Patent ID: 7403151

Claim:
A switch control circuit of an integrator, the integrator including: an operational amplifier that has an input terminal and an output terminal; a first capacitor that has first and second electrodes, the first electrode being electrically connected to the output terminal of the operational amplifier, the second electrode being electrically connected to the input terminal of the operational amplifier; a second capacitor that has third and fourth electrodes; a first switch that intervenes between the third electrode of the second capacitor and the input terminal of the operational amplifier; a second switch that causes a reference voltage to be applied to the third electrode of the second capacitor; a third switch that causes an input voltage to be applied to the fourth electrode of the second capacitor; and a fourth switch that causes the reference voltage to be applied to the fourth electrode of the second capacitor, the switch control circuit turning on/off the second and third switches of the integrator, while turning off/on the first and fourth switches of the integrator, in a complementary manner, wherein the switch control circuit turns off the first switch after turning on the first and fourth switches, turns on the second switch after turning off the first switch, and turns the fourth and third switches off and on, respectively, after turning on the second switch.