| 摘要 |
PROBLEM TO BE SOLVED: To improve the performance of a circuit device which converts a minute-amplitude alternating current signal to a large-amplitude voltage signal using an integration circuit. SOLUTION: An output voltage from an integration circuit operational amplifier is stored in a first capacitor 6 at a first phase in a period of an input alternating current signal, and the output voltage from the integration circuit operational amplifier is stored in a second capacitor 8 at a second phase with a shift of 180 degrees from the first phase. Then, the stored voltages of the first capacitor 6 and the second capacitor 8 are read to be added at a third phase, and a stored voltage of a third capacitor 10 is subtracted from the added voltage. The voltage that is the subtraction result is stored in the third capacitor 10, and a correction current is inputted as an inverting input of the integration circuit operational amplifier based on the stored voltage of the third capacitor 10. COPYRIGHT: (C)2009,JPO&INPIT
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