Contactless angle measurement using four Hall devices on single chip

A novel method for contactless angle detection is presented. It is based on four Hall devices on a single industrial CMOS chip in combination with a permanent magnet. The system setup and the Hall devices implemented are described. Measurements show an angular accuracy of ±0.3° over the range of 360°. We also measured the magnetic field distribution in the chip plane. Based on this, the robustness of the angular accuracy against mechanical tolerances is investigated. Lateral misalignment below 100 μm of the chip or the magnet to the axis of rotation causes an angle error below ±1°. A tilt of 1.5° between magnet and chip results in ±0.5°. A worst case combination of the three effects still results in an accuracy better than ±3.6