CMOS Neuromorphic Optical Sensor Chip With Color Change-Intensity Change Disambiguation (CCICD)

In this paper, we propose a novel terrestrial retina-like neuromorphic sensor chip which can (1) perform irradiance and color detection via two pathways simultaneously and (2) can perform color change-intensity change disambiguation (CCICD). The irradiance detection pathway has a wide-dynamic detection range, spanning 3 orders of magnitude, and is robust to background light variations. The color detection pathway has a buried double junction photodiode as the photoreceptor followed by two parallel logarithmic I-V convertors whose outputs go to a differential amplifier. The output from this pathway is a color response which has roughly 50 nm resolution for wavelengths from 400 to 700 nm, and 22 nm resolution between 700–900 nm. With these two pathways, we can perform CCICD to determine if a change in the output of the irradiance pathway is because of irradiance change, color change, or both. This terrestrial retina-like neuromorphic sensor chip is implemented in AMI 1.5 µm technology, a standard CMOS fabrication process available at MOSIS.