A low power linear output current-mediated CMOS imager

A novel CMOS current-mediated imager (CMI) is presented with high output linearity. In the proposed structure, the pixel operates in triode region, instead of operating in saturation region for conventional current-mediated imagers. As a consequence, the output current is a linear function of the photocurrent at the sensing node. Such a linear feature reduces the DC current consumption by more than a factor of 10 for high linearity applications. Additionally, the corresponding current source/mirror circuit is also presented, aiming to further minimize the linearity distortion caused by the Vds variation.