A low power micro fluxgate sensor with improved magnetic core

The influence of an improved magnetic core on the micro fluxgate sensor about sensitivity and power consumption is investigated and discussed in this paper. We have fabricated the micro solenoid fluxgate sensors based on the MEMS technologies, with the electroplating permalloy cores, which are easy to process and used in common; and the amorphous soft magnetic ribbon cores, which have better soft magnetic performances but be hard to be integrated, respectively. Four magnetic core structures are designed, including rectangular structure, unequal width rectangular structure, multi rectangular ring structure and spiral structure. Spiral structure can improve the performances of the fluxgate sensor significantly, both sensitivity and power consumption. The micro fluxgate sensors with the amorphous soft magnetic ribbon cores are promoted in all aspects than those with the electroplating permalloy cores, including ultra low power consumption of 2.4 mW with unequal width rectangular structure, and high sensitivity of 118 V/T with rectangular structure in wide linear range of 0–800 μT.