Qualitative analysis of analog circuits with expanded node and loop equations

Qualitative analysis is a powerful tool for analyzing analog circuits at the beginning of a design process as well as for educational purposes. Using an expanded form of circuit description and solving qualitative equations with respect to correlations of values presents a reliable method. Experience has shown however, that with conventional network analysis methods there is a loss of information while transforming into the qualitative domain. By producing additional linearly dependent node and loop equations this problem can be avoided. This paper takes a closer look at the transformation of equation systems into the qualitative domain, presents efficient algorithms to solve the arising problems and discusses the complexity of such algorithms