An analog-to-digital converter (ADC) is provided. The ADC may include an input terminal configured to receive input signals, a digital-to-analog converter (DAC), a first switch configured to control a connection between the DAC and the input terminal, a comparator, a second switch configured to control a connection between the DAC and the comparator, and a controller configured to control the first switch, the second switch, the DAC and the comparator.