| 摘要 |
PROBLEM TO BE SOLVED: To provide an amplifying circuit with an offset canceling function improved in sampling speed, and a high gain module using the same. SOLUTION: In the amplifying circuit provided with an amplifier 1 having two input and output terminals 2 to 5 whose polarities are different and a middle point potential input terminal 6, two external input and output terminals 8 to 11, two input capacitors 14, 15, two feedback capacitors 12, 13, first to sixth sampling switches 16 to 21, and first to third operational switches 22, 23 and 24, two input terminals of the amplifier is connected therebetween via a reset switch 26, then the reset switch is controlled so that the reset switch is turned on only when an initial predetermined period in a period in which each sampling switch is turned on. Deviation in the potential of input terminals and output terminals of the amplifier is reduced by reducing a current flowing through each sampling switch connected between the input and output terminals of the amplifier, and thereby the amplifier is configured so that a unity gain operation is quickly stabilized by forcibly pushing down a gap between the input terminals, and a sampling speed is raised. COPYRIGHT: (C)2007,JPO&INPIT
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