TPS23754: Vout waveform abnormal when light load & normal load

Kay Chen53

Part Number: TPS23754
Other Parts Discussed in Thread: PMP6812

Hi there:

our customer currently have an issue about the Vout waveform strange when light load and normal load. (Vin 48V and Vout 10.4V)

The following is their schematic and test result, we'd like to need your help to provide some suggestion that we could have customer to check firstly.

schematic

TPS23754 _10.4V.pdf

test result when loading at 0.1A & 2.1A

over 6 years ago

0 Darwin Fernandez over 6 years ago

TI__Mastermind 40720 points

Hi Kay,

This might be the feedback circuit. I recommend using the "A" version of the EL357. The current looks high through the opto as well as we typically will design with 2k for R275 and R278.
Any particular reason these were changed from PMP6812 as it looks like it was derived from this working TI Design?

Thanks!

Regards,
Darwin

0 Thomas Lewis over 6 years ago in reply to Darwin Fernandez

TI__Expert 5615 points

Hello Kay. It has been over a week since we last heard from you? Is this matter still requiring our support?

If we have not heard back from you by 9/28, I am planning to close this thread.

Please let us know if requiring anything further,

0 Kay Chen53 over 6 years ago in reply to Thomas Lewis

Expert 2225 points

Hi Thomas:

Thanks again for your sharing. currently customer side has no further feedback.

Still many thanks from your suggestion.

Power management

Power management forum

TPS23754: Vout waveform abnormal when light load & normal load