SWITCHED CAPACITOR CIRCUIT AND CORRECTION METHOD FOR ERROR COMPONENT DUE TO FINITE GAIN OF OPERATIONAL AMPLIFIER CONSTITUTING THE CIRCUIT

摘要

PROBLEM TO BE SOLVED: To correct an error difference which occurs since the DC gain of an operational amplifier is finite in a switched capacitor circuit constituted by using an operational amplifier. ;SOLUTION: An operational amplifier 1 where a noninverting input terminal is grounded, capacitors C1 and C2 connected to the inverting input terminal of the operational amplifier 1 in parallel, switches SW1 and SW2 which are connected to each end of the capacitors C1 and C2 and can be open/close- controlled by control signals (not illustrated), switches SW3 and SW4 which are connected between the ends of the capacitors C2 and ground points and can be open/close-controlled by control signals (not illustrated) and a switch SW5 which is connected to the output terminal of the operational amplifier 1 and one end of the capacitor C1 and can be open/close-controlled by the control signal which is not illustrated are provided. Fine capacitor C3 is installed in parallel to the capacitor C2.;COPYRIGHT: (C)2000,JPO