A High Fill Factor, Power-Gated Smart Image Sensor with a Novel Simulation Methodology

This paper presents an ultra-low power, high fill factor smart vision system for real-time motion detection. In case of power consumption, our main focus is to curb the amount of redundant data generated in unimportant frames. Considering non-operating pixels, the proposed image sensor has two different operation modes so that important frames, in which a motion has been detected, are processed in full resolution, while the normal ones are reported by only a portion pixels of the array. Fill factor improvement is another significant achievement of the proposed methodology which is achieved by developing an in-pixel event generator in column-level and also designing a novel pixel structure which outputs two consecutive frame voltages using only one readout path in series. Furthermore, in order to simulate the image capturing procedure, a state-of-the-art approach based on MATLAB and HSPICE software interaction is introduced which is efficient in cost, time, and power. 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 49%.

Keywords:

CMOS image sensor , motion detection , low power consumption , fill factor , simulation method