• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 365 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC28180: Input current waveform distortion and startup overshoot

Jack Deng
Expert 1090 points
Part Number: UCC28180

Hi Ti Guys

i used the UCC28180 in my 480W AC/DC project, but when the full load and input=220V,

 there are two problems that need your help, thx

1, Input current waveform distortion

2, startup overshoot

SCH as below:

  • 0
    TI__Mastermind 34465 points

    Hello Jack,

    You have an unusual arrangement of control on the VCOMP pin and it almost looks like this is somehow clamping the input current.

    I suggest that you disconnect all of this and use the Excel calculator tool in order to debug your circuit.

    The startup response is not that bad. The first plateau is due to the rectification of the input voltage which occurs before the pfc starts up.

    Then you get a small overshoot before the loop corrects itself. Is this happening at no load ?

    Regards

    John