JP2934488B

A voltage comparator is provided including a differential amplifier, first, second and third switches, and first and second capacitors. A fourth switch is connected in series between the second and third switches and an input terminal of the differential amplifier. A first input voltage is sampled and held at the first capacitor through the first switch and at the second capacitor through the second and fourth switches, respectively. Thereafter, since the third switch is turned on and the fourth switch is turned off, the first input voltage is sampled and held at the input capacitor of the differential amplifier. Thereafter, the third switch is turned off and the fourth switch turned on. As a result, an on and off operation of the fourth switch is controlled so that a second input voltage which has been sampled at the second capacitor immediately before the switch is turned off is applied to the input capacitor of the differential amplifier.