WEBENCH® Tools/TPS53355: TPS53355 Output ringing

boer.deng

Part Number: TPS53355

Tool/software: WEBENCH® Design Tools

According to the design of WEBENCH, 12V was input and output was 0.9v / 23.4a. The load was CPU, and the output was ringing, Rr=105K and Cr= 6.8nf.How can you eliminate ringing?thank you

over 5 years ago

0 JohnTucker over 5 years ago

TI__Guru**** 191445 points

Boer,

Can you provide a waveform showing both LL and Vout?

0 boer.deng over 5 years ago in reply to JohnTucker

Expert 1085 points

You hope to help analyze;The last diagram is the output of LL；What else do we need to measure?thank you

0 JohnTucker over 5 years ago in reply to boer.deng

TI__Guru**** 191445 points

Boer,

First let me comment on your test method. You can not use long ground leads with your probes to accurately measure these waveforms. The ground lead should be less than 1 cm (use a wire pig tail) or better yet, use the "tip and barrel" method. Measure directly across the HF bypass capacitor on your output filter. You may need to add some additional 0.01uF and 0.001uf ceramic as well. Make sure to populate C65 and R61 snubber circuit. Those initial values look good, but you may need to fine tune it. I use this document:

7510.RC Snubber.pdf

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WEBENCH® Tools/TPS53355: TPS53355 Output ringing