A monolithic positioning system

A monolithic positioning system operating with absolutely coded magnetic scales is presented. The system is intended for precise absolute positioning in industrial applications. Mounted to a tool the sensor-system moves along a stationary scale. 13 out of 52 sensors read out the magnetic coding allowing to calculate the absolute position. The main task has been cancelling the immense sensor offsets. Numerous structures have been measured in order to get statistically firmed data of sensitivity and offset variation. A sensor readout technique without large offset cancellation circuitry is discussed. Furthermore a novel linear operational transconductance amplifier (OTA) is shown. First measurements are presented.