An integrated GMR (Giant Magneto Resistance) angle sensor will be presented which is designed to fulfill requirements for electrical commutated motor-drives. These motors use sine-commutation for the coils and need the angle of the motor-shaft in accuracy ranges below 1° with update-rates of 50-100μs. This integrated GMR Angle sensor solves this problem using integrated GMR Angle-Sensors on top of the silicon signal processing chip. The differential GMR-bridge signals are converted to the digital domain by sigma-delta ADCs and these raw-signals are error-compensated. An additional autocalibration feature is implemented to improve the accuracy during operation. The very fast angle-measurement is performed using parallel analog signal processing, 24MHz finite state machine with dedicated peripherals and an 8Mbit/s SPI interface. An additional feature to reduce the time delay is the implemented angle-value prediction. Built-in selftests, switchable voltages for signal-path tests and multiple safety voltage comparators are implemented for safety-critical applications.
Granig, W., Weinberger, M., Reidl, C., Bresch, M., Strasser, M., & Pircher, G. (2010). Integrated GMR angle sensor for electrical commutated motors including features for safety critical applications. In Procedia Engineering (Vol. 5, pp. 1384–1387). Elsevier Ltd. https://doi.org/10.1016/j.proeng.2010.09.373