Tunneling magnetoresistive (TMR) magnetic sensors are broadly applied in various fields. However, to further improve the limit of detection (LOD), it is highly desirable to realize and calculate the noise limits of such sensor systems. Thus, techniques for noise elimination can be developed. In this paper, we propose an equivalent magnetic noise model to describe the LOD of a TMR magnetometer by considering intrinsic noise sources in the TMR sensing element and readout electronics. According to the model, the contribution of each noise source can be directly obtained. Therefore, the LOD of the magnetometer can be established theoretically. Moreover, the predicted detectivity of 390 pT/ $\surd $ Hz is also demonstrated by the experimental results. The model is applicable to all kinds of TMR sensors with a “Wheatstone bridge” configuration.

中文翻译：

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隧道式磁阻磁强计的等效磁噪声分析

隧道磁阻（TMR）磁传感器广泛应用于各个领域。然而，为了进一步提高检测限 (LOD)，非常需要实现和计算此类传感器系统的噪声限制。因此，可以开发用于噪声消除的技术。在本文中，我们通过考虑 TMR 传感元件和读出电子设备中的固有噪声源，提出了一个等效磁噪声模型来描述 TMR 磁力计的 LOD。根据模型，可以直接得到每个噪声源的贡献。因此，理论上可以建立磁力计的LOD。此外，实验结果也证明了 390 pT/$\surd $Hz 的预测检测率。该模型适用于具有“惠斯通电桥”配置的各种TMR传感器。