EMI Bites: Uniform Instantaneous Impedance for Reflection-Free PCBs
EMI Bites: Uniform Instantaneous Impedance for Reflection-Free PCBs
A common PCB design flaw is varying trace widths or layout geometry, which alters the instantaneous impedance of a signal’s propagation path.
In a 50-ohm trace, any deviation from this characteristic impedance—due to inconsistent trace dimensions or layer changes—causes potential signal reflections.
These reflections can impair signal integrity, produce common mode currents, and escalate EMI, jeopardizing EMC compliance.
The solution?
Maintain uniform instantaneous impedance across the signal path by precisely controlling trace geometry and layer stackup.
This ensures a consistent characteristic impedance, eliminates reflections, and enhances EMC performance.
-Dario
P.S. Want more EMI control strategies to pass EMC?