The ground plane: Lord of the Board
- Software size：10M
- Support platform：Windows/Linux/Unlix
- Release time：2017-01-16 12:03:07
The way that a circuit is laid out on a PCB is critical to its EMC performance. At high frequency all tracks must be regarded as components in their own right, since the coupling of high frequency signals from one part of the circuit to another is mediated by their stray capacitance and inductance. Even if the equipment is a simple analogue circuit with no HF emissions sources, susceptibility to RF disturbances means that it must still be laid out with RF performance in mind. The schematic rarely if ever tells this side of the story; PC tracks appear as nothing more than lines on the diagram joining pins of lumped components such as ICs, resistors and capacitors.
But every track on a board exhibits its own partial self inductance, and mutual inductance and capacitance to other nearby areas of copper, and if these are uncontrolled then the performance of the board at high frequency – and that means the EMC performance of the circuit – is also uncontrolled. The simplest and most effective way of fixing the characteristics of all such tracks is to implement a ground plane on the board.
The content of this article includes:
2. How a ground plane works
3. Ground planes in the xy direction: breaks, moats and joins
4. Ground planes in the z direction: layer stack-up
5. Constant impedance tracks over the ground plane
About the Author:
Tim Williams is a consultant with Elmac Services and is the author of EMC for Product Designers
This paper focus on ground plane and you are welcomed to download this paper, hope it is of help to you.