Reliability Evaluation Method Of Electronic Circuits Based On Tolerance Analysis And Its Application

Tolerance exists everywhere.Electronic components may have tolerance values during service periods,and even cause failure because of that,due to factors such as fluctuations in production processes,working environment,stress excitation,and degradation.Tolerance is one of the key factors determining the performance of electronic circuits and one of the key factors determining the cost of electronic circuit design.It can be seen that it is necessary to carry out scientific tolerance analysis of electronic circuits in the design stage.On the other hand,with the rapid increase of the degree of integration of electronic circuits and the level of manufacturing technology,the reliability of large-scale electronic circuits has always been a research hotspot and a difficult problem in the field of electronic circuits.Tolerance analysis and reliability analysis of electronic circuits are closely related.Tolerance analysis helps designers know the key elements of input uncertainty factors and lay the foundation for reliability analysis.Comparably,reliability is the key target of tolerance analysis.Based on the theory of tolerance analysis,this paper explores electronic circuit modeling and functional reliability simulation methods,and develops reliability assessment and design methods based on tolerance analysis.The specific research contents and innovations are as follows:(1)Aiming at the offset fault in electronic circuit tolerance fault,a simulation-based fault quantitative impact analysis method is proposed.First,the technical points and analysis flow of the fault quantitative impact analysis method are described,and then the research on the offset fault is carried out.Subsequently,the advantages of using the Saber platform to perform quantitative analysis of faults are discussed,and electronic component modeling tools and modeling methods are discussed.Next,this paper discuss the common offset faults and their fault mechanisms in electronic circuits,and solve the problems of fault injection,quantification of fault criteria and simulation of fault quantification effects.Finally,the proposed method is applyed to simulate the 1553 B bus module and to analyze the fault quantitative impact.(2)Aiming at the soft faults in electronic circuit tolerance faults,a reliability evaluation method based on sensitivity analysis is proposed.Firstly,the current mainstream sensitivity analysis methods are analyzed.Then,the mathematical modeling method of electronic circuit considering degradation is introduced,and the sensitivity-based circuit degradation model is obtained.In order to measure the degradation rate of the output characteristics of electronic circuits,the reliability index of electronic circuits is discussed.Finally,the degradation tolerance analysis of the Sallen-Key bandpass filter is developed based on the sensitivity analysis.(3)A reliability design method based on tolerance analysis is proposed,with the goal to minimize the cost of electronic circuit design while meeting reliability requirements.Firstly,the output characteristics and constraints of electronic circuits are analyzed,and then the sensitivity simulation analysis method based on orthogonal design is introduced.Secondly,based on the sensitivity analysis conclusions,Monte Carlo simulation and regression analysis are carried out to determine the equations of key component cost and tolerance.Subsequently,the objective circuit and the constraint conditions of the electronic circuit based on the optimal cost are given to determine the optimal tolerance scheme.Finally,the above method is used to optimize the reliability of the forward switching power supply in Chapter 3.