Nonlinear effects in magnetic angular position sensor with integrated flux concentrator

Abstract

We studied nonlinear behaviour of the angular position magnetic field sensor that consists of CMOS integrated circuit chip and a thin ferromagnetic disk. Developed numerical 3D model was compared with experimental results with a good agreement. Obtained numerical results were used to determine the linear magnetic working range of the sensor. We also calculated the nonlinear error for the disk positioning relative to the Hall elements and found 3.3% of error for the 10 /spl mu/m displacement. We proposed a simple amplitude calibration to strongly reduce nonlinearity coming from misalignment to 0.3% of the full scale. Additional nonlinearity from Hall elements has been discussed. The offset and sensitivity mismatch, contribute to the nonlinearity of the sensor less than 1/spl deg/.