A Fluxgate Magnetic Sensor: From PCB to Micro-Integrated Technology

In this paper, a double-axis micro Fluxgate magnetic sensor is presented. The device represents an evolution of a PCB dual axis sensor previously realized. In the PCB version the experimental results exhibit excellent agreement with the simulations performed using a tool based on the finite element method. Using the same design approach a version of double-axis Fluxgate structure is here proposed to be realized in IC technology. The accurate study of the magnetic field distribution allows a 75% area saving for the IC version with respect to a direct scaling of the PCB version. Imposing an external magnetic field of about 60 muT, the simulated differential output voltage of the micro-integrated Fluxgate sensor achieves a peak value of 1 mV with 5 mA sinusoidal excitation current peak at 100 kHz. The integrated microstructure shows a linearity error of about 1.15% of the full scale, in the range of plusmn50 muT, with a sensitivity of about 0.45 mV/muT