What should we pay attention to in anti-electromagnetic interference design?

In order to minimize the interaction and interference of the components on the printed circuit board, the high-frequency circuit and low-frequency circuit, high-potential and low-potential components can not be too close to each other. The input and output components should be as far away as possible, shorten the connection between the components as much as possible, and try to reduce their distribution parameters and the electromagnetic interference between them.

With the development of high-density fine linewidth / spacing, the distance between conductors and wires becomes smaller and smaller. The coupling and interference between conductors and wires will produce stray signals or error signals, commonly known as crosstalk or noise. The coupling can be divided into capacitive coupling and inductive coupling. The stray signals from these coupling actions should be reduced or eliminated by design or isolation.

Signal lines and ground lines are interlaced or surrounded by ground lines in order to achieve good isolation.

(2) when adopting the double signal band line, the adjacent two layer signal lines should not be arranged in parallel, but should be perpendicular and oblique to each other in order to reduce the generation of distributed capacitance and prevent the signal coupling. At the same time not into a right angle or sharp angle line, should take a circular arc or diagonal, as far as possible to reduce the interference that may occur.

Reduce the length of the signal line. At present, the most effective way to shorten the signal transmission line is to adopt multilayer structure under the condition of keeping high density line.

The highest frequency signal or the most high-speed digital signal assembly should be kept as close as possible to the input / output of the PCB connection edge.

This article is from ALLICDATA ELECTRONICS LIMITED.