WEBENCH® Tools/TPS54361: noise/oscillation on the output

user3453450

Part Number: TPS54361

Tool/software: WEBENCH® Design Tools

Dear friends

I got a design from WEBENCH with TPS54361DPR . While finally after we received the board . We found there are large amplitude of noise or oscillation at the output.

How can I depress the amplitude of AC (noise or oscillations ...etc ) part to less than 50mV or even smaller ?

Here are the relevant pictures, Please give me some tips about fixing it .

Below 4 pictures are the output wave of TPS54361DPR which are AC coupled .

Below is the schematic .

over 5 years ago

0 user3453450 over 5 years ago

Intellectual 280 points

Above is another picture at the output ,

Thank you .

0 Iven Su over 5 years ago in reply to user3453450

TI__Expert 8245 points

Hi,

Please add a 1uF capacitor in the output, thanks.

0 user3453450 over 5 years ago in reply to Iven Su

Intellectual 280 points

Hey Iven

Thank you .

I just tried as you said , But it didn't work .

There were no explicit change at the out .

Kind regards

Anglic

0 user3453450 over 5 years ago in reply to Iven Su

Intellectual 280 points

hey Iven

Also , the glitch appears in a frequency of 29Hz or so as we can see from the picture , overlapped by some high frequencies .

Thank you

Anglic

0 Iven Su over 5 years ago in reply to user3453450

TI__Expert 8245 points

Hi,

Could you please also show the SW node waveforms, it looks the loop is not very stable.

0 user3453450 over 5 years ago in reply to Iven Su

Intellectual 280 points

hey Iven

Here are the pictures at the SW node ,

Whereas , I have already replaced the C9 with a 100uF/100V Aluminum Electrolytic Capacitor .

Is it stable?

Best Regards

Anglic

0 Iven Su over 5 years ago in reply to user3453450

TI__Expert 8245 points

Hi,

It looks it's no load waveform, please check if you got rectangular waveform with some load. Thanks.

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WEBENCH® Tools/TPS54361: noise/oscillation on the output