单片集成MEMS陀螺数字闭环接口ASIC电路设计  

Design of digital closed-loop monolithic integrated ASIC interface circuit for MEMS gyroscope

作　　者：童紫平 龙善丽 张慧 唐兴刚 吴传奇 贺克军 TONG Ziping;LONG Shanli;ZHANG Hui;TANG Xinggang;WU Chuanqi;He Kejun(East China Institude of Photo-electron IC,Su Zhou 215163,China)

机构地区：[1]华东光电集成器件研究所,苏州215163

出　　处：《中国惯性技术学报》2020年第4期505-509,共5页Journal of Chinese Inertial Technology

基　　金：装备预研重点基金项目(61405170111)。

摘　　要：为提高MEMS陀螺的线性度和稳定性,设计了适用于电容式MEMS陀螺的数字式双闭环接口电路。首先,概括了接口电路的系统结构,包括电容/电压转换电路、高精度模数转换器、数字信号处理等模块。然后,设计了基于自动增益控制的陀螺驱动闭环控制系统,并分析了驱动闭环稳定性条件,为驱动闭环系统的快速调试提供理论指导。最后,提出了一种基于四阶机电结合∑△调制器原理的陀螺敏感闭环检测系统。接口电路在0.18μm高压CMOS工艺平台上完成流片,并且与MEMS陀螺结构封装在一个管壳中进行测试验证。测试结果表明本接口电路的优越性能:在±500°/s量程下陀螺非线性度达到52.8 ppm,陀螺零偏不稳定性为0.58°/h(Allan方差),角度随机游走等于0.07°/√h,满足高性能MEMS陀螺对高线性度、高稳定性接口电路的应用需求。In order to improve the linearity and stability of MEMS gyroscope, a digital dual closed loop interface circuit for capacitive MEMS gyroscope is designed. Firstly, the system structure is summarized, including C/V conversion circuit, high precision ADC, digital signal processing module and so on. Then the drive closed-loop control system based on automatic gain control(AGC) is designed, and the loop stability conditions are analyzed for the quick commissioning of the drive closed-loop system. Finally a force-feedback architecture based on fourth-order electromechanical sigma delta modulator(EM-∑△M) for gyroscope sense mode is proposed. The interface circuit is implemented in 0.18 μm HVCMOS technology, and the ASIC is bonded in one package with the gyroscope structure for a better performance. Measurement results indicate the superior performance of the gyroscope, with a bias instability of 0.58°/h, a angular random walk of 0.07°/√h, and a nonlinearity of 52.8 ppm under a full-scale range of ±500°/s, which meets the application requirements of high-performance MEMS gyroscopes.

关 键 词：MEMS陀螺 接口电路 ∑△调制器 自动增益控制 

分 类 号：TN453[电子电信—微电子学与固体电子学]