UCC28070: What does "Dbypass" do?

Jeon Eun Bin

Part Number: UCC28070

Tool/software:

Hello.
I'm trying to make a 4kW PFC using UCC28070.

I don't know the function of DB in the image.
Is there a reason why you use it?
If necessary, should the IF value be designed based on the maximum load current amount?

3 months ago

+1 Ulrich Goerke 3 months ago

TI__Mastermind 40530 points

Hello Jeon,

Please refer to this previous E2E on the topic: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1077117/ucc28060-what-is-the-role-of-the-bypass-diode

The bypass diode is common to all non-isolated boost-PFC designs, and is independent of the controller.
This diode should be rated to carry the peak inrush current reliably.
It should be a standard recovery diode (not fast recovery) to have a lower forward voltage drop than the boost diode.

Regards,
Ulrich

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UCC28070: What does "Dbypass" do?