| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a capacitance detection circuit with improved detection accuracy and without offsets. Ž<P>SOLUTION: In the capacitance detection circuit, when two feedback capacitors C30 and C40 connected to a fully-differential amplifier 131 to perform charge detection are differed in capacitance, resulting offset is eliminated by switching of a switching circuit 140 provided between two capacitance elements C10 and C20 and two input terminals T11 and T12 of the total differential amplifier 131, and a switching circuit 150, provided between two output terminals T13 and T14 of the fully-differential amplifier 131 and output terminals T20 and T30 of the capacitance detection circuit. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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