A 12.6 mW 8.3 Mevents/s contrast detection 128×128 imager with 75 dB intra-scene DR asynchronous random-access digital readout

Abstract

We present a temporal contrast detection event-driven asynchronous 128×128 pixel image sensor with integrated 10-bit ADC intensity readout in 0.18 μm 6M 1P CMOS. Current-mode log-compressed readout with correlated double sampling (CDS) offset compensation provides random access to instantaneous pixel intensity over 75 dB intra-scene dynamic range. Temporal correlated double sampling in 'on' and 'off' transient event detection reduces capacitor sizing requirements within the pixel. Global threshold adaptation using common-mode capacitive coupling across the pixel array compensates for global scene lighting variations. Power consumption at 8.3 Mevents/s is 12.6 mW from a 1.8 V supply, or 1.52 nJ per pixel event detection and readout. Die size is 5mm×5mm and pixel size is 33μm×33μm with 22.8% fill factor.