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UCC28019A: Ripple factor of input capacitor.

Part Number: UCC28019A


Current oscillation occurs at AC100V / above 550W.

My customer wants to design a 700W system.

My customer said it was not coil saturation.
Which part value should be adjusted?

And the ripple factor in the input capacitor is usually 0.2?


  • Hi David,

    I have assigned this thread to product expert. He should be able to respond within 2 business days.


    Manikanta P

  • Hi David,

    Thank you for the query.

    If it is not inductor saturation we will have to check a couple of things:

    1. Ensure that the inductor current ripple factor is less than 0.4. Can you please share the excel calculator which the customer used for design or the schematic?

    2. Rsense might have to be lowered. ICOMP pin is most likely getting saturated at the peak of the input line voltage. The internal amplifier has a linear range only upto 5.6V (I think) and after which it is non linear upto 7V. So duty cycle might be irregular as compared to linear range which will result in distortion. The only way to prevent this saturation is by reducing the current sense resistor which lower the value of ICOMP.

    Please let us know if you have any questions.