An angle measurement solution from Analog Devices app note (PDF!).
An AMR (anisotropicmagneto resistive) angle measurement solution with 1°angular accuracy over a 180° range. The circuit is ideal for applications where high speed, accurate, non-contact angle measurements are critical.
The circuit provides all necessary signal conditioning including instrumentation amplifiers, buffers, and a dual channel ADC that efficiently process the AMR sensor low level bridge outputs. The result is an industry leading angle measurement solution suitable for machine tool speed control, crane angle control, motor speed measurement, and other industrial or automotive applications.