Analog-digital converter and image sensor including the same

Abstract

An image sensor according to some example embodiments includes a pixel array outputting a pixel signal, a detection circuit determining a comparison result signal based on a reference signal and the pixel signal and outputting the comparison result signal, an analog-to-digital converter outputting a count result signal based on the comparison result signal, and a sense amplifier outputting an image signal based on the count result signal, the analog-digital converter including a divider generating a divided reference clock signal by dividing a reference clock signal, a delay circuit generating a first gray code signal by delaying the divided reference clock signal, a code generator generating second gray code signals having different periods from the first gray code signal based on the divided reference clock signal, and a delay control circuit providing a delay control signal that controls a delay time of the divided reference clock signal to the delay circuit.