Research And Implementation Of Analog Circuit Fault Simulation Injection Technology

Analog circuit fault simulation is an important supplementary means in analog circuit design, which can analysis and verify the robustness and the fault tolerance of circuit system and can provide the basis for fault diagnosis and improving the system design. Meanwhile, it is also an important step in the logical test. A great number and diversity of analog circuit fault give rise to fault model in abundance accordingly.As a result, the question of a large-scale analog circuit fault simulation which needs to be solved urgently is how to make effective organization and management, to quickly find matching fault model, and even to complete fault injection flexibly and automatically.This paper researches on fault simulation which aims at analog circuit, and takes a certain type of analog circuit simulation system as its application background. The method of analog circuit fault simulation is proposed and the simulation of analog circuit fault is realized. Further a multi-fault injector is designed and implemented, which has the ability of batch injecting for the same fault type automatically. The main research contents in the paper are as follows:Firstly, this paper summarizes the theoretical basis, the methods and application technology of analog circuit fault simulation. To be specific, it expounds the concept and working principle of analog circuit fault simulation, introduces of the simulation technology and principle of Spice engine applied widely, and analyzes, the fault modeling technique and the fault injection technique, the core technology of analog circuit fault simulation. Based on these theories and methods, this paper mainly studies on application technology and implementation for the project requirements.Secondly, a single fault automatic injection method based on the equivalent circuit is proposed combined with analog circuit simulation system in the project. The method build the fault model libraries which conform to the simulation system, and the fault model will be automatically injected into the analog circuit system through the fault injector. The equivalent circuit method is adopted to establish analog circuit fault model. The fault automatic injection method is put forward. The overall frame of the analog circuit fault simulation is designed to support automatic injection from the fault model library and to set the way of fault injection manually. Based on the component model and the fault model library, using Spice engine, the technology has realized the automatic fault injection and fault simulation. The method is verified by an example.At last, in order to improve the capacity of analog circuit fault simulation, based on the fault simulation method above, this paper further puts forward the multiple fault injection algorithm and implements a multi-fault injector. The pre-processing of netlist file will flatten the stratified circuit system which includes sub-circuits. The multi-fault injection algorithm is used to achieve mass fault injection. The multi-fault injector is designed and implemented, and we can verify the availability of the proposed fault injector by an instance.