Patent ID: 7782114

Claim:
A voltage level shifter circuit comprising: a first power supply adapted to provide a first supply voltage; a second power supply adapted to provide a second supply voltage different from said first supply voltage; an input terminal adapted to receive a first signal generated using said first supply voltage; an output terminal adapted to output a second signal representative of said first signal and generated using said second supply voltage; a voltage adjusting circuit connected between said input terminal and said output terminal and adapted to pull said first signal from said first supply voltage to said second supply voltage; and a pair of series connected switches connected between said input terminal and said voltage adjusting circuit, wherein said pair comprises a first switch controlled by said first power supply and a second switch controlled by said second power supply such that only when said first supply voltage from said first power supply reaches said first switch and said second supply voltage from said second power supply reaches said second switch will said first signal pass to said voltage adjusting circuit.