Part Number:UCC256301
In looking at the UCC256301, it appears that there is no way to turn off the X cap discharge if it is being powered from a DC source.
In another post, I see reference to some 'dash' versions of the part that might have this feature either disabled or selectable, but the answer there indicates that the UCC256301 is the only part that is released (no dash versions). Does TI have a similar part that doesn't have the X cap discharge (or has it as a selectable/programmable feature such that it could effectively be avoided?) We're expecting the DC to have relatively little ripple, so a capacitive coupling to a zero crossing sense pin may not be a reliable means of defeating the feature.
Thanks,
Chris
P.S. We're looking to have a very high efficiency (above 90%, preferably above 95%) Isolated HV DC to LV DC supply (approximately 300Vin, ~ 13Vout)
The input voltage suffers from poor line regulation at the light load end of the spectrum, possibly coming close doubling in value with zero load, so startup/OVP will have to be also considered/worked-around as well.