TPS54428: There is a drop in Vout while start up progress

Troyson Li

Part Number: TPS54428

Hi Team,

My customer found there is a drop in Vout while start up progress whatever the load is light or heavy. Can you help to clarify why the phenomenon happens?

Ps .

1 . The picture-1 is their .SCH

2. The picture-2 is the waveform in failures.

over 4 years ago

0 JohnTucker over 4 years ago

TI__Guru**** 191445 points

Troyson,

Can you zoom in on that transient? Can you also show the inductor current during that time?

0 Troyson Li over 4 years ago in reply to JohnTucker

Expert 2475 points

Hi JohnTucker,

Please see the picture after zooming. And customer does not do the inductor current test .

0 JohnTucker over 4 years ago in reply to Troyson Li

TI__Guru**** 191445 points

Troyson,

It looks like there is a load transient during the start up. Without seeing the current profile it is not possible to tell. If they cannot measure the current can they disconnect the load and check the start up?

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TPS54428: There is a drop in Vout while start up progress