A Quadratic Analog-to-Digital Converter

In background noise limited instrumentation systems, an analog-to-digital converter with a square root transfer function will allow a maximum dynamic range with a fixed number of data bits. The converter described herein was developed to digitize the output from a CCD in a space environment where telemetry is limited. The goals of low power dissipation, moderately fast conversion time, and reliability have been achieved using standard components and avoiding non-linear elements.