A CMOS 2D Micro-Fluxgate Earth Magnetic Field Detecting System with RS232 Digital Output

In this paper we present an acquisition system to measure the Earth magnetic field whose full-scale value is of the order of 60μT), consisting of a microcontrolled management subsystem, a CMOS integrated interface circuit and a 2D integrated micro-fluxgate magnetic sensor. The couple of orthogonal axis of the sensor makes the system suitable for realizing an electronic compass device. The complete acquisition system achieves an accuracy resulting in a maximum error of 1.5° in the measurement of the Earth's magnetic field direction, providing a digital output through an RS232 serial interface. Furthermore a measurement setup was developed to evaluate the acquisition system performances. It consist of a precision mechanical structure, in tower form, of a PC software properly developed to post process the data from the acquisition system and of a Helmholtz Coils device to estimate the linearity of the system. This setup allows to perform a completely automated and numerically controlled characterization of the acquisition system. © 2007 IEEE.