Patent ID: 7304502

Claim:
A level shifter comprising: a first transistor electrically coupled between an output terminal and a first voltage source supplying a first voltage for applying the first voltage to the output terminal in correspondence with a first input signal applied to a gate electrode of the first transistor; a second transistor electrically coupled between the output terminal and a second voltage source supplying a second voltage for applying the second voltage to the output terminal in correspondence with a voltage applied between gate and source electrodes thereof; a third transistor electrically coupled between the gate and source electrodes of the second transistor for lowering the voltage applied between the gate and source electrodes of the second transistor to zero in correspondence with the first input signal applied to a gate electrode of the third transistor; a fourth transistor electrically coupled between the gate electrode of the second transistor and the second voltage supply for turning on the second transistor in correspondence with a second input signal applied to a gate electrode of the fourth transistor; and a capacitor electrically coupled between the gate and source electrodes of the second transistor to keep the voltage applied between the gate and source electrodes of the second transistor to turn on the second transistor when the fourth transistor is turned off in correspondence with the second input signal.