Wide dynamic range CMOS image sensor based on dual exposure technique using averaging circuits

Abstract

In this paper, an averaging circuits using dual exposure technique for extending dynamic range of CMOS image sensor is proposed. The proposed CMOS image sensor has been implemented by a chip which is consisted of a pixel array, scanners, and proposed averaging circuits. Despite the equal number of transistors in pixels, it is possible to extend dynamic range of CMOS image sensor by using averaging circuit. In addition, comparing with conventional 3-transistor CMOS image sensor, it was demonstrated that dynamic range is improved from 70dB to 90dB after using average circuit by experimentally. The designed circuit has been fabricated by using 0.18μm 1-poly 6-metal standard CMOS process, and its characteristics are simulated and measured.