Patent ID: 8203473

Claim:
A switched-capacitor input circuit which receives an analog input signal, and samples and holds the analog input signal, comprising: an amplifier; at least one capacitor, one terminal of the capacitor being connected to an input terminal of the amplifier; and a first switch configured to selectively connect the other terminal of the capacitor to one of a first reference voltage, a second reference voltage, and a third reference voltage; wherein the third reference voltage and the second reference voltage are higher than the first reference voltage, and the second reference voltage is an intermediate voltage between the first reference voltage and the third reference voltage, the first switch connects the other terminal of the capacitor to the first reference voltage so as to perform offset correction of ternary weight 0 , the first switch connects the other terminal of the capacitor to the second reference voltage so as to perform offset correction of ternary weight 1 , the first switch connects the other terminal of the capacitor to the third reference voltage so as to perform offset correction of ternary weight 2 , and the offset correction is done by ternary weighting.