Design of a Compact Calibration Platform for Characterization of Tunneling Magnetoresistive Sensors under Varying Temperatures

The temperature dependence of magnetic sensors' performance is a crucial factor that can impact measurement accuracy, necessitating precise characterization to compensate for errors caused by thermal drift. Previous research involved placing magnetic sensors in an oven to control temperature and measuring their responses to magnetic fields induced by current-carrying wires to determine temperature dependence. However, this approach was typically time-consuming and introduced errors due to the non-uniform magnetic field generated by the current-carrying conductor. In this study, we developed a compact calibration platform specifically designed to characterize magnetic sensors at different temperatures. The platform incorporates a thermoelectric cooler (TEC) to adjust the sensor's temperature. A temperature controller, implemented using a proportional-integral-derivative (PID) controller, regulates the temperature of the TEC, with a thermistor providing real-time temperature feedback. This compact platform enables temperature variations ranging from -25°C to 85°C for calibrating magnetic sensors at different temperatures. To validate the proposed design, we conducted sensitivity and offset drift characterizations of a commercial tunneling magnetoresistive sensor using the built platform. The obtained results aligned with the typical values provided in the sensor's datasheet, thus confirming the effectiveness of the proposed design.