3W principle and 20H principles and the explanation of the five-five principles

3W principle 3W is the distance between the line and the line remains 3 times width. You can say 3 hours. But here h refers to the line width. Not a medium thickness. To reduce line crosstalk, it should be ensured that the line spacing is large enough. When the center distance is not less than 3 times, the linear electric field can be kept interfere with each other, called 3W rules. If the electric field to reach 98% does not interfere with each other, 10W rules can be used. Generally, in the design process, it is 3W due to the pass lines that cannot be met, and we can use only 3W processing, such as clock signals, and reset signals. 20h principle It means the distance between the power layer relative to the formation of 20h, of course, is also to suppress the edge radiation effect. Electromagnetic interference is radiated outward on the edge of the board. The power layer is contracted so that the electric field is only conducted within the range of the ground layer. Effectively increases EMC. If the inner zone is 20h, 70% of the electric field can be limited to the ground edge; the contraced 100h can be limited to 98% electric field. 20h principle in PCB design? The use of "20h Rules" means that it is necessary to ensure that the edge of the power supply plane is more than 20 times that is equivalent to the two flat macades than the edge edge of the 0V plane. This rule is often required to be used as a side shot emission technology (inhibiting edge radiation effect) from the side shot of the 0V / power supply planar structure. However, 20h rules provide significant results only under certain specific conditions. These specific conditions include: 1. The rise / fall time of current fluctuations in the power bus is less than 1 ns. 2. The power supply plane is on the internal level of the PCB and is a 0V plane with the upper and lower levels adjacent to it. These two 0V plane extending outwardly to at least 20 times they are each and the power supply plane. 3. On any frequency care, the power bus structure does not generate resonance. 4. The total or more of the PCB is at least 8 or more. May five principles The number of printed plates is selected, that is, the clock frequency to 5 MHz or pulse rise time is less than 5ns, and the PCB board must adopt a multi-layer board. This is a general rule. Some time is considered for factors such as cost, using a double-laminate In this case, in this case, it is preferable to use the side of the printed board as a complete flat layer. , Read full text, original title: PCB LAYOUT: 3W principle, 20h principle, the explanation of the five five principles! Article Source: [Micro Signal: FCSDE-SH, WeChat Public Number: Semiconductor PDSA] Welcome to add attention! Please indicate the source of the article.

Our other product:

Professional lightning protection system for Tower	Professional FM Radio Station Equipment Package	FMUSER FU-1000C 1000W FM Transmitter With USB Audio Input Interface
FMUSER 200W FM Radio Broadcasting Package	Hotel IPTV Solution	FMUSER FSN-1000T V5.0 1KW FM Radio Broadcast Transmitter