# Utilities

For use with High-Speed Digital Design: A Handbook of Black Magic

You must have the MathCad application, version 13 or later, for these files to function. If you live in like, Bhutan, or something, and need older-version source code, talk to the webmistress at: info03@sigcon.com.

The following MathCad scripts accompany the book High-Speed Digital Design: A Handbook of Black Magic. They are taken directly from Appendix C. Additional examples not in the book are included in these files. The scripts are provided in MathCad syntax, and also in the form of .pdf files in case you want to just see the equations so you can port them to another brand of mathematical spreadsheet.

The .zip file includes a simple short-line transmission line simulator that incorporates the effects of source impedance, load impedance, transmission line delay, characteristic impedance, and risetime of the driving waveform. It does not incorporate skin-effect or dielectric loss. If you want that, look here in the download library for the book :High-Speed Signal Propagation: More Black Magic.

## Derivations

The following articles present the motivation behind various equations used in the book:

• Skin Effect Calculations: Special discussion on derivation of Skin Effect Calculations in High-Speed Digital Design: A Handbook of Black Magic.
• Resistance: Concerning the derivation on page 414 of the equation for calculating the DC resistance of power planes based on the diameters of two contact points space at X amount of distance. (newsletter v1-11)
• Ground-bounce calculations: On page 62 of the High-Speed Digital Design Text… where does the factor of 1.52 come from? (newsletter v1-12)
• Equiv. Circuit Source Impedance: What is the true source impedance of the equivalent circuit at figure 1.6 (page 13)? (newsletter v2-09)
• Via Capacitance: On page 257, formula [7.6] for the capacitance of a via is a crude approximation--I've now got some better material. (newsletter v5-09)
• Via Inductance: On page 259, formula [7.9] glosses over the location of the signal return current associated with the via. A full discussion of the issue is now available. (newsletter v6-04)