Research On The Interface Circuit Integration For Quartz Gyroscopes With Digital Output

As an angular velocity measuring device,quartz gyro has a wide range of applications in defense,aerospace and commercial fields.Through years of efforts,our country has realized the integration of analog output chips for quartz gyro interface circuits,and it is urgent to solve the problem of digital output chip integration.Research on digital chip integration technology of quartz gyro interface circuit to realize high-precision quartz gyro interface digital ASIC chip with digital output,on-chip digital temperature compensation and batch measurement and adjustment function is great significance to the development of quartz gyro.The research on digital chip integration technology of quartz gyro interface circuit mainly has the following problems: phase noise,aliasing noise and quantization noise of digital drive circuit system have significant influence on detection circuit.The stability model of analog drive circuit is no longer applicable.After the digitalization of the circuit,new noise sources which needs to by ananlyzed deeply are introduced.However,no relevant research is reported so far,and the optimal design of the high-precision digital detection circuit is limited.The mass application of quartz gyros has been hindered because of the high-precision digital temperature compensation and batch mesurment and adjustment problems.Firstly,according to the principle of quartz gyro system,the equivalent electrical model of sensitive structure is obtained.Based on this,the behavioral level model of the digital ASIC chip of quartz gyro interface is given.The index of each main module of the interface circuit is determined by simulation.The requirements of the quartz gyro system for circuit design is carified.Secondly,the stability of the digital gyro digital drive circuit is studied in depth.On the one hand,the phase noise model of the digital driving circuit is established,the influence of phase stability on the output precision of the detection circuit is obtained,and the phase stability of the digital driving circuit is optimized,thereby reducing the influence of the phase stability of the digital driving circuit on the digital detecting circuit.On the other hand,the digital drive circuit noise and PI control circuit model are established,and the relationship between the amplitude stability and the output accuracy of the detection circuit is obtained.The optimization of the amplitude stability of the digital drive circuit is carried out to reduce the influence of caused by amplitude stability of the digital drive circuit.This study laid the foundation for the design of quartz gyro digital drive circuits.Thirdly,based on the noise introduced by the quartz gyro digital drive circuit and the noise generated by the digital detection circuit itself,the full noise model of the quartz gyro digital detection circuit is established,and the influence of the digital detection circuit noise on the output bias stability is obtained.The reseach results are significant to the design of low noise pre-stage charge detection circuit,demodulation circuit and high-precision analog-to-digital conversion circuit.Finally,the temperature characteristics of the sensitive structure of quartz gyro are studied,and the relationship between the parameters of driving signal frequency,output zero and zero stability and temperature is obtained.An on-chip high-precision digital temperature compensation circuit is designed.A batch measurement and adjustment scheme was proposed.Through a single temperature rise and fall test,batch calibration and compensation of parameters such as output zero and full temperature stability of multiple quartz gyro machine systems were realized.The high-precision digital temperature compensation problem and the batch measurement and adjustment problem of the quartz gyro are solved.Based on the above research,the 0.35?m BCD-MOS process parameters and design rules are used to design and implement a high-precision quartz gyro interface digital ASIC chip with digital output,on-chip digital temperature compensation and batch measurement and adjustment function.The chip area is 5mm×5mm,and the quartz gyro sensitive structure provided by Institute is used for the whole machine test.The zero-stability of the quartz gyro machine is 2.9°/hr(1?),and the stability of Allan variance is 1°/hr.After compensation,the zero temperature drift of the full temperature zone is 16°/hr,the angular-random-walk is 0.022°/?hr,and the nonlinearity reaches 0.035% within the range.The quartz gyro digital interface circuit chip and the whole machine test result verify the correctness of the theoretical model and chip design.