• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 40 subscribers
  • Views 288 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.

PMP4478: startup load

Baskaran M
Prodigy 75 points
Part Number: PMP4478

If startup load is more than 250mA my power supply not working,But if increases from 0 to 3A it working fine

  • 0
    TI__Prodigy 480 points

    Hi Baskaran,

       Did you mean the power can start up below 250mA and then can work normally from 0 to 3 Amp, but can’t power on if load setting over 250mA?

       What is the failure mode you meet if power on with > 0.25Amp? Latch down or retry to auto recovery?

    Regards,

    Richard

  • 0 in reply to Richard Yin
    Prodigy 75 points

    Thank for ur response

    Did you mean the power can start up below 250mA and then can work normally from 0 to 3 Amp, but can’t power on if load setting over 250mA?

    Yes

      What is the failure mode you meet if power on with > 0.25Amp? Latch down or retry to auto recovery?

    Retrying to auto recovery (voltage vary from 0 to 2.5V like pulse )

  • 0 in reply to Baskaran M
    TI__Prodigy 480 points

    Hi Baskaran,

        This failure mode seems from the startup in VDD. Did you tried to increase the capacitance of VDD? If no, you can try to add a capacitor in parallel to C4.

    Do you have some waveform for this situation that can share with us? Because of we can clarify the root cause faster if we have more information.

    Regards,

    Richard

  • 0 in reply to Richard Yin
    Prodigy 75 points

    Hi,

              Thank for your response,once i added 10uF capacitor parallel to C4 upto 2A load its working,Right now the ripple is more on output how i can reduce further 

    Regards,

    M.Baskaran

  • 0 in reply to Baskaran M
    TI__Prodigy 480 points

    Hi,

      I think you can add more capacitor to output rail if the ripple is not under your specification.

    Regards,

    Richard