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UCC28063: UCC28063 field site damage

Part Number: UCC28063

Hi,

My customer use UCC28063 for PFC control in monitor.

They have field site failure with 1/1000 failure rate. The failure symptom is pin 11, 12 short to ground. They also have similar design on other model but no failure.

I think that it may be due to layout issue.

Can someone help review the layout and design?

BR,

frank

  • Hi Frank,

    thanks for your interest in UCC28063.

    Pin 12 is the VCC, Pin 11 is the GDB.

    I suggest to confirm whether at some condition those two pins has over voltage stress, especially GDB pin.

    if you use different mosfet for this project, I would also suggest whether the failure always caused by one mosfet factory。

  • hi David,

    due to failure rate is very low, I cannot measure the voltage at failed condition.

    for normal condition, the waveform looks good.

    for the mos, the ok model and issued model uses the same mos, IPA60R080P7 .

    any other idea?

    BR,

    frank

  • Hi Frank,

    I would suggest to check if there is ringing on the GDB pin at the turn-on or turn-off edge. The ringing may be very brief and cannot be seen if you have a bandwidth filter on the probe measurement. If this is happening, typically a larger gate resistance can help dampen gate ringing.

    Best Regards,

    Ben Lough

  • hi Ben,

    I measure the GDB pin. At light load or heavy load to light load, there is a peak on GDB pin as waveform below.

    from spec, "Continuous input voltage range for GDB is -0.5 - Vcc+0.3V.

    the Vcc is 16V. For this condition, is there any concern?

    BR,

    frank

  • Hi Frank,

    I do not expect this kind of waveform will damage the controller. You can compare the VCC together to see whether VCC is constant at 16V.

    I suggest you can probe any working condition that may be worse than the condition you probed in the post to see any new find.

    I supported a customer that has a negative voltage on the output pulse pin that also let the controller fail.