23, 000-Exposures/s 360fps-Readout Software-Defined Image Sensor with Motion-Adaptive Spatially Varying Imaging Speed

Roberto Rangel, Xiaonong Sun, Ayandev Barman, Rahul Gulve, Savo Bajic, Jingmin Wang, Harry Wang, David B. Lindell, Kiriakos N. Kutulakos, Roman Genov

Abstract: The software-defined VGA image sensor adapts to fast changes in the scene, both locally and globally, by taking advantage of programmable-size/speed super-pixels and scalable-rate SAR ADCs, respectively. Each super-pixel includes up to 8×8 pixels exposed in a rapid sequence within one frame period, yielding a 64x maximum boost of the exposure rate over the output rate, without the corresponding increase in the ADC power. At 360fps readout, this corresponds to over 23,000 exposures/s while using only 24.5mW, and comes at the cost of moderately lower local resolution, only in the regions with the fast changes in the scene. The 54fJ-FoM SAR ADC allows for scaling down to the 30fps ‘slow’ mode, yielding an additional factor of 12x savings in the output data and camera digital power, and 30% savings in the ADC power.