{"id":17943,"date":"2022-12-07T08:13:35","date_gmt":"2022-12-07T16:13:35","guid":{"rendered":"http:\/\/www.autodesk.com\/products\/eagle\/blog\/?p=1556"},"modified":"2023-06-12T10:29:39","modified_gmt":"2023-06-12T17:29:39","slug":"top-10-tips-high-speed-pcb-design","status":"publish","type":"post","link":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/top-10-tips-high-speed-pcb-design\/","title":{"rendered":"Top 10 Tips for High-Speed PCB Design (2022 Update)"},"content":{"rendered":"\n

Learn how to make your first high-speed PCB design a success by minimizing crosstalk, EMI, and more.<\/em><\/p>\n\n\n\n

\"high-speed-pcb-design-iterate\"<\/figure>\n\n\n\n

It wasn\u2019t that long ago when the word \u201chigh speed\u201d didn\u2019t exist in the vocabulary of PCB designers. But these days, it seems to be just the opposite. Back then, the concern was all about putting the puzzle pieces together and strategizing your way through a physical board layout. But with high-speed PCB design<\/a>? Now there are a bunch of invisible forces to worry about<\/span>. Things like electromagnetic interference (EMI), crosstalk, signal reflection, and the list goes on. Here are some practical tips to make your first high-speed design process a success. <\/span><\/p>\n\n\n

More data, more EMI<\/h2>\n\n\n

In 2005, 3 Gbps was considered the typical high-speed data rate, but today engineers<\/span> deal with 10 Gbps and even 25. <\/span>Not only are they dealing with that rate, but there is a constant push to get faster clock rates<\/span>. <\/span>Devices <\/span>are getting smaller than ever to meet growing consumer demand. If you\u2019re designing today, you most likely already incorporate some aspect of high-speed design<\/span>. There’s DDR, PCI Express, USB, SATA, etc.<\/span><\/p>\n\n\n\n

At the heart of high speed, PCB design is an issue of interference. The faster your data rates are, the more issues you have trying with to protect the integrity of your signals. Most of these problems stem from electromagnetic radiation. This radiation is relatively harmless in small amounts when it makes contact with a circuit. But when it starts to interfere with the operation of your electronic device as a whole, then radiation becomes interference.<\/span> And Electromagnetic Interference (EMI) becomes a whole new world of issues! If you\u2019ve ever heard or encountered issues related to noise, then you know exactly what we\u2019re talking about.<\/span><\/p>\n\n\n\n

\"\"
Any current is going to produce a magnetic field, and that\u2019s the start of electromagnetic radiation. (Image source<\/a>)<\/em><\/figcaption><\/figure>\n\n\n\n

So you might be wondering, how in the world do you ever know if you’re working on a high-speed PCB design project without discovering it through EMI issues? There are several schools of thought here, and we\u2019ll break down the top 3:<\/span><\/p>\n\n\n\n

    \n
  1. Frequency<\/b>. The first thought is that high-speed design is categorized based on the frequency of a PCB and its ability to affect circuit performance. For some, this means anything above 50 MHz. Others categorize it into several buckets for low speed (<25 MHZ), moderate speed (25-100 MHz), high speed (100-1000 MHz), and anything above that is an ultra-high speed, reserved for RF designers. <\/span><\/li>\n\n\n\n
  2. Traces<\/b>. There\u2019s also the school of thought that you can use the physical dimensions of your trace to determine if you\u2019re working with a high-speed device. This guideline states that once a trace is more than \u2153 the rise time of your device\u2019s switching speed, then you\u2019ve got high speed. <\/span><\/li>\n\n\n\n
  3. Separation<\/b>. The last perspective takes a general approach, looking at your circuit design as a whole and asking the following question – does your system physically work together uniformly? Or do you have a bunch of subcircuits that are all organized into one larger circuit, with everything working together separately? The latter puts you into the realm of high-speed design. <\/span><\/li>\n<\/ol>\n\n\n\n

    Got your upcoming project classified as high speed? Great. That\u2019s all the background noise you need to worry about. Let\u2019s dive into our top 10 tips<\/a> for a successful design process.<\/span><\/p>\n\n\n

    1. Always start your high-speed PCB design process with a plan<\/h2>\n\n\n

    We\u2019re starting with the most obvious tip, but for a good reason. Without a plan and a strategy for your high-speed PCB design<\/a> project, you’ll likely encounter setbacks, respins, and unexpected issues. So before ever laying down a symbol or connecting a net, you need a checklist in hand for what lies ahead. Here are <\/span>a few questions to ask yourself:<\/span><\/p>\n\n\n\n