| 摘要 |
PROBLEM TO BE SOLVED: To be able to remain electric potential of an I/O terminal unchanged, regardless of ON/OFF states of an analog switch. SOLUTION: The analog switch circuit is equipped with an analog switch 10 composed of a first P channel MOS transistor P1 and a first N channel transistor N1 for receiving a control signal at its gate, a comparison circuit 20 for comparing electric potential of a first input/output terminal with the one of a second input/output terminal to deliver the higher electric potential to a well where the first P channel MOS transistor P1 is formed at, a first electric potential delivery unit 30 for delivering electric potential of the well, where the first P channel MOS transistor P1 is formed, to the gate of the first P channel MOS transistor P1 during analog switch turn-off, a second electric potential delivery unit 40 for operating based on the control signal to deliver electric potential of the well, where the first P channel MOS transistor P1 is formed, to the gate of the first P channel MOS transistor P1 and to turn off the first P channel MOS transistor P1, and a third electric potential delivery unit 50 for operating based on the control signal to turn on the first P channel MOS transistor P1. COPYRIGHT: (C)2003,JPO
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