TPS54061 noise

Witold Milarski89

Hi,

I have designed a 27VDC/3.3VDC PS. It appears to be working correctly but after having a closer look the output voltage does not look clean, which in turn appears to create problems in other parts of the circuit. Originally I designed it using Webench for 100mA, but the actual load ended up being ~30mA (with short 6ms bursts of additional ~20mA). I tried running it in the DCM as well. But the ringing is still there.

Any suggestions welcome.

Thanks

over 7 years ago

0 JohnTucker over 7 years ago

TI__Guru**** 191445 points

Can you post your schematic and layout? Also I would like to see both Vout and SW node waveform on the same screen at 2 usec/div.

0 Witold Milarski89 over 7 years ago in reply to JohnTucker

Prodigy 50 points

Hi John,

I wish I could respond earlier, but we are on completely opposite sides of the world.

Below is the information you requested:

The layout (if you would like the actual files I would like to keep them private):

By the SW node I assumed you meant the PH node for this chip. CH1-PH, CH-Vout, sorry no 2us/div option :(

Vout AC coupled:

and in case you need more detail:

Thanks

Witold.

0 JohnTucker over 7 years ago in reply to Witold Milarski89

TI__Guru**** 191445 points

I am getting ready to retire for the night. You can send me files at j-tucker(at)ti(dot) com. I start early (6 am) and may have some response shortly after that time.

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TPS54061 noise