Patent ID: 8384124

Claim:
A semiconductor device having an electrostatic surge protective circuit formed between a first power supply wire and a ground wire, comprising: an output circuit having an insulated gate bipolar transistor between the first power supply wire and an output terminal or between an output terminal and the ground wire; an insulated gate bipolar transistor between a potential of the first power supply wire and a potential of the ground wire; wherein a latch-up initiation voltage of the insulated gate bipolar transistor of the protective circuit is lower than that of the insulated gate bipolar transistor of the output circuit, wherein the insulated gate bipolar transistor in the protective circuit has a lower impurity density in a first conduction type region provided to prevent a latch-up operation than that in a first conduction type region provided to prevent a latch-up operation of the insulated gate bipolar transistor in the output circuit.