Based On Computer Motherboard High-frequency PCB EMC Design And Application

With the rapid development of electronic information technology, high-speed PCB(Printed Circuit Board) has been applied in more and more electronic devices. However, sincethe PCB operates at a high frequency, transient pulse produces electromagnetic interference(EMI). Because electromagnetic environment is deteriorating, a large number of electronicdevices can not work properly in the high-complexity, high-intensity electromagneticenvironment. In the mean time, the electromagnetic radiation hurt people’s health. To solvethis problem, EMC standards have been developed and implemented according to the relevantlaws in worldwide, and the products which do not meet the relevant EMC standards will beforbidden to sell on the market. Therefore, the research on electromagnetic compatibility(EMC) has great significance on the development of China’s electronic industry and reductionof the electromagnetic pollution.The main work of this paper analyze the fail frequency for PS/2, USB, VGA, Audio andLAN interface based on the radiation test for computer systems and engineering experience.The optimize engineering solutions of electromagnetic interference are proposed, the use offiltering, decoupling, grounding methods to modify PS/2, USB, VGA, Audio and LAN andelectromagnetic radiation of a single I/O interface is verified to make the single interfacemeets standard requirements. This article relates to the specific EMC design technology ofEMC filtering components and PCB layout, which are the foundation of the circuit boarddesign for suppressing electromagnetic interference noise. The EMI design of high-speedcircuit in the computer’s motherboard is taken as an example with Intel set platform, themotherboard electromagnetic interference problems at the design stage are analyzed and thedesign rules, EMC design techniques are applied to solve the problem of electromagneticinterference reduction in PCB design. The EMC design technology includes stacked lamellarstructure design, high-speed signal line EMI wiring design, clock circuit EMI design and the I/O area suppress EMI design. The design in this paper shows that by introducing EMCproduct design method at the product design stage, the product development process and timeare reduced. In the mean time, the cost of test and EMC rectification are reduced, As a result,the cost of product development is saved, and the improved methods are also suitable for therelated electronic products for meeting the EMC standards.