Patent ID: 8681033

Claim:
An analog-to-digital converter, comprising: a voltage generating unit configured to divide an externally applied reference voltage by a plurality of resistors to generate a plurality of comparative voltages; and a plurality of comparators each configured to compare any one of the plurality of comparative voltages with an analog input voltage and output a digital signal based on a result of a comparison between the comparative voltage and the analog input voltage, wherein each of the plurality of comparators includes a differential pair circuit configured to detect a potential difference between two inputs of the comparative voltage and the analog input voltage, the differential pair circuit includes a first circuit portion and a second circuit portion, the first circuit portion includes: a first input transistor having a gate to which one input is supplied; and a resistor which is connected in series with the first input transistor, the second circuit portion includes: a second input transistor that has a gate to which the other input is supplied and forms a differential pair with the first input transistor; and a variable resistor which is connected in series with the second input transistor, and the variable resistor includes a plurality of variable resistive elements which are connected in series, and each of the variable resistive elements has a resistance value variably set according to a control signal.