A low-power linear-logarithmic CMOS image sensor

In this paper, a new low-power complementary metal-oxide-semiconductor (CMOS) image sensor with adjustable light sensitivity is designed. The main pixel consists of five separate transistors and a comparator is used for the power consumption reduction with the pixel fill factor of 27%. Upon the pixel’s light-sensitive area receives light, the supply control applies 1.8 V, and in the input light absence, VDD is not applied to the circuit. This mechanism reduces the image sensor power consumption. A power consumption of 2.9 μW (at 2.5 nA photodiode current) is achieved. The proposed pixel is simulated using in 0.18 - μm standard CMOS technology.