| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable gain circuit capable of varying its gain in response to a voltage and the adjustment of the gain of which can easily be performed. SOLUTION: The variable gain circuit the gain of which is controlled in response to the voltage is characterized by including: a plurality of gain control circuits (M11, M21, M31; R21 to R23, R31 to R33, R41 to R43); and a control circuit (M12, M22, M32, IF circuits 131, 132, 133) for controlling the gain by switching connections of the gain control circuits (M11, M21, M31; R21 to R23, R31 to R33, R41 to R43) in response to the voltage. COPYRIGHT: (C)2007,JPO&INPIT
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