An integrated linear position sensitive detector with digital output

An integrated linear position sensitive detector (PSD) with digital output is presented. A novel interpolating analog-to-digital converter based on a sigma-delta converter is applied to perform three operations simultaneously. These are calculations of the relative position, cancellation of errors of both an optical and an electrical nature, and generation of a digital output. The digital output format allows serial bus communication. The realized 6.5*2.5 mm/sup 2/ smart sensor is integrated in a standard bipolar IC process.<<ETX>>