UCC28881: Non-isolated Buck circuit howling

Eric Fu1

Part Number: UCC28881

Dear Masters,

My customer design a 220V AC to 24V DC circuit based on UCC28881, and the circuit can work and output 24V normally, but they can hear howling when the circuit is operating. Could you please help to see where can we start to debug this issue? Below is the schematic for your review.

Thanks.

over 7 years ago

0 Ulrich Goerke over 7 years ago

TI__Mastermind 40350 points

Hello Eric,

First, I would ensure that the design was done following the design procedure in the datasheet or using the UCC28881 Design Calculator tool www.ti.com/.../getliterature.tsp .

Second, please refer to this debug app-note www.ti.com/.../slua821.pdf for tips on reducing noise in components. Usually, the magnetics can make noise if they are loosely constructed and/or unvarnished test units.

Regards,
Ulrich

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UCC28881: Non-isolated Buck circuit howling