Documentation

In high frequency PCB designs the impedance of a signal leading medium needs to be recognized. So it is convenient to determine the later width of a track in the layout already in the schematic. This should be possible for single signals or for signal classes as well. It is about the principle of how a strip line should be constructed. (StripLine).

Image: StripLine (Cross section)

Open in TARGET 3001! the Impedance calculator either in the dialog Edit signal wire (Double clock on a signal wire or [e] after having highlighted the signal) or in the dialog Edit signal classes (menu actions).

Image: The dialog: "Signalbahnen ändern"

The dialog "Signal-Klassen verwalten" Image: The dialog: "Signal-Klassen verwalten"

The following terms are of interest:

• The hugeness h of the dielectric agens the StripLine is embedded to (= the body of the PCB)
• The copper thickness t of the StripLine
• The permittivity ε_r of the dielectric agens

A certain Nenn-Impedanz Z required, needs resulting from the facts given the required track width w, which can be overtaken to the signal class as standard width.

If the StripLine is placed double (differential StripLine), the distance s between both tracks plays an additional role. The required spacing between the tracks is calculated and overtaken to the signal class definitions.

Image: The Impedance calculator gives the best track width and overtakes the value to a signal class.