Power Reduction and Fill Factor Improvement on Designing Smart Image Sensor with Motion Detection Capability

Power consumption and fill factor improvement are known as the vitally important parameters in evaluating smart image sensors. In this paper, due to considering two different operation modes in processing different frames, and also designing power management unit, the amount of redundant data processed in unimportant frames has been reduced significantly, and therefore the proposed imaging system consumes less power compared with counterpart imagers. Furthermore, a novel pixel structure is introduced that outputs two consecutive frame voltages in series, with the result that the pixel size is minimized and a higher fill factor is achieved. The performance of this technique is demonstrated using a 64×64 pixel sensor designed in a 0.18µm standard CMOS technology. The sensor chip consumes 0.2mW of power while operating at 100fps with a fill factor of 45%.