UCC28065: VDS waveform not stable and cause noise when enter current limit

Anderson Cheng

Part Number: UCC28065
Other Parts Discussed in Thread: UCC28064

Hi Experts,

Customer test on UCC28065 EVM(modify from UCC28064 EVM).

input is 90Vac, found when reach current limit, the VDS wave form is not stable and cause noise, can you help to analyze the problem and provide improve solution.

Thanks.

Anderson

over 3 years ago

0 Ray DiCecco over 3 years ago

TI__Genius 11350 points

Hi Anderson,

This appears to be zero-crossing distortion which is common in PFC (but pretty severe in your case). Please try reducing the capacitance placed just after the bridge. It adds non-linearity to the circuit. If this doesn't improve the distortion enough, if you share your schematic and design calculator (www.ti.com/.../sluc697), I'd be happy to make suggestions.

Regards,
Ray

0 Ray DiCecco over 3 years ago in reply to Ray DiCecco

TI__Genius 11350 points

Hi Anderson,

I haven't heard back, so I assume the problem has been resolved. If not, feel free to open a new thread.

Regards,

Ray

0 Anderson Cheng over 3 years ago in reply to Ray DiCecco

TI__Intellectual 1270 points

Hi Ray,

thanks for your support, I have reached out with AE David for help directly.

0 Ray DiCecco over 3 years ago in reply to Anderson Cheng

TI__Genius 11350 points

OK, I will close this out. If you or David need any assistance, feel free to reach out.

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UCC28065: VDS waveform not stable and cause noise when enter current limit