High resolution Hall magnetic sensors

Abstract

The resolution of a magnetic sensor depends on its intrinsic noise, offset instability and the magnetic sensitivity. Both noise and offset can be substantially reduced by the spinning current technique. The effective magnetic sensitivity can be increased by the application of a magnetic flux concentrator. The physical limit of magnetic sensitivity is estimated. Values of sensitivity, noise and offset of various discrete and integrated horizontal and vertical Hall devices, and of sensor systems are given. High resolution integrated Hall sensors are currently mostly used as compass in mobile phones.