A Chopper-Stabilized Lateral-BJT-Input Interface in 0.6µm CMOS for Capacitive Accelerometers

📋 论文概要

该论文提出了一种用于电容式MEMS加速度计的斩波稳定接口电路，采用0.6µm CMOS工艺中的横向双极型晶体管（BJT）作为输入级，以降低低频闪烁噪声。实现了接近直流的微重力分辨率，满足了高精度惯性导航等应用需求。

💡 主要创新点

• 采用横向BJT输入级替代传统MOSFET，显著降低1/f噪声，提升低频分辨率。
• 结合斩波稳定技术，消除低频噪声和失调，实现近DC的微g级加速度检测。
• 在0.6µm标准CMOS工艺中集成横向BJT，无需额外工艺步骤，兼顾低成本与高性能。

🏷 关键词

📄 原文摘要

There has been increasing demand for low-cost small-size highprecision MEMS accelerometers with micro-gravity resolution at very low frequencies in applications ranging from GPS-augmented inertial navigation to distance measurement systems [1]. The resolution of capacitive micro-g accelerometers interfaced with lowcost CMOS circuits is typically limited by the flicker noise of the input transistors at very low frequencies. Although there have been a few reports of micro-g resolution at input frequencies higher than 10Hz [1-4], achieving near DC micro-g resolution has proven to be difficult with small-size micromechanical sensors suitable for consumer applications. We present a prototype lateralPNP (LPNP) BJT interface IC for an SOI capacitive accelerometer with a measured resolution of 6.3μg/√Hz and an output noise floor of -118dBV/√Hz for a gain of 204mV/g at extremely low frequencies. The resolution is improved by further reducing the

👥 作者与机构

Dongning Zhao, M. Faisal Zaman, Farrokh Ayazi

Georgia Institute of Technology, Atlanta, GA