Calculating PCB Track Impedanc...

Calculating PCB Track Impedance FormulasCalculation of PCB Track Impedance
by Andrew J Burkhardt, Christopher S Gregg and J Alan Staniforth

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he use of high-speed circuits requires PCB tracks to be designed with controlled (characteristic, odd-mode, or differential) impedances. Wadell[1] is one of the most comprehensive sources of equations for evaluating these impedances. This source includes many configurations including stripline, surface microstrip and their coplanar variants. The IPC publication, IPC-2141[2], is another source of equations, but has a smaller range of configurations, similar to those presented in IPC-D-317A. However, for some configurations there are differences between the equations given in these publications. The authors believe that it is now opportune to examine the origin of the equations and to
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