US Patent 9948316 Analog-to-digital converter and CMOS image sensor including the same

An analog-to-digital converter includes a ramp signal generation unit suitable for decreasing a voltage range of a ramp signal in reverse proportion to a multiple of a gain and repeatedly generating the ramp signal by the multiple of the gain; a comparator suitable for repeatedly outputting a comparison signal by the multiple of the gain in response to the ramp signal; and a counter suitable for performing a counting operation in response to the comparison signal.