A ΔΣ Interface for MEMS Accelerometers Using Electrostatic Spring-Constant Modulation for Cancellation of Bondwire Capacitance Drift

📋 论文概要

该论文提出了一种用于MEMS加速度计的ΔΣ接口，通过静电弹簧常数调制来抵消键合线电容引起的偏移漂移，从而提升传感器精度。

💡 主要创新点

• 利用静电弹簧常数调制技术，动态抵消键合线电容导致的寄生效应，减少偏移漂移。
• 将ΔΣ调制与MEMS传感器接口结合，实现高精度数字输出，无需传统工厂校准。

🏷 关键词

📄 原文摘要

Robert Bosch, Palo Alto, CA 1 2 Precision accelerometers are used in a variety of automotive applications, navigation systems, and low-level vibration-monitoring systems. Currently, these sensors are factory-calibrated to null their input offset. However, the residual offset drifts mainly due to thermal and mechanical stress and humidity. As a result, the offset accuracy of high-end MEMS accelerometers is specified on the order of ±100mg [1]. With continuously increasing precision requirements, it is desirable to develop new techniques that address post-calibration drift. In this paper, we describe an accelerometer interface that continuously measures and cancels offset drift due to change in parasitic capacitance of the bondwires in a system-in-package-type MEMS accelerometer [2]. The proposed technique reduces the bondwire offset of the measured prototypes by 41dB down to 6.24mg. The accelerometer used in this work employs a capacitive MEMS sensor element and a CMOS chip connected wi

👥 作者与机构

Pedram Lajevardi1, Vladimir Petkov2, Boris Murmann1

Stanford University, Stanford, CA