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A Modulation Method for Tunnel Magnetoresistance Current Sensors Noise Suppression
Shuaipeng Wang1, Haichao Huang1, Ying Yang2
1Beijing Smart-Chip Microelectronics Technology Co., Ltd., Beijing 102299, China.
Micromachines
|March 28, 2024
Summary
This study introduces a modulation-demodulation technique to improve weak current detection accuracy in tunnel magnetoresistance (TMR) sensors by filtering out low-frequency noise. The method enhances signal-to-noise ratio and resolution for precise measurements.
Area of Science:
- Electrical Engineering
- Sensor Technology
- Signal Processing
Background:
- Low-frequency noise from tunnel magnetoresistance (TMR) current sensors and ambient magnetic fields degrades weak current detection accuracy.
- Accurate measurement of weak currents is crucial in various electronic applications.
Purpose of the Study:
- To propose and validate a high-resolution modulation-demodulation test method for TMR current sensors.
- To mitigate the impact of low-frequency noise and stray magnetic fields on weak current measurements.
Main Methods:
- Developed a Simulink model for the modulation-demodulation test method.
- Implemented and tested the method in both time and frequency domains.
- Modulated and demodulated the measurement signal to shift noise to the high-frequency band for filtering.
Main Results:
- Achieved a TMR current sensor nonlinearity as low as 0.045%.
- Demonstrated an enhanced signal-to-noise ratio (SNR) of 77 dB.
- Attained a heightened resolution of 100 nA.
Conclusions:
- The modulation-demodulation test method effectively reduces low-frequency noise impact on TMR current sensors.
- This technique can be extended to improve other types of resistive devices.
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