HIGH-SPEED AND LOW-POWER ANALOG-TO-DIGITAL CONVERTER AND CMOS IMAGE SENSOR USING THE SAME

摘要

An ADC includes: a ramp signal selector suitable for selecting a ramp signal selector suitable for selecting a rising half ramp signal or falling half ramp signal according to a ramping direction detection result from a ramping direction detector; a comparator suitable for outputting an initial comparison result signal by initially comparing a half ramp signal and a pixel signal, and outputting a comparison result signal by comparing the rising or falling half ramp signal selected through the ramp signal selector to the pixel signal; the ramping direction detector suitable for detecting a ramping direction according to the initial comparison result signal from the comparator; and a data converter suitable for deciding an initial bit according to the initial comparison result signal from the comparator, and performing data conversion according to the comparison result signal from the comparator.