Asymmetric Stripline Calculations - National Instruments Graphical User Interface Ultiboard User Manual

Chapter 6 PCB Calculators
If you chose User Defined Zo in the previous step, the Per Length Unit and the
Note
Differential Impedance are the only values that appear in the Calculation Results area
of the PCB Differential Impedance Calculator dialog and the Results tab when you click
Calculate.

Asymmetric Stripline Calculations

NI Ultiboard User Manual
4. Click Calculate. Results of the calculation appear in the Calculation
Results area. They also appear in the Results tab of the Spreadsheet
View.
5. Click Close to close the PCB Differential Impedance Calculator.
Centered Stripline Differential Impedance Equations
The equations used to perform the centered stripline differential impedance
calculations are:
Z0 = 60*ln(4*(2*H+T)/(0.67*3.1415926*(0.8*W+T)))/sqrt(Er)
Tpd = 84.66667*sqrt(Er)
C0 = Tpd/Z0
L0 = C0*Z0*Z0
Zdiff = 2*Z0*(1-0.347*exp(-2.9*S/(2*H+T)))
Complete the following steps to perform asymmetric stripline differential
impedance calculations:
1. Select Tools»PCB Differential Impedance Calculator.
2. Select Asymmetric Stripline in the Type drop-down list.
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