Chapter 6
PCB Calculators
6-8
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You can use the
PCB Differential Impedance Calculator
to calculate the
following parameters for differential pairs:
•
Characteristic Impedance (Zo).
•
Per unit length Capacitance (Co).
•
Per unit length Inductance (Lo).
•
Propogation Delay (tpd).
•
Differential Impedance (Zdiff).
The
PCB Differential Impedance Calculator
supports:
•
•
Embedded Microstrip Calculations
.
•
Centered Stripline Calculations
•
Asymmetric Stripline Calculations
Microstrip Calculations
Complete the following steps to perform microstrip differential impedance
calculations:
1.
Select
Tools»PCB Differential Impedance Calculator
.
2.
Select
Microstrip
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 Thickness (H)
—Refer to the figure below.
•
Trace Thickness (T)
—Refer to the figure below.
•
Trace Width (W)
—Refer to the figure below.
•
Trace Spacing (S)
—Refer to the figure below.
•
Relative Permittivity (epsilon r)
—Refer to the figure below.
Or
If you wish to define the Characteristic Impedance (Zo) yourself, click
User Defined Zo
and edit the following fields as desired:
•
Input Length Unit
—Select mils or millimeters.
•
Dielectric Thickness (H)
—Refer to the figure below.
•
Trace Spacing (S)
—Refer to the figure below.
•
Characteristic Impedance (Zo)
—Refer to the figure below.
