Low-power global/rolling shutter image sensors in silicon on sapphire technology

A variety of low-power global shutter (snapshot) and rolling shutter active pixel sensors (APS) in silicon-on-sapphire (SOS) technology are presented. Utilizing the floating gate NMOS photodetector, operating in a lateral bipolar transistor (LBT) mode, the described imagers are expected to achieve high responsivity and are mostly suitable for low-power applications. The proposed global shutter sensors enable imaging of fast moving objects in the field of view. Power dissipation of the proposed imagers is reduced by employing an advanced gate-diffusion input (GDI) technique, used for the sensor digital periphery implementation. A test chip, consisting of four different 32×32 global shutter and rolling shutter image sensor arrays, operating at a power supply ranging from 1.2 V to 3 V, has been implemented in a Peregrine´s 0.5 μm SOS technology. System architectures and operation of the presented imagers are discussed, and a comparison with existing APS structures is presented as well.