An analog integrated circuit for continuous-time gain and offset calibration of sensor arrays

Parameter variations cause unavoidable nonuniformities in Infra-Red Focal Plane Arrays and other integrated sensors. Since these nonuniformities change slowly with time, calibrating sensors onetime only is not suitable-much more frequent calibration is required. We have developed an algorithm that continually calibrates an array of sensors that contain gain and offset variations. This algorithm has been mapped to analog hardware and designed and fabricated with a 2um CMOS technology, Measured results from the chip show that the system achieves invariance to gain and offset variations of the input signal.