Patent ID: 8536905

Claim:
A level shift circuit comprising: a level shift voltage generation circuit that receives an input signal having an amplitude between a voltage of a first voltage system power supply and a ground potential and performs a conversion of the amplitude of the input signal to produce an output signal voltage with an amplitude between a voltage of a second voltage system power supply and the ground potential, the voltage of the second voltage system power supply being higher than the voltage of the first voltage system power supply; a replica circuit that comprises an element having a same configuration as an element of the level shift voltage generation circuit, the replica circuit monitoring a voltage corresponding a logic threshold of the first voltage system power supply, the replica circuit, with the logic threshold of the first voltage system power supply as an input, monitoring and outputting a voltage corresponding to a logic threshold of the second voltage system power supply; and a bias generation circuit that receives an output from the replica circuit and generates a bias for adjusting a variation of the output signal voltage of the level shift voltage generation circuit and a variation of the output voltage of the replica circuit to supply the bias to the level shift voltage generation circuit and the replica circuit, wherein the level shift voltage generation circuit generates the output signal voltage in such a manner that, at a time when a voltage of the input signal received by the level shift voltage generation circuit crosses the logic threshold of the first voltage system power supply the output signal voltage crosses the logic threshold of the second voltage system power supply, and wherein the bias generation circuit comprises a comparator circuit that compares an output of the second voltage system of the replica circuit with the logic threshold voltage of the second voltage system outputted from the replica circuit.