Paired N-channel MOSFETs
The Bi-directional Switch Commutation Issues
-Fig.3.1 Possible discrete implementations of a bi-directional switch.
Fast switching / low turn-off time / inverter grade / MOS-gated thyristors have turn off times of 5us to 30us, but are expensive or made for high current applications.
Turn-on time is typically 2 us.
Apparently kHz switching is reasonable, not clear how high it can go with common parts.
Motorola – Thyristor device data TRIACs SCRs Surge Suppressors
-describes matrix switching
Thyristors & Triacs – Ten Golden Rules for Success In Your Application
ST APPLICATION NOTE: NEW TRIACS: IS THE SNUBBER CIRCUIT NECESSARY?
Logic level and sensitive gate triacs
Solid State AC Relays Using Triacs
ON Thyristor Theory and Design Considerations Handbook
Phototriac dV/dt Application Note
IRFR120N hexfet, 9A 100V ($0.29 / 100)
Guide to using optocouplers
-Tie transistor base to ground (1M to 47k ohm resistor) to speed up switching.
High and low side driver, IR2110S, 500V, 2A, $1.00 / 1