Patent ID: 7659767

Claim:
A level shifter, comprising: a first boost circuit for receiving an input signal and determining a first amplification factor of the input signal based on a control signal, wherein the first boost circuit is powered by a first voltage source, and the first amplification factor of the input signal is dependent on the voltage level of the first voltage source; a first inverter for receiving the input signal to generate an inverted input signal; a second boost circuit coupled to an output terminal of the inverter to receive the inverted input signal and to determine a second amplification factor of the inverted input signal based on the control signal, wherein the second boost circuit is powered by the first voltage source, and the second amplification factor is dependent on the voltage level of the first voltage source; and a level shift circuit powered by a second voltage source with the voltage level higher than that of the first voltage source, wherein the level shift circuit has a first input terminal and a second input terminal respectively coupled to output terminals of the first boost circuit and second boost circuit to generate an output signal according to output signals from the first boost circuit and second boost circuit, wherein a level shift of the output of the level shift circuit is dependent on the first voltage source and the second voltage source.