A non-invasive thermal drift compensation technique applied to a spin-valve magnetoresistive current sensor

• Published in: Sensors (Basel, Switzerland) Vol. 11; no. 3; pp. 2447 - 2458
• Main Authors: Sánchez Moreno, Jaime, Ramírez Muñoz, Diego, Cardoso, Susana, Casans Berga, Silvia, Navarro Antón, Asunción Edith, Peixeiro de Freitas, Paulo Jorge
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-03-2011; Molecular Diversity Preservation International (MDPI)
• Subjects: Digital signal processors; Electric currents; Electric Impedance; electrical current measurement; Equipment Design; Magnetics - instrumentation; Magnetics - methods; magnetoresistance sensor; Power supply; Ruthenium - chemistry; Sensors; spin-valve sensor; Temperature; temperature compensation; electrical current measurement; temperature compensation; magnetoresistance sensor; spin-valve sensor
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s110302447

A compensation method for the sensitivity drift of a magnetoresistive (MR) Wheatstone bridge current sensor is proposed. The technique was carried out by placing a ruthenium temperature sensor and the MR sensor to be compensated inside a generalized impedance converter circuit (GIC). No internal modification of the sensor bridge arms is required so that the circuit is capable of compensating practical industrial sensors. The method is based on the temperature modulation of the current supplied to the bridge, which improves previous solutions based on constant current compensation. Experimental results are shown using a microfabricated spin-valve MR current sensor. The temperature compensation has been solved in the interval from 0 °C to 70 °C measuring currents from -10 A to +10 A.