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UCC28019: Abnormal Waveform @110VAC Input

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Replies: 1

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Part Number: UCC28019

Hi Team,

   My customer is use ucc28019, when test under 220VAC input, everything is OK. But when the input voltage 110V, output up & bottom are oscillation, as below.

  

Customer refer to PMP2552, and do some small change, SCH is as below:

How to modify to reduce the oscillation?

Thanks and Regards,

Holly

  • Hello Holly,

    Thank you for your interest in the UCC28019 PFC controller.

    The oscillations at the + and - peaks of the input current are the result of operating at current limit of the PFC stage.
    The PMP2552 reference design is valid for input voltages from 185Vac to 265Vac, in other words: it is high-line only.
    It was not designed to handle low-line conditions.

    At 110Vac input, the peak currents are higher than the current limit set point, so the controller limits the switching peaks on a cycle-by-cycle basis.
    That is the cause of the oscillations.  Simply reducing the current sense resistors is not a solution because the inductor and the output capacitance are not sized for the higher peak currents at the minimum input voltage that the customer wants to apply.

    I recommend that the customer use the UCC28019A Excel Design Calculator Tool to generate a new design using the appropriate input conditions for his application.
    I also recommend changing from UCC28019 to the UCC28019A, which is a drop-in replacement and has some functional improvements.  But UCC28019 can still be used, if desired.

    Regards,
    Ulrich

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