| 摘要 |
An analogue switch formed on a semiconductor substrate comprises input and output ports (204, 205), and a first enhancement mode MOS transistor (201) formed in an isolated well in the substrate material and having its gate (G) connected to receive a control signal (207), and having one end (S) of its conducting channel and its well (W) connected to the input port (204). A second enhancement mode MOS transistor (202) is formed in an isolated well in the substrate, and has one end (S) of its conducting channel and its well (W) connected to the input port (204), and has its gate (G) connected to the other end (D) of the conducting channel of the first transistor (201). A third enhancement mode MOS transistor (203) is formed in an isolated well in the substrate, and has its gate (G) connected to receive the complement (208) of the said control signal, and has its conducting channel (D, S) connected between the output port (205) and the other end (D) of the conducting channel of the second transistor (202), and has its well (W) connected to one of the supply lines (OV) of the switch. Control means (210) are connected to the gate (G) of the second transistor (202) for maintaining the second transistor (202) in an opposite state to that of the first transistor (201).
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