A 240x180 120dB 10mW 12us‐latency sparse output vision sensor for mobile applications

Abstract

This paper proposes a CMOS vision sensor that combines event-driven asynchronous readout of temporal contrast with synchronous frame-based active pixel sensor (APS) readout of intensity. The image frames can be used for scene content analysis and the temporal contrast events can be used to track fast moving objects, to adjust the frame rate, or to guide a region of interest readout. Therefore the sensor is suitable for mobile applications because it allows low latency at low data rate and low system-level power consumption. Sharing the photodiode for both readout types allows a compact pixel design that is 60% smaller than a comparable design. The 240x180 sensor has a power consumption of 10mW. It is built in 0.18um technology with 18.5um pixels. The temporal contrast pathway has a minimum latency of 12us, a dynamic range of 120dB, 12% contrast detection threshold and 3.5% contrast matching. The APS readout has 55dB dynamic range with 1% FPN.