Densign And Validation Of The Interface Circuit System In Digital Silicon Gyroscope

As an inertial device the high precision gyro play a key role in the field of military aerospace, digital interface circuit can effectively compensate the non-ideal factors of sensitive structures in mechanical gyroscope produced in the machining process,this article is geared to the needs of silicon micro mechanical gyro, make the design and validation for the digital interface circuit of system.Based on the C/V converting circuit, the Sigma-Delta AD converter oversampling technology, noise shaping technology and the working principle of the sampling filter technology, we make the design of interface circuit system for the MEMS gyro; Around the C/V converting circuit, modulator module and digital signal processing module, make the hardware and software design of the system. The design of modulator module is based on fourth-order feed-forward Sigma-Delta modulator, and make the design of a three-level cascade structure for modulator down sampling low-pass filter, the structure including CIC filter, CIC compensation filter and half band filter, and the realization of digital filtering is based on the C language and assembly language, programming and functional verification, transplanted to the digital signal processing module unit. The design of the Digital signal processing module is around digital signal controller, complete the transplantation floating-point library computing function, the development of industrial-grade RS485 and SPI interface, test the ADC module with 1 kHz bandwidth; after analyzing the structure of gyro, we make the micro mechanical gyro driving frequency as the input source with the method of all-temperature compensation. After the temperature compensation the bandwidth becomes 500 Hz. For the actual demand of user, we make the software development, make the CRC check for the output data to guarantee the accuracy, monitoring and printing the data of angular velocity in real time.Finally make the function and performance test of the interface circuit system, the signal-to-noise ratio of ADC module is 100.4 dB, effective digits is 16; The linearity and stability of digital silicon gyroscope system is 0.00042 and 16.48 ?/hr, all temperature zero bias stability is 207.8 ?/hr, achieve the demand of industrial.