TOLERANCE ANALYSIS AND DESGIN OF ELECTRONIC CIRCUITS

Abstract

On tolerance analysis, a new method of tolerance analysis based on hybrid matrix analysis of circuits is proposed. The proposed method can be applied to both linear and nonlinear networks including all types of electronic components. It extends the range of tolerance analysis of electronic circuits and has special significance for tolerance analysis with large-change values of circuit parameters. In addition, it enables reduction of computational workload for analysis where repeated assessments of the performance of the circuit are carried out when only some of the component values are changed such as in Monte Carlo analysis. On tolerance design, a new tolerance assignment method to determine the most economic set of component tolerances for mass-produced electronic circuits is proposed. The method makes use of orthogonal array for optimization. A new approach to further speed up computation and simplify the process of optimization, called sequential strategy method, is also proposed. The method makes use of Margin Function which is developed in the thesis to determine the initial tolerance region that fits in the region of acceptability and cost function to determine the set of tolerances which gives the optimal unit cost. The use of Margin Function has further simplified and sped up the process of tolerance assignment. The proposed tolerance assignment method has the advantages that it places no restriction upon parameter density functions, it is faster and provides better convergence, and it is able to determine the largest tolerances of parameters admissible for given design specifications.