Patent ID: 7710304

Claim:
A differential input type A/D converter comprising an integration circuit or a sample hold circuit including first and second switched capacitor circuits to which first and second analog signals of opposite polarity are input, respectively, wherein said first switched capacitor circuit includes: a first sampling capacitor; a first switch connected between a first input terminal to which said first analog signal is input and one end of said first sampling capacitor and is turned on at a first timing; and a second switch connected between said one end of said first sampling capacitor and a reference supply and is turned on at a second timing, and wherein said second switched capacitor circuit includes: a second sampling capacitor; a third switch connected between a second input terminal to which said second analog signal is input and one end of said second sampling capacitor and is turned on at said first timing; and a fourth switch connected between said one end of said second sampling capacitor and a reference supply and is turned on at said second timing, and wherein said A/D converter further includes: a first noise cancel circuit for supplying a signal to cancel a kickback noise generated in said first input terminal when said first switch is turned on to said first input terminal at said first timing; and a second noise cancel circuit for supplying the signal to cancel the kickback noise generated in said second input terminal when said third switch is turned on to said second input terminal at said first timing.