The AD2S90 is a complete 12-bit resolution tracking resolver-to-digital converter. No external components are required to operate the device. The converter accepts 2 V rms ± 10% input signals in the range 3 kHz–20 kHz on the SIN, COS and REF inputs. A Type II servo loop is employed to track the inputs and convert the input SIN and COS information into a digital representation of the input angle. This document describes the features and characteristics of the AD2S90, as well as its applications in industrial motor control, servo motor control, industrial gauging, encoder emulation, automotive motion sensing and control, factory automation, and limit switching.