硅微陀螺仪低功耗数字相敏解调ASIC设计

Low Power Consumption Digital Phase-Sensitive Demodulation ASIC Design for Silicon Microgyroscopes

为了避免相敏解调引入的1/f噪声,同时进一步提高集成度、降低功耗,实现高精度硅微陀螺仪的全数字输出,设计了一种硅微陀螺仪数模单片集成电路。首先,针对已有的Σ-Δ模数转换器(ADC)交流量化方案,设计了一种基于数字滤波系统的信号链预处理电路;其次,研究了数字滤波系统和乘法解调方案在有限版图面积中低功耗的硬件电路的实现方法,在IC设计平台上完成了包括前端信号链预处理电路、乘法解调模块、实时温度测量模块及串行接口(SPI)通信模块的设计与验证,并采用TSMC 0.35μm工艺进行了流片。实验结果表明,硅微陀螺仪输出零偏不稳定性为0.38°/h,角度随机游走为0.05°/h^(1/2),零偏稳定性为3.4°/h,数字部分功耗为15.8 mW。实现了高精度硅微陀螺仪的低功耗和低噪声的全数字正交解调输出,提高了硅微陀螺仪的集成度和实用性。

In order to avoid the 1/f noise introduced by phase-sensitive demodulation,meanwhile further improve the integration level and reduce the power consumption,and realize the all-digital output of the high-precision silicon microgyroscope,a digital analog monolithic integrated circuit of the silicon microgyroscope was designed.First,for the existing Σ-Δ analog-to-digital converter(ADC) alternating quantization scheme,a signal chain preprocessing circuit based on digital filter system was designed.Then,the realization methods of the low power consumption hardware circuit of the digital filter system and multiplication demodulation scheme in the limited layout area were studied.The design and verification of the front-end signal chain preprocessing circuit,multiplication demodulation module,real-time temperature measurement module and serial peripheral interface(SPI) communication module were completed on the IC design platform,and the chip was taped out by TSMC 0.35 μm technology.The experimental results show that the silicon microgyroscope has an output zero bias instability of 0.38°/h,an angle random walk of 0.05°/h^(1/2),a zero bias stability of 3.4°/h and the digital part power consumption is 15.8 mW.The full digital quadrature and demodulation output with low power consumption and low noise of the high-precision silicon microgyroscope is realized,and the integration level and practical application of the silicon microgyroscope are improved.