Low-power PCB fluxgate sensor

Abstract

New PCB (printed circuit board) technology flat fluxgate sensor with integrated coils and amorphous alloy core was developed and its excitation parameters were optimized for low-power consumption. The power consumption achieved with 10 kHz, 300 mA p-p pulse excitation with duty cycle 12.5% was only 3.9 mW, which is 3-times lower than that for sinewave flux density excitation. The sensor sensitivity reached 94 V/T. The required bridge supply voltage was only 0.47 V. The low-cost, low-power sensor has a temperature offset stability of 120 nT in the -20...+70 degC temperature range and 0.17%/degC open-loop sensitivity tempco due to the use of new core embedding technique. The perming error due to 10 mT field shock was suppressed below 1.2 muT