Interleaved Boost PFC datasheet (UCC28070)

[treez]

Maximum duty cycle for Boost PFC stage?

Hello,
We wish to set the maximum duty cycle of our 45khz boost pfc stage to 0.9. The controller is UCC28070.
Do you believe we will get problems from this.? We don't want it too high or else the current sense transformer reset voltage gets too high.

UCC28070 datasheet
https://www.ti.com/lit/ds/symlink/ucc28070.pdf

 

[D.A.(Tony)Stewart]

Re: Maximum duty cycle for Boost PFC stage?

interleaved cancellation degrades away from 50% d.f. so the size of core must be increased to avoid saturation of boost inductors.

 

[treez]

Hello,
Do you know what is meant by the "nominal, zero bias boost inductance (uH)" referred to on page 21 of the UCC28070 datasheet (equation 12)

UCC28070 datasheet
https://www.ti.com/lit/ds/symlink/ucc28070.pdf