Am I allowed to be totally lazy and make a post here without checking Google, news archieves, IC manufacture sites or even looking at mousers or digikeys websites? :) Exploitive or Efficient? Anyways...
I'm looking for a smps controller and it would be nice to dodge the supply design for powering the controller IC.. I'm aware of some controllers that run off up to 200VDC. But I seem to be finding many 12V to 20V controllers.. Why is that? Are they generally better than offline powered ICs?
I just starting searching and found the LT1738..Looks good..Just wish it ran off 170DC and not 12V. Even if this IC had an internal linear regulator that could take on 170DC in, the max current draw is 40mA resulting in a ouch hot IC.. A low current controller (say CMOS) will have a cooler internal regulator but I've associated lower current with low speed. So maybe this is why offline powered chips are hard to find..
Any IC suggestions or favorite manufactures with offline controllers?
IC requirements: (Non-absolute)
100khz Internal Mosfet driver Current feedback off load Suitable for Cuk Topology IC runs off 170VDC PWM