Patent ID: 8542051

Claim:
A level shift circuit comprising: a level conversion unit that converts an input signal having a signal level of a first voltage into a signal having a signal level of a second voltage that is higher than the first voltage, wherein the level conversion unit includes first and second MOS transistors of a first conductivity type and third and fourth MOS transistors of a second conductivity type, which differs from the first conductivity type and of which switching is controlled in accordance with the input signal, the third and fourth MOS transistors include drains supplied with the second voltage via the first and second MOS transistors, respectively; and a control unit coupled to a back gate of each of the third and fourth MOS transistors of the level conversion unit to apply a body bias to the back gates of the third and fourth MOS transistors, wherein the control unit, when receiving a detection signal indicating a decrease in the first voltage, controls a voltage value of the body bias applied to the third and fourth MOS transistors to decrease a threshold voltage of the third and fourth MOS transistors.