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BCM Boost PFC followed by 2 transistor forward with bootstrap high side drive. I am presuming it needs isolation, and that its Mains 230VAC input.
Or if you do not need isolation, then PFC'd Buck boost...this is very easy with led drivers......just do iterative-set-and-check current regulation.......give the input current a sine ref, and just shovel the output into the leds....theyll sort out their own voltage....adjust the peak of the sine ref to get the power you want.
Alternatively, again n'avec pas isolation.....BCM boost PFC, then Low side FET Buck. Have the led current sense in the hi side...so use eg hall sensor etc...or else just regulate the current peak, and calibrate it so you know what peak FET current gives roughly what power LEDs.
Also, you could use two PFC'd BCM flybacks at 75W each if you wanted.
There is also a famous and very well known Chinese circuit involving sequence switched linear regulators aswell. (its nowhere near as difficult as it sounds, and doesnt need a specific controller IC, just cheap OPamps)...its >85% efficient and PFC'd....but needs an extra LED module to handle >245VAC to 265VAC mains....this LED module is unfortunately unused if the mains is less than 245VAC.
.....Its a very very well known and used circuit, but every company that uses it thinks its their own IP.
Its fully dimmable and easy to dim.
Ive used it up to 250W.
It cant keep to max power over the full 100-265VAC range...but over some 210VAC to 265vac (With extra usually redundant led module, it can do max power)
It does need a micro if you want to make it well regulated, but the software for that is very very simple.
The circuit doesnt use any transformers, and is obviously not isolated. So It uses no custom components like transformers. It has a high degree of flicker though.....LED current actually turns off totally for some 500us or so at the mains zero crossing.
There are actually chips that do its method, but to be honest, you can do it better with opamps and a micro.
For somebody who was averse to using SMPS transformer based methods, it woudl be the way.