Circular Hall Transducer for Angular Position Sensing

We developed a new integrated magnetic sensor based on the Hall effect, suitable for contactless 360deg absolute angle encoding. The sensing device consists of a narrow n-well ring with a chain of 64 contacts equally distributed along the ring. It is connected to on-chip biasing and signal conditioning circuits that provides the magnitude and the phase of the in-plane component of the magnetic field. In a homogenous magnetic field, the transducer angular resolution is 0.01deg in the 1 kHz frequency bandwidth and the absolute accuracy is about 1deg and 0.1deg without and with output offset calibration, respectively.