LEVEL SHIFTER AND LEVEL SHIFTING METHOD INCLUDING MODE SELECTION FUNCTION

摘要

A level shifter having a mode selection function and a level shifting method are provided to operate some function blocks which are driven by using an output of the level shifter in a normal mode and a power down mode. A level shifter includes a level shifting unit(510) generating plural internal voltages, shifting voltage levels of plural input signals and outputting an output signal based on the internal voltages, and a mode control unit(520) controlling the voltage levels of the internal voltages in response to a mode selection signal. The input signals comprise a first signal with a first phase and a second signal with a second phase, the first and second phases not being the same. The mode selection signal indicates either of a normal mode and a power down mode.