A focal plane processor for continuous-time 1-D optical correlation applications

This paper describes a 1-D Focal Plane Processor incorporating 200 pixels for Continuous-Time Optical Correlation Applications. Each pixel incorporates a 2 mm times 10.9 mum photodiode whose current is scaled, at the pixel level, by 5 independent 3-bit programmable-gain current amplifiers. Correlation patterns, defined as 5 sets of 200 3-bits numbers, are communicated to the chip via a standard I²C interface. Correlation outputs are provided in current form through independent 8-bit-programmable amplifiers whose gains are also defined via I²C. The chip contains an alignment help by incorporating 3 rows of 100 conventional Active Pixel Sensors (APS) inserted at the top, middle, and lower part of the main photodiode array. The chip has been fabricated in a standard 0.35 mum CMOS technology and maximum power consumption is below 30 mW.