Patent ID: 8462246

Claim:
A method for CDS (correlated double sampling) and ADC (analog to digital conversion) in an image sensor, comprising: sampling a pixel signal from a given pixel to generate a respective sampled signal N-times to perform N reset signal samplings and sampling another pixel signal from the given pixel to generate another respective sampled signal N-times to perform N image signal samplings, with N>1 within a horizontal scan time period of the image sensor; generating a ramp signal with a respective ramping portion for each respective sampled signal; comparing each respective sampled signal with a respective ramping portion to generate a respective comparison signal; generating a respective digital code from each respective comparison signal; counting a respective clock signal from the respective ramping portion beginning to ramp until a logical transition of the respective comparison signal to generate the respective digital code for each respective sampled signal, wherein the respective clock signal for each respective sampled signal generated N times forms N respective clock signals, and wherein each respective sampled signal generated N times forms N respective sampled signals; and generating the respective clock signals to be successively phase-shifted by 360°/N for the N respective sampled signals.