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UCC2818: Mosfets are failing with UCC2818 PFC(How over current protection can implement in UCC2818 PFC)

Aneesh TS
Expert 1735 points
Part Number: UCC2818

Dear TI experts,

We are doing 3KW PFC design with UCC2818. w made the PFC working . But Mosfets are failing frequently while testing due to over current. When an Over current event is happening instead of switching OFF the PWM pulses Mosfets are failing first.How over current protection can implement in UCC2818 PFC?

Regards

Aneesh

  • 0
    TI__Mastermind 34465 points

    Hello Aneesh,

    The UCC2818 has a calculator tool that allows you to set up the input power limit for your pfc converter.

    If you know your operating conditions you can use this calculator to determine the operating parameters for your boost MOSFET.

    It is then just a mattter of selecting a MOSFET with the rated voltage and current from the catalogue.

    You should start out at light loads . Monitor the V_DS  and I_DS of the MOSFET then slowly increase the load as you debug your circuit.

    Regards

    John

  • 0 in reply to John Griffin1
    Expert 1735 points

    Dear John,

    My PFC circuit is working fine if everything is fine. We have used the design tool and correctly set the power limit also. We have Full bridge converter stage followed by PFC.But if there is a short in the full bridge  converter output or if there is any other kind of mistakes while debugging, The PFC mosfet is failing. But actually The PFC should detect the over current and shut down its Mosfet PWM pulses before fails, But it is not happening.

    Regards

    Aneesh

  • 0 in reply to Aneesh TS
    TI__Mastermind 34465 points

    Hello Aneesh,

    Not sure how I can help if you say your pfc is working fine with the correct power limit.

    Let me know if you need further help.

    Regards

    John