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Missouri University of Science
and Technology
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PCB Trace Impedance Calculator

Calculates the characteristic impedance and per-unit-length parameters
of typical printed circuit board trace geometries.

Select a configuration:

microstrip

Microstrip Trace

Embedded Microstrip Trace

Embedded Microstrip Trace

Stripline Trace

Stripline Trace

Dual Stripline Trace

Dual Stripline Trace

 

 

 

 

 

 

 

 Geometric Parameter Definitions:


W:   trace width
T: trace thickness
H (/H1) height of trace or dielectric above return plane
C: distance between the differential stripline pair
εr: relative permittivity of the dielectric

Electrical Parameter Definitions:


Zo:   characteristic impedance
Zc: effective characteristic impedance including the capacitance of distributed loads
Tpd: propagation delay
Lo: inductance per unit length
Co: capacitance per unit length

 

 

Acknowledgements:

The source for formulas used in this calculator (except where otherwise noted) is the Design Guide for Electronic Packaging Utilizing High-Speed Techniques (4th Working Draft, IPC-2251, February 2001.

THESE FORMULAS ARE APPROXIMATIONS! They should not be used when a high degree of accuracy is required.

This transmission line calculator was based on a concept developed by Douglas Brooks of UltraCAD Design, Inc.