A 64 64 Pixels UWBWireless Temporal-Difference Digital Image Sensor

In this paper we present a low power temporal-difference image sensor with wireless communication capability designed specifically for imaging sensor networks. The event-based image sensor features a 64 64 pixel array and can also report standard analog intensity images. An ultra-wide-band radio channel allows to transmit digital temporal difference images wirelessly to a receiver with high rates and reduced power consumption. The sensor can wake up the radio when it detects a specific number of pixels intensity modulation, so that only significant frames are communicated. The prototype chip was implemented using a 2-poly 3-metal AMIS 0.5 m CMOS process. Power consumption is 0.9 mW for the sensor and 15 mW for radio transmission to distance of 4 m with rates of 1.3 Mbps and 160 fps.