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PFC totem pole or just plain old PFC for 400W

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Advanced Member level 5
Jun 13, 2021
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We are up for an offline PSU for 100-265VAC.
No-load-to-full-load transient will be very common.
Peak power is 400W.
Average power something like 50-250W.

(the downstream stage is wanted to be LLC)

At this power level....Is it really going to save that much doing a full totem pole PFC?...IE, with two GaN FETs and two SiC FETs.
They want it in a totally enclosed plastic enclosure.

Bridge rectifiers are tough...i reckon a bridge rectifier on a decent chunk of aluminium (with a plain old Boost PFC) might be just as small a solution as the totem pole PFC one?
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Certainly the following tells that totem pole PFC with WBG devices gives just as big magnetics as plain old PFC...

I am just wondering that at 400W peak/ 250W average power, we would end up being nore efficient and small with a plain old BCM boost PFC?
I mean, the digital controllers needed for Totem pole PFC probably consume some 2W of power by themselves?
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I dont see any totem pole PFCs with analog controllers....all micro controlled.....which means much bias power.
I reckon these 300W all-in-plastic chargers using totem pole PFC are all marketing hype?
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Ive just searched for the datasheet for the NCP1680 CrCM Totem pole PFC controller, and you cant get it.....unless you email the this because they dont want people knowing about any high bias power draw that it may (or may not) have?
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Page one of this says there are no analog controllers available for totem pole PFC as at 2017
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Just wondering, at power levels of 300W or so, it may be more efficient to just go for a simple BCM Boost PFC, and make the bottom two diodes of the rectifier bridge synchronous?...that would be simple to do, because they are referenced to primary ground.

..And here we have says for 300W applications, Plain old BCM Boost PFC , and totem pole PFC, have the same losses...

Where do you say the "power pivot point" is?
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