A fluxgate sensor interface,Application Specific Intergrate Circuits(ASIC) based on the Complementary Metal Oxide Semiconductor(CMOS),is designed and manufactured by a 0.6 μm DPDM P-sub brief process and the second-harmonic detection of output voltage.This kind of integrated interface circuit of the fluxgate can decrease the dimension of traditional discrete components,and can reduce the power consumption to meet the requirements for miniaturization and low-power consumption in aviation and military domains.In consideration of the structure and specification of the fluxgate sensor,the excitation and pick-up circuits with the size of 2 mm×2 mm for the sensor are proposed,and the functions and parameters of all parts of the circuits are verified by a HSPICE.The experiment results of the circuit system with the fluxgate sensor show that the circuit can offer a sensitivity of 16.5 μV/nT and the linear ranges of ±90 μT.With a voltage supply of 5 V,the total power consumption of the circuit is as low as 35 mW.