A 121.8dB Dynamic Range CMOS Image Sensor using Pixel-Variation-Free Midpoint Potential Drive and Overlapping Multiple Exposures

This paper presents a wide dynamic range CMOS image sen-sor using a pixel-variation-free midpoint potential drive with a double midpoint shutter. No degradation of the sensitivity is seen due to continuing charge integration. The double midpoint shutter suppresses the fixed pattern noise of short-exposure im-ages and realizes high linearity throughout the full scale. We have developed a 2M pixel prototype using a 0.18 µm CMOS process with three 90 nm Cu layers. Wide dynamic range op-eration up to 121.8 dB has been successfully demonstrated