ABSTRACT The design and performances of a high dynamic range DC-AC current sensor utilizing Giant Magneto-Impedance (GMI) are presented. The sensor is based on a GMI element with negative feedback. The sensing element is a 30 μm diameter GMI Co-based amorphous wire. It is curled to a toroidal core of 2 cm diameter. A bias magnetic field of about 650 A/m is applied to the GMI element to obtain an asymmetric GMI effect. A strong negative feedback is introduced to ensure linearity in a wide dynamic range. Analog conditioning electronics was fully developed. This includes a square wave oscillator based on an inverter trigger; a peak detector and a high gain amplifier with zero adjust. The GMI element is driven at a 3 MHz frequency and 5 mA peak-to-peak current. The closed-loop operations are investigated and the performances of the sensor are presented. DC current measurements are performed. The sensor exhibits good sensitivity and very good linearity, free from hysteresis, in a wide dynamic range of ±40 A. The sensitivity is about 0.24 V/A and the linearity error is about 0.02% of the full scale (FS). The hysteresis error is smaller than the measurement accuracy. AC current measurements using the developed sensor have also been successfully achieved. The sensor bandwidth in closed-loop was about 1.7 kHz.
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A. Asfour, J. Yonnet and M. Zidi, "A High Dynamic Range GMI Current Sensor," Journal of Sensor Technology, Vol. 2 No. 4, 2012, pp. 165-171. doi: 10.4236/jst.2012.24023.
 H. Hauser, L. Kraus and P. Ripka,“Giant Magnetoimpedance Sensors,” IEEE Instrumentation and Measurement Magazine, Vol. 4, No. 2, 2001, pp. 28-32.
 L. V. Panina and K. Mohri, “Magneto-Impedance Effect in Amorphous Wires,” Applied Physics Letters, Vol. 65, No. 9, 1994, pp.1189–1191. doi:10.1063/1.112104
 L. V. Panina, K. Mohri, T. Uchiyama and M. Noda, “Giant Magneto-Impedance in Co-Rich Amorphous Wires and Films,” IEEE Transactions on Magnetics, Vol. 31, No. 2, 1995, pp.1249-1260. doi:10.1109/20.364815
 M. Phan and H. Peng, “Giant Magnetoimpedance Materials: Fundamentals and Applications,” Progress in Materials Science, Vol. 53, No. 2, 2008, pp.323-420.
 H. Chiriac, M.Tibu, A. E. Moga, D. D. Herea, “Magnetic GMI sensor for detection of biomolecules”, J Magn. Magn. Mater., Vol. 293, 2005, pp: 671–676.
 B. Dufay, S. Saez, Ch. P. Dolabdjian, A. Yelon and D. Ménard, “Impact of Electronic Conditioning on the Noise Performance of a Two-Port Network Giant Magneto Impedance Magnetometer,” IEEE Sensors Journal, Vol. 11, No. 6, 2011, pp. 1317-1324.
 A. D. Bensalah, F. Alves, R. Barru′e, F. Simon and S. N. Kane1, “GMI Sensors Based on Stress-Annealed Iron Based Nanocrystalline Ribbons,” Sensors and Actuators A, Vol. 129, No. 1-2, 2006, pp: 142-145.
 R. Valenzuela, J. J. Freijo, A. Salcedo, M. Vazquez and A. Hemando, “A Miniature dc Current Sensor Based on Magneto Impedance,” Journal of Applied Physics, Vol. 81, No. 8, 1997, pp. 4301-4303. doi:10.1063/1.364809
 T.-A. óvári, H. Chiriac, C. S. Marinescu, F. J. Casta?o, M. Vázquez and A. Hernando, “Magneto-Impedance Response in Ring Shaped Amorphous Wires,” Sensors and Actuators A: Physical Journal, Vol. 91, No. 1-2, 2001, pp. 207-209. doi:10.1016/S0924-4247(01)00468-X
 J. Pongsakoron and C. Sirisathitkul, “Low-Cost Sensors Based on the GMI Effect in Recycled Transformer Cores,” Sensors, Vol. 8, No. 3, 2008, pp. 1575-1584.
 D. J. Mapps and L. V. Panina, “Magnetic Field Detector and a Current Monitoring Device Including Such a Detector”, US Patent No. 2004/0075431 A1, 2004.
 Y. W. Rheem, C. G. Kim, C. O. Kim and S. S. Yoon, “Current Senor Application of Asymmetric Giant Magnetoimpedance in Amorphous Materials,” Sensors and Actuators A: Physical Journal, Vol. 106, No. 1-3, 2003, pp. 19-21.
 M. Malátek, P. Ripka and L. Kraus, “Double-Core GMI Current Sensor,” IEEE Transactions on Magnetics, Vol. 41, No. 10, 2005, pp. 3703-3705.
 P. Ripka, “Current Sensors Using Magnetic Materials,” Journal of Optoelectronics and Advanced Materials, Vol. 6, No. 2, 2004, pp. 587-592.
 B. Han, T. Zhang, K. Zhang, B. Yao, X. Yue, D. Huang, H. Ren and X. Tang, “Giant Magnetoimpedance Current Sensor with Array-Structure Double Probes,” IEEE Transactions on Magnetics, Vol. 44, No. 5, 2008, pp. 605-608.
 B. Han, T. Zhang, D. Huang, X. Yue, Y. Zhou and M. Bi, “Giant Magnetoimpedance Current Sensor with Spiral Structure Double-Probe,” IEEE Transactions on Magnetics, Vol. 45, No. 4, 2009, pp. 1999-2002.
 K. Mohri, T. Uchiyama, L. P. Shen, C. M. Cai and L. V. Panina, “Amorphous Wire and CMOS IC-Based Sensitive Micro-Magnetic Sensors (MI Sensor and SI Sensor) for Intelligent Measurements and Controls,” Journal of Magnetism and Magnetic Materials, Vol. 249, No. 1-2, 2002, pp. 351-356. doi:10.1016/S0304-8853(02)00558-9
 Z. Zhan, L. Yaoming, C. Jin and X. Yunfeng, “Current Sensor Utilizing Giant Magneto-Impedance Effect in Amorphous Ribbon Toroidal Core and CMOS Inverter Multivibrator,” Sensors and Actuators A: Physical Journal, Vol. 137, No. 1, 2007, pp. 64-67.
 S. S. Yoon, P. Kollu, D. Y. Kim, G. W. Kim, Y. Cha and C. Kim, “Magnetic Sensor System Using Asymmetric Giant Magnetoimpedance Head,” IEEE Transactions on Magnetics, Vol. 45, No. 6, 2009, pp. 2727-2729.
 A. Boukhenoufa, Ch. Dolabdjian and D. Robbes, “High-Sensitivity Giant Magneto-Inductive Magnetometer Characterization Implemented with a Low-Frequency Magnetic Noise-Reduction Technique”, IEEE Sensors Journal, Vol. 5, No. 5, 2005, pp. 916-923.