Patent ID: 6985023

Claim:
A semiconductor device comprising: a first transistor having a first conduction type first semiconductor region and a second conduction type second semiconductor region formed in the first semiconductor region, the first semiconductor region being supplied with a first prescribed potential, the second semiconductor region being supplied with a second prescribed potential; and a potential generator circuit generating the first prescribed potential, wherein; the potential generator circuit has a first power supply terminal supplied with a first power supply potential, a second power supply terminal supplied with a second power supply potential set to a higher potential than the first power supply potential, and an output terminal outputting the first prescribed potential, and the potential generator circuit outputs the second power supply potential as the first prescribed potential when the second power supply potential is higher than a predetermined potential, and outputs the first power supply potential as the first prescribed potential when the second power supply potential is lower than the predetermined potential, wherein the potential generator circuit comprises: a second transistor having a source connected to the second power supply terminal supplied with the second power supply potential, and a drain connected to the output terminal outputting the first prescribed potential; a third transistor having source and gate connected to the first power supply terminal supplied with the first power supply potential, and a drain connected to the output terminal outputting the first prescribed potential; and an inverter circuit having an input terminal connected to the second power supply terminal, and an output terminal connected to the gate of the second transistor.