Improving the dynamic range of CMOS image sensor using feedback reset mechanism(Poster session,2nd Asian Image Sensors and Imaging Systems Symposium)

Abstract

In this paper, we proposed a novel image sensor using a feedback reset mechanism. To extend the dynamic range, an additional feedback circuit which is composed of a comparator and a voltage converter is needed. The floating diffusion node in the APS is reset to the medium voltage at high illumination. The proposed image sensor is based on the 3-transistor active pixel sensor (APS). It is possible to switch back and forth between normal mode and feedback reset mode, and to control both feedback reset time and voltage values. The proposed image sensor was designed and fabricated with a 0.35 μm 2-poly 4-metal CMOS process.