Anti-Power Supply Disturbance Optimization Design and Self-Correction Measurement Method of TMR Current Sensor

The tunnel magnetoresistance current sensor is susceptible to power supply disturbances, resulting in a decrease in measurement accuracy or even failure. In this paper, the influence of power supply voltage change on tunnel magnetoresistance current sensor is studied, and a self-correction measurement method of power supply disturbance based on voltage feedback is proposed to suppress the interference effect of power supply disturbance. A self-correction measurement method of power supply disturbance based on voltage feedback and its self-correction sensor model are proposed. By synchronous sampling of power supply voltage signal and sensor monitoring signal, and using self-correction algorithm for synchronous signal processing, the interference suppression problem of power supply voltage disturbance is solved. A voltage feedback tunnel magnetoresistance current sensor prototype was developed and an experimental platform was built for experimental verification. The experimental results show that when the power supply only contains ripple, the measurement error of the sensor without self-correction measurement method is less than 1%, while the measurement error after self-correction measurement method is about 0.11%, which effectively suppresses the interference of ripple. In the range of ±10% change of working power supply, the measurement error before correction is about 9.55%, while the measurement error after correction is less than 0.49%, which effectively suppresses the interference effect of power supply voltage disturbance on the measurement results, and proves the correctness and effectiveness of the proposed optimization method.