Patent ID: 7420499
Filing Date: 2008-09-02
Classification: H03M

Abstract:
1. An analog-to-digital (A-D) converter, which converts an analog signal to a digital signal, the A-D converter comprising: a plurality of comparator circuits which compare an input analog voltage with a plurality of different threshold values; a threshold voltage selection circuit which selects voltages inputted to said plurality of comparator circuits, as the plurality of different threshold values; a reference voltage output circuit which outputs a correction reference analog voltage which is to be inputted to said plurality of comparator circuits when the selection of voltage by said threshold voltage circuit is to be corrected; and a track-and-hold circuit which holds temporarily the input analog voltage and inputs it to said plurality of comparator circuits, wherein the track-and-hold circuit includes: a first switch which switches between the input and shutoff of the input analog voltage; a second switch which switches between the input and shutoff of the correction reference analog voltage; a capacitor connected between a path connecting the first switch and the second switch to the plurality of comparator circuits, and a predetermined fixed potential.