| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable resistance circuit whose parasitic capacity is small and which uses a MOS transistor with a small fluctuation in production and controls a resistance value continuously. SOLUTION: A constant-current source 5 to be controlled by voltages, voltage generation portions 7, 8, 9 and 10 to generate the voltages proportional to currents of the constant-current source at a first and a second terminals of three terminal elements, and a variable resistance portion consisting of a MOS transistor 6 are provided. The voltages generated in a voltage generation circuit are supplied to both ends of the MOS transistor and impedances of both the ends of the MOS transistor are varied according to the voltages generated in the voltage generation circuit. COPYRIGHT: (C)2004,JPO
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