Grounding and Ground Planes

A solid ground plane gives return currents a low-impedance path and is the single best layout practice.

Intermediate

Every signal current returns to its source. At high frequencies the return current flows in the ground plane directly underneath the trace, so:

use an unbroken ground plane (a full layer on 4-layer boards);
never route a fast signal over a split or gap in the plane;
keep high-current return paths (motors, switching regulators) away from sensitive analog circuitry;
connect decoupling capacitors to ground with short vias.

Splitting analog and digital ground is rarely needed; partitioning component placement over one solid plane usually works better.

Spotted a mistake or want to add detail? Suggest an improvement — Content Contributors' edits are reviewed by editors before they go live.

Discussion (0)