TPS54627: whistling when using dynamic load

Hi, What's you dynamic loading frequency?

Yuchang

I try the frequency from 1K、6K、10K using electronic load, I hear the different whistling.

Seems It should be related to the loading transient frequency, which is in audio frequency area 20-20kHz.

Did you confirm the whistling was from inductor or the output caps?

Please upload you schematic for review.

Yuchang

TPS54627_yuanlitu.pdf

Sch as attachment.

I'm not sure the whistling is from inductor or  outpue cap. It seems the whisting is from IC.

I try the tantalum capacitors and Electrolytic caps as output caps , whistling  is a little  smaller than before.but I can  hear it.

And  we also change the inductor to 3.3uH and 4.7uH, the same phenomenon.

We try the IC TLV62130, the samen dynamic loader,Also has the whistling. we try the TI TLV62130-EVM board,the same whistling

It  strongly related to the loading transient frequency

Yes, it is related with loading frequency as I said.

Based on you test result, I suppose the whistling comes from input MLCC, IC does not generate the audio noise, you can change input caps to pos-cap or tan-cap to check.

Yuchang

Do  the sch have  any problem?