Research on AMR Sensors' Anti-interference Circuit

Aiming at the problems of the decline of both accuracy and sensitivity of the anisotropic magneto resistive (AMR) sensors caused by outside interference, this paper puts forward the applied set or reset pulse to generate strong magnetic field to restore and solve the problem, and takes 3-axis AMR sensor HMC2003 as an example, introducing its basic parameters, analyzing the working principle of Set/Reset (SR) pulse and simulating the SR circuit composed of filed effect transistors. Finally, relevant experiments are done with this circuit. The experimental results show that the sensor with SR circuit has a stronger anti-interference capability and a higher detection accuracy than the one without SR circuit in the geomagnetic field.