UCC28180: buck configuration UCC28180 load response

Archie Magsombol

Part Number: UCC28180

Hi TI,

Im currently working on a 1kwatt buck PFC using UCC28180. It works well as step down converter on no load, but I notice at small load 1A (loaded on it DCDC side) dips instanly the output voltage (see image). Can you help me pls or advise how to improve the load response for this type of buck configuration for UCC28180. Thank you. Screenshot 2025-11-05 105303.png

3 months ago

0 Sanchayan Das 3 months ago

TI__Intellectual 1465 points

Hi Archie,
UCC28180 is a boost PFC controller it might not work properly for a buck PFC. Form the waveform it looks like your compensator is not reacting fast enough to the transient load. You can try to increase the compensator bandwidth, but it is recommended to keep the bandwidth around 1/5th of line frequency for better THD. If you increase the bandwidth of your compensator your THD will start to degrade, and your input current shape will start to deform.
Thanks
Sanchayan

0 Archie Magsombol 3 months ago in reply to Sanchayan Das

Prodigy 30 points

Hi Sanchayan Das,

Thanks a lot for the info. I'll take note of this as we go along.

Regards,

Archie

0 Sanchayan Das 3 months ago in reply to Archie Magsombol

TI__Intellectual 1465 points

Hi Archie,
I will close this tread for now. Feel free to open a new thread if you have any other query.
Thanks
Sanchayan

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UCC28180: buck configuration UCC28180 load response