Temperature stability and compensation of AMR sensors in practical applications

Abstract

Magnetic field sensors are widely used in smart electronic systems for transportation, structural health monitoring, current sensing, geomagnetic navigation, and other applications. Among various sensor types, anisotropic magnetoresistance (AMR) sensors are often selected for their compact size, high sensitivity, and low cost. However, their performance is significantly affected by temperature-induced drift in magnetic field measurements. This study evaluates the temperature stability of three AMR sensors - LSM303AGR, LIS3MDL, QMC5883L - and a fluxgate sensor, DRV425. Results show that LSM303AGR demonstrates the best temperature stability in magnetic fields under 100 mu T, with an average drift of 24.8 nT/K, and a sensitivity drift of -488 ppm/K, while LIS3MDL is suitable for measuring stronger fields due to its linear temperature characteristic despite a higher drift of 152.9 nT/K. Sensor measurement drift amounts to 12 % to 76 % of magnetic field threshold over a 50 degrees C range in practical reference application (10 mu T), but algorithmic compensation using application-specific or diverse datasets can reduce drift to as low as 4.9-7.9 % of the reference threshold in fields under 100 mu T. These findings highlight the importance of tailored compensation strategies when using AMR sensors for reliable longterm magnetic field monitoring.

Magnetic field sensors are widely used in smart electronic systems for transportation, structural health monitoring, current sensing, geomagnetic navigation, and other applications. Among various sensor types, anisotropic magnetoresistance (AMR) sensors are often selected for their compact size, high sensitivity, and low cost. However, their performance is significantly affected by temperature-induced drift in magnetic field measurements. This study evaluates the temperature stability of three AMR sensors - LSM303AGR, LIS3MDL, QMC5883L - and a fluxgate sensor, DRV425. Results show that LSM303AGR demonstrates the best temperature stability in magnetic fields under 100 mu T, with an average drift of 24.8 nT/K, and a sensitivity drift of -488 ppm/K, while LIS3MDL is suitable for measuring stronger fields due to its linear temperature characteristic despite a higher drift of 152.9 nT/K. Sensor measurement drift amounts to 12 % to 76 % of magnetic field threshold over a 50 degrees C range in practical reference application (10 mu T), but algorithmic compensation using application-specific or diverse datasets can reduce drift to as low as 4.9-7.9 % of the reference threshold in fields under 100 mu T. These findings highlight the importance of tailored compensation strategies when using AMR sensors for reliable longterm magnetic field monitoring.