UCC28881: Light-load

ACGUY

Guru 11170 points

Part Number: UCC28881

Hello E2E,

When light-load opperation onDCM, the switching frequency is not constant. The inductor makes a sound.

Vin : DC350V - DC400V
Vout : 15V
Iout : 50mA(max)

L=3mH

Does it can solve? Or is it normally?

Regards,
ACGUY

over 4 years ago

0 Jaden Ning over 4 years ago

TI__Expert 7080 points

Hi ACGUY,

UCC28881 operates under on/off control , the switching frequency is not a constant. it might entry audible noise range . here is a application note which guide how to mitigate the audible noise , hope it can help you.

UCC28880, UCC28881 Audible Noise Reduction Techniques

Thanks.

Power management

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UCC28881: Light-load