Patent ID: 7649398

Claim:
A single input level shifter comprising: an intermediate voltage signal providing unit which provides an intermediate voltage signal having a voltage between a supply voltage and an input signal voltage; an inverting unit which receives the intermediate voltage signal and provides an inverted intermediate voltage signal; and a voltage signal comparing unit which compares the intermediate voltage signal with the inverted intermediate voltage signal and provides the supply voltage or ground voltage according to comparison between the intermediate voltage signal and the inverted intermediate voltage signal, wherein the voltage signal comparing unit comprises: a first PMOS transistor having a gate and a drain connected to the gate; a second PMOS transistor having a gate connected to the gate of the first PMOS transistor; a first NMOS transistor connected between the drain of the first PMOS transistor and an output node of the intermediate voltage signal providing unit and further having a gate connected to an output node of the inverting unit; and a second NMOS transistor connected between the drain of the second PMOS transistor and the output node of the inverting unit and further having a gate connected to the output node of the intermediate voltage signal providing unit.