A 128 128 1.5% Contrast Sensitivity 0.9% FPN 3 µs Latency 4 mW Asynchronous Frame-Free Dynamic Vision Sensor Using Transimpedance Preampli fiers

Abstract

Dynamic Vision Sensors (DVS) have recently ap- peared as a new paradigm for vision sensing and processing. They feature unique characteristics such as contrast coding under wide illumination variation, micro -second latency response to fast stimuli, and low output data rates (which greatly improves the efficiency of post-processing stage s). They can track extremely fast objects (e.g., time resolution is b etter than 100 kFrames/s video) without special lighting conditions. Their availability has triggered a new range of vision applications in the fields of surveillance, motion analyses, robotics, and mic roscopic dynamic observations. One key DVS feature is contrast sensitivity, which has so far been reported to be in the 10–15% range. In this paper, a novel pixel photo sensing and transimpedance pre-ampli fication stage makes it possible to improve by one order of magnitud e contrast sensitivity (down to 1.5%) and power (down to 4 mW), reduce the best reported FPN (Fixed Pattern Noise) by a factor of 2 (down to 0.9%), while maintaining the shortest repor ted latency (3 s) and good Dynamic Range (120 dB), and further reducing overall area (down to 30 31 m per pixel). The only penalty is the limitation of intrascene Dynamic Range to 3 decades. A 128 128 DVS test prototype has been fabricated in standard 0.35 mC M O Sa n d extensive experimental characterization results are provided.