I have an EclipsPlus flop running off 3.3 volts and want to drive the gate of a phemt with minimum delay. The flop swings just enough, 0.8 volts p-p, but the DC level is a volt or so below 3.3, so I have to shift it down. The ideal gate voltages are about +0.1 (on, slightly enhanced) and -0.7, off.
I considered this...
which is simple but it has to be tweaked, and the gate voltage will still track any drift on the 3.3 volt supply.
This
has a split path: fast AC coupling into the gate, then a slow opamp-based DC path. The opamp is a diffamp, so mostly ignores the value of the 3.3 volt supply.
Maybe it should have explicit lowpass filtering in the diffamp, to make sure the opamp properly averages the differential pecl voltage.
Any other ideas?