Novel methods for circuit worst-case tolerance analysis

The method, presented by E. R. Hansen (see SIAM J. Numer. Anal., vol. 29, no. 5, p. 1493-1503, 1992) for solving interval linear equations, is improved to meet the requirements of circuit worst-case tolerance analysis. Based on the solutions of interval linear equations, an analytic algorithm and an accurate algorithm are constructed. It is shown that the performances of the two algorithms are complementary: the analytic algorithm runs faster than the accurate algorithm, but has more interval expansion error. Techniques for AC tolerance analysis, time-domain tolerance analysis and DC tolerance analysis are discussed respectively. Some examples and comparisons are given.