Patent ID: 7746147

Claim:
A semiconductor device comprising: a level shifter circuit including an input part supplied with a first power supply and a level shifter part supplied with a second power supply, wherein said input part having inverter circuits include transistors connected to said first power supply and said inverter circuit having parasitic diodes formed inside thereof, and said level shifter part has transistors for input to which a first voltage signal is inputted from the outside through said inverter circuits, said level shifter part converting said first voltage signal to a second voltage signal higher in voltage than said first voltage signal depending on a condition of said transistors for input, and outputting said second voltage signal as an output signal to the outside; and circuits that generate a control signal to said transistors for input when said second power supply is inputted to said level shifter circuit before said first power supply, said second power supply being higher in voltage than said first power supply, wherein said circuits that generate the control signal have a current generating circuit including a current mirror circuit that applies a current to said first power supply in an off state connected to said inverter circuits through said parasitic diodes when said second power supply is inputted before said first power supply, and said circuits that generate the control signal further have a bias circuit connected between said current generating circuit and said inverter circuits for setting a voltage condition of the control signal of said transistors for input by receiving said current.