(C2) ;Hochspannungsschaltkreis

摘要

A high voltage switching circuit includes a buffer circuit 30 for buffering an input signal, a high voltage pumping circuit 40 for producing a desired voltage in response to an output signal of the buffer circuit 30, and a disconnecting circuit 50 for disconnecting the buffer circuit 30 and high voltage pumping circuit 40 when the output voltage of the buffer circuit 30 is a voltage Vcc and that of the high voltage pumping circuit 40 is a high voltage, wherein the disconnecting circuit 50 includes an enhancement transistor 34 and depletion transistor 36 connected in series, gates of the transistors being commonly connected to the voltage Vcc. In a second aspect the disconnecting circuit includes a transistor means having first and second channel regions of different conductivity type. <IMAGE>