Patent ID: 7106123

Claim:
A semiconductor device comprising: a first circuit which operates on a first voltage of power supply and outputs a first signal with the amplitude of the first voltage of power supply; a second circuit which operates a second voltage of power supply higher than the first voltage of power supply; and a level converter which operates on the first and second voltages of power supply, converts said first signal to a second signal with the amplitude of said second voltage of power supply, and outputs the second signal to said second circuit, wherein said level converter includes a signal-level shifting block including MOSFETs of a first gate oxide film thickness and a signal-level determination block including MOSFETs of a second gate oxide film thickness which is thicker than the first gate oxide film thickness, said signal-level shifting block generates a third signal that shifts between said second voltage of power supply and said second voltage less said first voltage by boosting the voltage level of said first signal through a capacitor and a signal of inversion of the level of said first voltage of power supply by inverting said first signal; said signal-level determination block includes an n-channel MOSFET and a p-channel MOSFET of said second gate oxide film thickness and connected in series to a ground potential and said second voltage of power supply, level determination is performed by inputting said signal of inversion of the level of said first voltage of power supply to the gate of said n-channel MOSFET and said third signal to the gate of said p-channel MOSFET.