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UCC28180: PFC Mosfet Failure

PSENGINEER Intelux
Intellectual 260 points
Part Number: UCC28180

Im using UCC28180 For 500W PFC application but Mosfet fails at no load condition when i directly switch on board  at 240V input. also sometimes Ucc28180 IC gate and ground pin get short.

  • 0
    TI__Guru 60825 points
    Can you provide your MOSFET datasheet for our review?

    What do you mena "i directly siwtch on board at 240V"? Do you mean you power on board from 240V input?

    Please also provide your schematics for our review.
  • 0 in reply to Hong Huang
    Intellectual 260 points

    Thank yo sir for your quick reply,

    My issue with this design is mosfet failure when i power Up board directly at 240Vrms. voltage range for This board is 90V to 265V, when i power up by increasing input voltage from 0V  then there is no issue with mosfet. but when i directly power up board at 240Vrms the mosfet get damaged also UCC28180 Gate pin shorted to gnd.

    Here i am  mentioning  some important components that I'm using in the circuit

    PFC Mosfet: ST38N65M5

    PFC Diode: U10A60

    PFC Controller IC: UCC28180

    PFC Shunt Resistor: 10mOhm

    Pfc Output cap: 270uF/450V

    Below i have provided the schematic, help me to resolve my issue

  • 0 in reply to PSENGINEER Intelux
    TI__Mastermind 34465 points

    Hello Vinod,

    The reason your Q2  FET is failing  is because the UCC28180 needs to sense a negative voltage on the ISENSE input pin.

    I marked up your schematic and it now shows how to  cut the ground lead and rearranhe the current sense resistor.

    SKM_C25819053108330.pdf

    You can check this with any of the reference designs for the UCC28180

    Regards

    John

  • 0 in reply to John Griffin1
    Intellectual 260 points

    Dear Sir,

    i have already taken this trial suggested by you by refering reference design but, still mosfet is fails when directly powered up at 240Vrms.

    if The PFC is discharged & then powered up the board then there is no issue but, without discharging PFC when i switch on off the input power PFC mosfet Fails, Control Ic fails.

  • 0 in reply to PSENGINEER Intelux
    TI__Guru 60825 points

    You need to measure MOSFET Vds waveform during 240Vac directly power on and check Vds if exceed its datasheet specifications. If so, you may need to change your MOSFET with a higher voltage rating or using some clamping circuit to clamp Vds below its specified Vds.

    If the failure due to violate MOSFET current current rating, you need to change the MOSFET with a higher current rating.

    We cannot find the MOSFET datasheet of that part number you provided. But you can do it by yourself and follow the above. The MOSFET is damaged usually from the above. So you need to check them and find a proper MOSFET for your design.