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UCC28730-Q1: UCC28730-Q1

Part Number: UCC28730-Q1
Other Parts Discussed in Thread: UCC28730

Hi 

From the simulation result, controller will stop working(no DRV) when VOUT rise to the design value 12V, it looks like the VS level is above 4.6V and trigger the OVP,

I want to consult how to filter VS noise? it looks VOUT is normal. should add RCD clamp circuit to VIN? how to calculate these parameters 

  • Hello,

    The UCC28730 use primary side regulation and fault sensing.  The following like will bring you to an application note that describes how input under voltage lockout, over current protection and OVP protection works for these controllers.  It also covers the most common issues and how to resolve.  https://www.ti.com/lit/pdf/sluaac5

    This application note also shows what the CS, Aux, VDD and Vout signals should look like.  By evaluating these nodes it should be possible to figure out why the design is shutting down and how to resolve the issue. 

    It was mentioned that it was believe to be OVP.  You might want to double check that you have a pre-load resistor to ensure the design does not go into OVP under no load condition.  Putting a resistor that draws 1 to 2 mA should be placed on the output.

    Regards,