Tolerance Analog Circuit Analysis Technology Application And Implementation

It is not persuasive to study on elements’academic parametric value with no deviation. Considering the stochastic factors of circumstance, tolerance analysis is better at modeling actual analog circuits, and providing reliable data resource for algorithm analysis.The key works of this paper include:1. Tolerance analysis and design on analog circuits of fault modeling. Regularly, modeling analog circuits indicates the analysis on linear passive elements. Combined with the definition of hard fault and soft fault, the model objects are extended to MOSFET and op-amp. Furthermore, these methods are introduced into tolerance analysis, which is emphasized on single variable Monte-Carlo as well as multivariable Monte-Carlo.2. Secondary development of HSPICE. Tolerance analysis is inadequate at overmuch simulation number of times, enormous output results, intense repetitive operation. Taking advantage of HSPICE’s documentary input, documentary output, simple circuit modification, complete element models, secondary development of HSPICE is designed:automatic simulation platform for no tolerance analog circuits and tolerance analog circuits.3. Fault algorithm implementation on tolerance analog circuits. Based on these two automatic simulation platforms, fault algorithms are improved, which indicate fault diagnosis algorithm of CHMM, fault prediction algorithm of ARMA and GM, and fault detection algorithm of SPRT in order to agree with actual condition. Then relying on VC++and MATLAB, every algorithm module is realized. Finally, by the example of Sallen-Key filter, analysis of every algorithm module is illustrated. 4. Verification on fault algorithms. In the experimental target of frequency amplitude and impulse response, the measured data to the output node voltage verifies the feasibility of the algorithm modules by designing the experimental circuit of Sallen-Key filter.The verification shows that the system works well and acquires the tolerance analysis result of analog circuits by convenience and efficiency. The established system can provide the reliable simulation data for the research of fault algorithm. The diagnosis module could have diagnosed faults, as well as the prediction module having predicted right trend and the detection module having tested failures.