A 4mW 45pT/√Hz Magnetoimpedance-Based ΔΣ Magnetometer with Background Gain Calibration and Short-Time CDS Techniques

📋 论文概要

该论文提出了一种基于磁阻抗效应的ΔΣ磁力计，采用背景增益校准和短时相关双采样技术，实现了低功耗(4mW)和低噪声(45pT/√Hz)的数字输出，解决了传统磁力计增益随环境变化的不稳定性问题。

💡 主要创新点

• 提出背景增益校准技术，无需中断测量即可实时校准增益，增强系统鲁棒性。
• 采用短时相关双采样(CDS)技术，在低功耗下有效降低低频噪声。
• 基于磁阻抗效应的ΔΣ架构实现数字输出，兼具高精度和低功耗特性。

🏷 关键词

📄 原文摘要

Aichi Steel, Tokai, Japan 1 2 Low-noise, low-power digital-output magnetometers are essential for various applications, including security-gate systems, non-destructive inspections, and geomagnetic and biomagnetic measurement systems. To ensure accurate measurements, it is crucial to maintain the robustness of the conversion gain from the input magnetic field to the digital-output signal. This paper presents a 3.96mW ΔΣ magnetometer with an input-referred noise of 45pT/√Hz. Gain robustness is realized via a proposed background gain calibration and low-power CDS techniques. An FoM for the proposed magnetometer is 1.25fW/Hz, setting a new benchmark for energy efficiency among state-of-the-art designs with digital output, while maintaining low noise characteristics. Figure 3.5.1 shows the overall block diagram of the proposed magnetoimpedance (MI)based ΔΣ magnetometer. The sensor head is based on an MI element, which is composed

👥 作者与机构

Ippei Akita1, Shunichi Tatematsu2

AIST, Tsukuba, Japan