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UCC21530-Q1: Noises in Gate Driver Output

RAJAT TIWARI
Prodigy 40 points
Part Number: UCC21530-Q1
Other Parts Discussed in Thread: UCC21530, UCC21551, ALLIGATOR

Tool/software:

Hi

I am using UCC21530 for driving the Totem pole PFC MOSFET when the input is around 50V there are some noises seen in the output of gate driver.

Enclosed images shows the noises in the output of Gate driver When the MOSFET is connected

Switching frequency is 50kHz given from functional generator.

Duty ratio is 10%

  • 0
    TI__Mastermind 23206 points

    Hi Rajat,

    There is an update to the UCC21530 that you should try to use instead. It is the UCC21551.

    Is this noise consistent? It looks like you only have one cycle shown. It almost looks like the ground of the probe became disconnected, but it recovers? There have been reports of a high-Z state with the UCC21530, due to brown-out conditions of the internal LDO. Using the new device would solve that issue.

    D and B are both high at the same time. Do you have a schematic to help me understand the system level circuit? C looks like the switch node.

    There is a small amount of ringing following the falling edge of each pulse, maybe this ringing is simply extended if one of the outputs does not go LOW correctly.

    Best regards,

    Sean

  • 0 in reply to Sean Cashin
    Prodigy 40 points

    Hi Sean

    Thanks for reply..

    I will explain the waveform more clearly 

    C represents the Voltage across Drain to source of the switching mosfet.

    B represents the output of the gate driver.

    D represents the input to the gate driver.

    The schematic is attached for your reference

    Giving input to gate driver from function generator to INA pin and output from OUT A.

  • 0 in reply to RAJAT TIWARI
    TI__Mastermind 23206 points

    Hi Rajat,

    Can you use the UCC21551 instead?

    It looks like an intermittent problem with your ground, since it affects all signals equally. It is hard to say if this is a real signal, since it is instantaneous and doesn't slowly change like a real signal.

    Maybe blow on the connectors and squeeze the alligator ground clips a little tighter?

    Best regards,

    Sean