Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 64 subscribers
  • Views 82 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC28065: About High switching frequency(Higher than 500kHz) PFC IC, but don't need interleaving.

?? ?
Prodigy 90 points
Part Number: UCC28065
Other Parts Discussed in Thread: UC2854A

Tool/software:

Hi team,

I wanna ask if I use UCC28065 as a PFC converter, can I just use one output.

I don't need interleaving and transition mode,but need high switching. Or you have others recommend PFC IC? 

  • +1
    TI__Mastermind 32390 points

    Hello, 

    The way the UCC28065 PFC controller is designed, it can operate long term with one one phase (channel, output) running and the other one not running, however, it always drives both phases at start-up to avoid the risk of CCM in the inductor.  This is explained at the bottom of page 19 in the UCC28065 datasheet.
    If you are driving only one channel (Phase-A), then the gate pulses for Phase-B will have no effect, but the IC will behave as it is designed for 2-channel operation. 
    You will have to accommodate this behavior in your design. 

    The UCC28065 is designed to operate in transition mode.  It cannot operate in any other mode.  The high frequency range at which it is capable of operating is normally the result of light load and high-line input voltage.  Lower frequencies (usually much lower) can be expected at low-line and higher loads.     

    If you want a PFC converter to operate at >500kHz all the time, you will need a fixed-frequency controller.  Most such controllers are CC-PFC and most of TI's more recent CCM-PFC controllers have frequceny limits around 300kHz or less. 
    However, the UC2854A PFC controller can be programmed to switch up to about 800kHz.  This is a much older device made in a Bipolar process (UC prefix, not UCC which is BiCMOS) but it is still available and meets your frequency requirement.  Application notes to use this device can be found on the UC2854A product page, and some app-notes on theUC2854 page also apply to the UC2854A.   https://www.ti.com/product/UC2854A#tech-docs  and  https://www.ti.com/product/UC2854#tech-docs 

    Regards,
    Ulrich