Optically triggered MOS gated solid state relay is a new switching device, which is composed of an MOS gated thyristor, a phototransistor, an enhanced mode MOSFET and a Zener diode.
Besides, in order to minimize the area of output driving MOSFET, high W/L density structure is adopted with effective W/L density being doubled compared with normal MOS structure.
The heart of its original embodiment was a metal-oxide-silicon sandwich , with initial letters responsible for the acronym MOS , as in MOSFET and MOS technology.