Patent ID: 7928872

Claim:
An analog-to-digital converter comprising: a first preamplifier that receives a first reference voltage and an input signal; a second preamplifier that receives a second reference voltage and the input signal; a first preamplifier calibrator that is placed corresponding to the first preamplifier and adjusts an input offset of the first preamplifier; a second preamplifier calibrator that is placed corresponding to the second preamplifier and adjusts an input offset of the second preamplifier; an interpolator that is placed between an output terminal of the first preamplifier and an output terminal of the second preamplifier and generates an interpolation signal having a voltage value between a first output signal from the first preamplifier and a second output signal from the second preamplifier; a plurality of comparators that receive one of the first output signal, the second output signal and the interpolation signal and output a digital value based on the received signal; and a plurality of comparator calibrators that are placed respectively corresponding to at least comparators receiving the interpolation signal among the plurality of comparators and adjust input offsets of the corresponding comparators.