A Microbolometer Asynchronous Dynamic Vision Sensor for LWIR

In this paper, a novel event-based dynamic IR vision sensor is presented. The device combines an uncooled microbolometer array with biology-inspired ("neuromorphic") readout circuitry to implement an asynchronous, "spiking" vision sensor for the 8-15 mu m thermal infrared spectral range. The sensor's autonomous pixels independently respond to changes in thermal IR radiation and communicate detected variations in the form of asynchronous "address-events." The 64 x 64 pixel ROIC chip has been fabricated in a 0.35 mu m 2P4M standard CMOS process, covers about 4 x 4 mm(2) of silicon area and consumes 8 mW of power. An amorphous silicon (a-Si) microbolometer array has been processed on top of the ROIC and contacted to the pixel circuits. We discuss the bolometer detector properties, describe the pixel circuits and the implemented sensor architecture, and show measurement results of the readout circuits. Subsequently, a DFT-based approach to the characterization of asynchronous, spiking sensor arrays is discussed and applied. Test results and analysis of sensitivity, bandwidth, and noise of the fabricated IR sensor prototype are presented.