High-speed PCB design is, to put it simply, any design where the physical properties of your circuit board, such as your layout, packing, layer stack up, interconnections, etc., begin to affect the integrity of your signals. The term “high-speed PCBs” lacks a universal definition. When digital electronics first emerged in the 1960s, the signal speed was slow, making PCB design relatively simple. Later, when the speed of the digital circuit signal increases, engineers discover that using conventional PCB design techniques for these high-speed printed circuits is ineffective. As a result, they optimize the circuit design and employ certain PCB base materials. The main goal of high-speed PCB layout is to provide circuit boards that are less prone to issues with signal integrity, power integrity, & EMI/EMC.
Our staff has already worked on high-speed PCB projects, thus we have this experience. Therefore, we made the decision to create this post in order to highlight the importance of its subject and to share our own experience. We think that our high-speed standardization, which is backed by real-world advice, would be beneficial to designers who are just starting to delve into this field.
A high-speed PCB can be recognized by a few traits. The design is hence fast if:
- The circuit is made up of several sub-circuits that are linked to one another by high-speed interfaces.
- “The signal rise time is at least 1/3 of the signal propagation time over the track;”
- The frequency of the digital signal is 50MHz and higher;
The printed circuit board is relatively small, which makes it difficult to locate the components (especially when you came across a high-speed interface layout).
Floor planning a High-Speed PCB
Where elements should be positioned in a high-speed PCB structure is not governed by any rules or standards in particular. As the largest central processing unit, IC normally needs to communicate with every other component on the board in some way, it is generally a good idea to locate it close to the center of the board. To keep routing between components short and direct, smaller ICs that are directly connected to the primary CPU can be positioned all around the major IC. After that, peripherals can be added all over the board to offer the necessary functionality.