EMI Bites: Eliminate Ground Bounce with a Robust Return Plane
EMI Bites: Eliminate Ground Bounce with a Robust Return Plane
Ground bounce, a transient voltage spike in the return path, degrades signal integrity and increases EMI, often due to impedance discontinuities in the return path.
When signals share a return path, such as a single ground trace, their fringe fields overlap, causing interference, especially across layers.
Signal layers or traces placed too close to each other tend to produce ground bounce, as one signal’s transition excites another when sharing the same return path.
Solution: Place a uniform Return Reference Plane (RRP) adjacent to each signal layer to maintain consistent characteristic impedance, containing fringe fields and preventing overlap.
Assign layers in pairs (SGN/GND or PWR/GND) in the stackup, ensuring a solid return and reference plane to balance cost and performance.
This reduces common mode emissions, eliminates ground bounce, and enhances EMC performance.
-Dario
P.S. Want more EMI control strategies to pass EMC?