Sensitive thyristor having improved noise-capability.

摘要

A MOSFET (19) is provided between a main thyristor (26) and an auxiliary thyristor (27) for controlling the main thyristor (26). The source and drain regions of the MOSFET (19) are also used as a first N-type emitter region (16) of the main thyristor (26) and a second N-type emitter region (18) of the auxiliary thyristor (27). The MOSFET (19) and the auxiliary thyristor (27) are controlled by an output of a gate energization circuit. When the MOSFET (19) is turned on by an output of the gate energization circuit, the main thyristor (26) is connected to the auxiliary thyristor (27). At this time, the auxiliary thyristor (27) is turned on by the output of the gate energization circuit, and the main thyristor (26) is also turned on due to the turn-on operation of the auxiliary thyristor (27). When the MOSFET (19) is in the OFF state, the main thyristor (26) is electrically isolated from the auxiliary thyristor (27).