A simple demonstration of a bidirectional
or reverse-blocking high side power switch
using a back-to-back series connected pair
of P channel MOSFETs.
In this configuration, both MOSFETs are
switched on or off together. When off,
the back-to-back connection means that
reverse conduction through the body diode
of M3 is blocked by the body diode of M2
and vice versa.