design countermeasures in the design process
date:2018-11-07 11:12:00
Consider EMI design countermeasures in the design process
In general, electronic products usually complete the preliminary verification design, that is, synchronous electromagnetic interference verification work. At this time, the design scheme still has a considerable degree of design modification flexibility in appearance and mechanism. If the electromagnetic interference problem detected by the design is verified. Quite serious, you must choose to reconfigure components or improve the settings of some mechanisms or protective materials.
However, if the influence of the electromagnetic interference problem is limited by the improvement of the component reconfiguration, or the PCB board itself is too small, there is no room to reconfigure the key components. At this time, the design policy for improving the electromagnetic interference problem must be directed to different design techniques. Or use the electromagnetic wave suppression countermeasure component to perform key design improvement. Most of the design schemes are not easy to correct the problems in the later verification, which may cause electromagnetic interference problems, or reduce the additional cost of inputting and correcting the electromagnetic interference problem. It is more appropriate to add circuit design considerations for reducing electromagnetic interference in each development stage. Allows the overall circuit design to reduce electromagnetic interference problems.
For example, in the current most popular smart mobile devices, most of the general design conditions are selected to be included in the core processor (CPU), graphics processing unit (GPU), memory (DDR SDRAM), storage memory card... The key components, while the high-frequency components are mainly processors, graphics processors, and memory. At present, the external clock of the mobile device processor exceeds 1 GHz, which is not easy to improve in a small-sized design with relatively limited mechanism space. Its electromagnetic interference problem, and high-frequency operation is also easy to interfere with the normal operation of peripheral components. The more common practice is to make the block grounding of the PCB printed circuit board, and use the metal shield to shield the high-frequency components with metal to minimize the electromagnetic Interference effects.
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