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UCD3020: ucd3138

Part Number: UCD3020
Other Parts Discussed in Thread: TINA-TI, UCD3138

Do you see any problem in implementing a different PFC power stage based around the PFC example UCD 3138 has?

  • I do not expect any problems.

    But of course this is a very open and generic question.

    To be sure, you can send your power stage simplified schematic and the required switching waveforms.

    Regards,

  • Yitzhak
    You guys impress me by very prompt replies!

    In what form can I send you the power stage?
    TINA-TI screen shot?
  • You may sent it to my email address:
    y-bolurian@ti.com
  • Yzhak:

    the email address you typed did not work. It bounced right away.

    but see attached herewith. 3  jpg files.

    ----------------------------------------------------------- what I wrote in the email-----------------------------------------

    Yitzhak

    Per your request, pl see attached jpeg files of  the power stage, simulation waveforms.

    Notice linear portion of the inductor current. 

    So it is not different from typical boost.

    What is different is a short time duration when all state variables (iL, Vc) go to 0. & of course the negative  discharge currents. 

    For this power stage to give PFC, this "0" state is essential.

    So we have to build this duration in the state machine.

    Notice how well line current attains steady state after a few line cycles.

    Now that you see the power stage & its waveforms, I would appreciate your thinking on how to implement full PFC with control using UCD3138.

    For good control, we plan to change both duty & frequency (only in transient response)

    This PFC must have a wide bandwidth for x-over frequency due to fast transient response.

    I will like to model it using  any TI analog controller chip so that we know its closed loop behavior very well.

    Notice minimal EMI filter.

    Which controller do you suggest I can try?

    It would be essential to design a very correct input filter . Is that possible through modeling in TINA-TI or web-bench?

    thnx  for your help

  • Even though you showed the schematic and waveform, it is still not clear how the converter works, we have never done something like this before. Since it is a new topology, please contact TI local FAEs to get help. It is not easy to discuss this kind of question through E2E. If you have any specific question regarding UCD, for example, if you know the PWM waveform to control this topology but not sure if UCD can generate such waveform, then we can help you at here.

  • Bosheng

    Thanks for the comments.

    I will contact local FAE