You could actually drive the EPC FETs from a 3.3V source
with only a trivial Ron penalty.
My EPC half bridge driver used an internal LDO (times two)
to ensure that the high side and low side devices saw the
same domain voltage, so consistent timing (shoot-through
control, not amenable to a lot of feedback at 80V common
mode offset, need fixed timing). And of course, to stay
well away from the 6V limit.
EPC is playing games with how they rate current on the
newer products. I called them out on it and got the
response that the rated current is pulsed peak, not
continuous.Caveat emptor. The current they rate is
simply not reliable (one solder ball, a hundred amps?
Not in this universe, unless you are force-cooled to
room temp. My regular customers aren't so lucky).
For hand built stuff the GaN Systems devices will be
a lot easier / more familiar to handle. But for ultimate
compaction, "no package" wins out.
Intersil / Renesas has just announced some co-packaged
EPC FETs and drivers (low side only as I make it out).
However the press release is aimed at the HiRel market
and Intersil is the kings of rape-the-customer pricing
in that segment. Maybe there's a plastic version that
is not insane, but I have not seen that announced. I'd
expect more in this vein from other vendors.