solution. 

    I have suggested using a LC resonant switch node in a double pulse test to generate a "ping" at a high amplitude and frequency, right across the barrier. But that would be a single point or two, and does not sweep a spectrum, which is a goal of a GNTI test.

    Best regards,

    Sean