Fresh PCB Concepts: PCB Design Essentials for Electric Vehicle Charging
Elementary, Mr. Watson: Rules of Thumb—Guidelines vs. Principles for PCB Design
Beyond Design: High-speed Rules of Thumb
Make the Right Decisions at the Right Time in the PCB Design Process
April 14, 2015 | Martin Cotton, Ventec International Corp.Estimated reading time: 1 minute
The right decisions are not always the easiest decisions, but making them well and as early as possible often avoids errors and addition costs. This is certainly the case in PCB design and a key decision influencing the design process and the eventual outcome is the selection of material and of the materials vendor. This is even more important when the PCB requires significant performance parameters to be met, such as high speeds.
What I am not trying to do is teach hardware or PCB design. What I am seeking to do is to consider the processes that lead to successful design and the errors that lead to risk, potential problems and compromises.
Let’s take an example of a backplane design that has been specified at 10Gbs with 100ohm impedance with a design target of 36 layers.
First, we need to ensure that we fully understand what the specification means. Are we sure we mean 10Gbs, which is a data rate in gigabits per second, and not 10Ghz, which is a frequency? Are we seeking that data rate for a single channel, or do we need that rate for a buss? The buss speed is the total of all the channels in that buss.
The next task would be to consider the design rules we’d like to apply based on the need for 100 ohms of differential impedance using two tracks that are in harmony so that losses are minimized. The geometry of those tracks and their positioning with the PCB structure are critical to realizing a good design that can be manufactured with a good yield.
The design is only good when the specifications are met and the PCB can be manufactured with a good yield.
This article originally appeared in the March 2015 issue of The PCB Design Magazine. To read the rest of this article, click here.
Share on:
Suggested Items
Fresh PCB Concepts: PCB Design Essentials for Electric Vehicle Charging
11/27/2024 | Team NCAB -- Column: Fresh PCB ConceptsElectric vehicles (EVs), powered by electricity rather than fossil fuels, are transforming transportation and reducing environmental impacts. But what good is an EV if it can't be easily charged? In this month's column, Ramon Roche dives into the role of printed circuit boards (PCBs) in electric vehicle charging (EVC)—and the design considerations.
From Construction Work to PCB Design in Under a Year
11/27/2024 | Andy Shaughnessy, Design007 MagazineAt the Anaheim Electronics & Manufacturing Show in October, I had the opportunity to talk with some new PCB designers, including Jon Smith of Frontgrade Aethercomm. During the Anaheim show, John Watson, a PCB design instructor at Palomar College, led a panel of his past and present students, including Jon, who shared his story of switching from a construction career to PCB design in a matter of months, courtesy of Watson’s Palomar College design curriculum.
PCB Layout Rules of Thumb for Consideration
11/25/2024 | Patrick Davis, Cadence Design SystemsJust because a “rule of thumb” is usually based on experience instead of precise facts doesn’t negate its value. For instance, when I told my kids that a good rule of thumb was not to back-talk to their mother, they discovered very quickly how accurate my advice was once they crossed that line. There are a lot of rules of thumb that we rely on daily, including those that apply to PCB design.
HPC Customer Engages Sondrel for High End Chip Design
11/25/2024 | SondrelSondrel, a leading provider of ultra-complex custom chips, has announced that it has started front end, RTL design and verification work on a high-performance computing (HPC) chip project for a major new customer.
Rules of Thumb for PCB Layout
11/21/2024 | Andy Shaughnessy, I-Connect007The dictionary defines a “rule of thumb” as “a broadly accurate guide or principle, based on experience or practice rather than theory.” Rules of thumb are often the foundation of a PCB designer’s thought process when tackling a layout. Ultimately, a product spec or design guideline will provide the detailed design guidance, but rules of thumb can help to provide the general guidance that will help to streamline the layout process and avoid design or manufacturing issues.