Q: How to design a proper ground plane and manage return paths in PCB layout?
Answer
A solid ground plane is the single most important factor for PCB signal integrity. Keep the ground plane continuous under all signal traces. For multi-layer boards use one full layer as GND (preferably layer 2 directly under the signal layer). Avoid narrow ground slots – current return paths will follow the signal trace but detoured by slots increasing loop inductance. Ground vias should be placed within 2 mm of every signal via carrying high-speed current. Use stitching vias along the board perimeter and around noisy sections. For mixed analog/digital split ground planes only at IC level connect at a single point (star ground) near the power source.
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