This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC28704: Conductive Susceptibility

Part Number: UCC28704

I am currently testing Conductive Immunity/Susceptibility (IEC 61000-4-6) on a product using the UCC28704 and the supply voltage collapses at levels 3(10Vrms) and level 2(3Vrms).

Once the field is removed the supply returns to normal. I suspect pin 6 (VS) is being affected. I have verified the UCC28704EVM also exhibits this problem.  What do you recommend to solve this issue. 

  • Hello,

    If the UCC28704 is shutting down you noise immunity test maybe accidently triggering and over voltage protection (OVP) fault, and input under voltage (UVLO) fault or an over current fault.

    I have attached a draft of an application note that discusses how the common issues with primary side fault sensing and how to resolve them.  You may find this information useful in trying to figure out what is causing your issue.

    SLUAAC5 8 4 21.pdf

    The VS pin does monitor OCP and UVLO.  If your test is injecting noise into this pin it could causing the device to shut down due to a fault.  You could also consider putting the design meatal shielding that will work as a Ferriday cage.  This may remove the issue as well.