Pulse Excitation Approach for Low Power Orthogonal Fluxgate Sensor

This paper investigates the working modes of orthogonal fluxgate sensor in pulse current excitation approach. A sensitivity of 6.7 mV/muT was obtained at a pulse frequency of 1 kHz with current amplitude of 20 mA and duty cycle of 0.04%. The power consumption of the sensor head could be as low as 6.4 muW, which shows great potential in application for sensors array and portable sensor devices. The orthogonal fluxgate sensor could work in pulse mode, second harmonic mode, or fundamental mode when it was driven by a pulse current with various duty cycles. The field behavior of the pulse excitation approach showed a large linear range. The pulse mode offered a compatible sensitivity to the other two modes and much lower power consumption due to a critical saturation energy.