High Speed Digital CMOS 2D Optical Position Sensitive Detector

In this paper we present a 2-D optical sensor array for position sensing applications. The 20 by 20 pixels sensor implements an analog insensive parallel computation for the estimation of the centroid of a light distribution impinging on the photosensitive area. The photogenerated signal is first analog preprocessed by means of a distributed image peak detector; contour digitization follows extracting the image centroid position. The sensor, fabricated in standard 0.8um CMOS technology performs up to 250k frames/s and exhibits a power consumption which is proportional to the square root of the number of pixels