TPS54336A: TPS54336A is question about phenomenon occurs that the switching pulse disappears.

Bob Lee62837

Mastermind 7230 points

Part Number: TPS54336A

Dear support member,

My customer used TPS54336A.

I have a question.

The phenomenon occurs that the switching pulse disappears just before the output voltage rise.

What kind of principle is this behavior like?

Is there no problem in behavior?

I have attachedfile about schematic and waveform.

Could you check attachedfile?

Best regard.
Bob Lee.

TPS43336A_Question_180202.pdf

over 7 years ago

0 Jason Wang (BSR-MV) over 7 years ago

TI__Genius 9550 points

Bob,

I am going to look into this and get back to you on Monday.

0 Vental Mao over 7 years ago

TI__Expert 5745 points

This is the eco-mode. When the peak switch current is lower than 0.5 A (typical), the device stops switching to boost the efficiency until the peak switch current again rises higher than 0.5 A (typical).
so if your load is more than 0.5A before start-up, there will be no such valley. You calso can refer to Figure 49 in DS, it's similar to your waveform.
it's not an issue

0 Bob Lee62837 over 7 years ago in reply to Vental Mao

Mastermind 7230 points

Dear Vental Mao,

Thank you very much for reply.

May I ask a question?
This Eco-Mode did not operate during the soft start period,
Is it no problem?

Best regard.
Bob Lee.

0 Vental Mao over 7 years ago in reply to Bob Lee62837

TI__Expert 5745 points

It's not a problem.

During soft start period, the Eco-mode doesn't enable.

Power management

Power management forum

TPS54336A: TPS54336A is question about phenomenon occurs that the switching pulse disappears.