应用于MEMS陀螺仪的SoC设计

SoC Design for MEMS Gyroscope

摘要:

为了解决微电子机械系统(MEMS)陀螺仪体积较大、冗余的计算资源浪费等问题,对Cortex-M3内核的数据处理能力及总线架构进行了研究,设计了一款应用于MEMS陀螺仪的智能化、小型化、低功耗的片上系统(SoC)；通过分析温度对陀螺输出信号的影响,对MEMS陀螺温度误差的智能化补偿方式进行了研究,采用以Cortex-M3为核心与电容/电压转换电路、模数转换器(ADC)等模块进行集成化设计的方法,在实现同样功能的情况下减小了陀螺体积；结合MEMS陀螺仪对信号处理资源的要求对存储空间及通信接口进行配置,采用0.18 μｍ BCD加工工艺对SoC进行设计制作；测试结果表明,针对MEMS陀螺仪进行匹配设计的SoC对陀螺输出信号进行温度补偿处理后,全温度区间(-40 ℃～85 ℃)零偏变化量由3.147°/s降低到0.035°/s,显著提升了MEMS陀螺仪的全温测量精度。

Abstract:

In order to solve the problems of large volume and redundant computing resource waste of MEMS gyroscope, the data processing capability and bus architecture of Cortex-M3 core are studied, and an intelligent, miniaturized and low-power system-on-chip (SoC) for MEMS gyroscope is designed; By analyzing the influence of temperature on the output signal of the gyroscope, the intelligent compensation method of the temperature error of MEMS gyroscope is studied. The method of integrated design with Cortex-M3 as the core, capacitance/voltage conversion circuit, analog-to-digital converter (ADC) and other modules is adopted to reduce the volume of the gyroscope under the same function; Configure the storage space and communication interface according to the requirements of MEMS gyroscope for signal processing resources, using 0.18μm BCD processing technology is used to design and manufacture the SoC; The test results show that after the SoC, which is designed for the matching of MEMS gyroscope, performs temperature compensation processing on the output signal of the gyroscope, the zero deviation variation in the full temperature range (-40 ℃~85 ℃) is reduced from3.147 °/s to0.035 °/s, significantly improving the full temperature measurement accuracy of MEMS gyroscope.