Patent ID: 7492206

Claim:
A level shifter adapted to generate an output signal having a swing voltage shifted by a positive boost voltage with respect to an input signal, and comprising: an enable unit adapted to enable the output signal in response to the input signal, and a disable unit adapted to disable the output signal in response to the input signal; wherein the enable unit comprises: a shifting voltage terminal adapted to receive the boost voltage; a control node; a shifting unit disposed between the shifting voltage terminal and the control node and responsive to the output signal, such that a voltage having a difference with the boost voltage lower than a voltage of the output signal is provided to the control node, whereby the output signal is boosted by the positive boost voltage; a control PMOS transistor disposed between the control node and the output signal and gated by the input signal; and a bulk voltage generation unit receiving the boost voltage through the shifting voltage terminal and a voltage apparent at the control node, and generating a predetermined bulk voltage having a voltage level higher than the voltage apparent at the control node when the output signal is disabled, and applying the predetermined bulk voltage to a bulk of the control PMOS transistor.