FD-SOI-Based Pixel With Real-Time Frame Difference for Motion Extraction and Image Preprocessing

A frame differencing pixel (FDP) design based on fully depleted silicon-on-insulator (FD-SOI) technology is presented, demonstrating the capability of the FDP to perform pixel-level real-time frame difference (FD) for motion extraction and image preprocessing. The photo charges are collected by the diode under the buried oxide (BOX) and sensed by the MOSFET above. The capacitance of the BOX is used to generate the FD signal without incurring more area costs. TCAD simulations of the FD-SOI FDP were performed to help the analysis. An optimal pixel design model was developed to describe the relationship between noise performance and area allocation. According to the simulation results, the FDP could achieve light sensitivity of $25.6 ~\mu \text{A}$ /( $\mu \text{J}$ /cm2) and a differential signal-to-noise ratio of 35 dB with a $4 ~\mu \text{m}$ pixel pitch and 76% fill factor.