So since the Boost PFC diode will never see inrush (when inrush is bypassed as discussed), then why are BCM Boost PFC controllers so popular?
I mean, BCM Boost PFCs need an extra winding in the Boost inductor….why bother with this faff when you can just do CCM Boost PFC instead? Another point is that BCM Boost PFC’s suffer from very high frequency operation when on light load…this results in unnecessarily high switching losses, since BCM Boost PFC’s do nothing to help turn-OFF switching losses….
Also, when the load lightens, BCM Boost PFCs get more noisy and loose PFC operation quicker than CCM PFC’s…this is because the signal from the “signal” winding on the BCM Boost inductor gets very oscillatory and so the zero crossing point is often not distinct enough to be picked out by the ZCD comparator.
All this is a big downer for BCM Boost PFC.
So why do it?..why not CCM Boost PFC instead?