• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 452 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

UCC28070: PFC has a low PF value

dushimutong
Intellectual 620 points
Part Number: UCC28070

Hello

PFC PF value is low, what is the reason?
How to debug?
What are the possible reasons?
Input 220VAC, rated output 360VDC, load 510 ohms, PF value 0.55, output 340VDC.

Thank you

Regards

Neil

  • 0
    TI__Genius 9130 points
    Neil,

    I will ask an application engineer from the relevant team to look into your issues.

    Meanwhile, can you give more details to help?

    Can you post your schematic (with values) and some waveforms? The line current, output voltage, PFC gate drive and PFC CS.

    It sounds like the PFC controller is not running for some reason and you are just get peak-rectifed AC with resulting very poor PF.


    Thanks,
    Bernard
  • 0 in reply to Bernard Keogh
    Intellectual 620 points

    Hello,Bernard

    Thank you very much.

    PFC inductance for the ferrite EE55, 33 turns, 120uH


    Output capacitance 1880uF
    With 250W load, PF value of 0.55, the output voltage dropped to 340V。
    CSA waveform
    AC input current waveform