A 0.5V 4.95μW 11.8fps PWM CMOS imager with 82dB dynamic range and 0.055% fixed-pattern noise

Abstract

In this paper, a 0.5V 64×40-pixel PWM imager is prototyped in standard 0.18μm CMOS. A threshold-variation-cancelling (TVC) scheme is developed to solve the non-uniformity issue of in-pixel comparators, which results in 0.055% fixed-pattern noise (FPN). To deal with the limited signal swing at 0.5V operation, a programmable current-controlled threshold (PCCT) scheme is implemented to achieve a 56.5dB boost in dynamic range.