Chapter 6
PCB Calculators
©
National Instruments Corporation
6-5
Centered Stripline Equations
The equations used to perform the centered stripline 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
Asymmetric Stripline Trace Calculations
Complete the following steps to perform asymmetric stripline trace
calculations:
1.
Select
Tools»PCB Transmission Line Calculator
.
2.
Select
Asymmetric Stripline
in the
Type
drop-down list.
3.
In the
Input Data
area, edit the following fields as desired:
•
Input Length Unit
—Select mils or millimeters.
•
Dielectric Height (H1)
—Refer to the figure below.
•
Dielectric Height (H)
—Refer to the figure below.
•
Trace Thickness (T)
—Refer to the figure below.
•
Trace Width (W)
—Refer to the figure below.
•
Relative Permittivity (epsilon r)
—Refer to the figure below.
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 Transmission Line Calculator
.