fig2 the level converters lvcn 1 and lvcn 2 may be substantially the same circuits the level converter lvcn 1 converts a high level of the oscillation signal u03c6 03 from the power supply voltage vcc into a high voltage vhigh the level converter lvcn 2 converts a high level of the oscillation signal u03c6 04 from the power supply voltage vcc into a high voltage vhigh the buffer buf 1 operates by receiving the power supply voltage vcc and a grounding voltage vss the buffer buf 1 includes an even number of serially coupled inverters for each of the oscillation signals u03c6 01 and u03c6 02 the buffer buf 1 outputs the oscillation signal u03c6 1 substantially in synchronization with the oscillation signal u03c6 01 and outputs the oscillation signal u03c6 2 substantially in synchronization with the oscillation signal u03c6 02 the amplitude of the oscillation signals u03c6 1 and u03c6 2 is about 5 v that is substantially equal to the power supply voltage vcc the buffer buf 2 operates by receiving the high voltage vhigh and the grounding voltage vss the buffer buf 2 includes an even number of serially coupled inverters for each of the oscillation signals u03c6 03 and u03c6 04 the buffer buf 2 outputs the oscillation signal u03c6 3 substantially in synchronization with the oscillation signal u03c6 03.