The web pages in this section are devoted to electronic circuit and switching theory. Circuit analysis and filter design are the primary focus, although there are links to more general topics such as FFTs and root finders. Of particular interest is a complete port of the PASCAL software in Huelsman's book to C++. Also an implementation of Prof. Jiri Vlach's inverse Laplace Transform method from his book is here.
Although much of the material in these pages is devoted to analog design, logic design is also represented. In the section on switching theory you will find an application which you can use to simulate logic circuits and a paper on advanced methods in sequential circuit synthesis. Several design examples are presented using techniques explained in the paper.
Software for implementing various types of PLLs and a demo program displaying some critical signals in one implementation can be found at the above link.
Key parameters for Butterworth and Bessel filters can be found at Filters. I have found numerous errors in published filter data, so these parameters have been recalculated to assure full precision. An extended table is available for each case giving polynomials, pole locations, and component values for normalized filters.
Software for circuit analysis, along with working applications can be found here. Several papers on specific design topics are also provided.