PCB Design Resources and Information | Altium

Explore content from blog posts to technical white papers gathered together for your convenience. All written by Altium's community of PCB design experts.

Lies Your Fabricator May Have Told You In some of our previous articles, we have talked about the various things that go wrong when a board design is turned over to the fabricator for manufacturing. Sometimes, the things that can go awry are due to design errors but the bulk of them can be ascribed to errors incurred during the fabrication process. This article will describe the errors that can be encountered and what, if anything, can be done to avoid them. We have previously Read Article

Using Prepreg vs. Core for Controlled Impedance Routing Are you designing for controlled impedance on the right layer material? When I was first learning the finer points of PCB design, my first impression that the core was some type of special material that did not have close resemblance to the other layers. This is not necessarily the case, but designers need to work within the core/prepreg stackup constraints imposed by the PCB manufacturing process. Although you may be constrained as to how the Read Article

Methods For Calculating And Measuring Impedance, Part 2 In Part 1 of this article, I reviewed the four basic types of PCB transmission lines and the various equations used for calculating the impedance associated with those lines. Part 1 also discussed why those equations only tell part of the story, and why there are other influencers including 2D field solvers; knowing the glass-to-resin ratio and knowing the frequency at which transmission lines will be used that impact the process of ensuring that Read Article

Methods For Calculating And Measuring Impedance, Part 1 In a previous article, I talked about the various transmission line properties that affect impedance. In this two-part article, I will address the methods used for calculating impedance. Included at the end of Part 1 is a list of 2D field solvers along with brief descriptions of their capabilities. Part 2 of this article will address other design aspects that influence impedance, including the frequency at which impedance should be measured Read Article

Transmission Line Properties That Affect Impedance—Hidden Features Here and in several other articles published on the Altium Resource section of the company’s website, the topic of transmission line impedance has been addressed from a number of different perspectives. I have addressed transmission line impedance previously in my article, The Evolution Of Simulation Technology and Impedance and, it might seem that we may have exhausted the field of potential information that can be provided on impedance, however Read Article

The Right Termination, Of The Right Size, At The Right Place In recent articles, I have addressed reflections, what they do to signals on transmission lines and how to control them through the use of terminations, serial and parallel. One area of confusion that continues to come up in our on-site classes regards the actual placement of terminators. This article will address this topic and hopefully provide some useful guidelines. Note: I am only addressing series and parallel terminations. Most of the Read Article

How the Fiber Weave Effect Influences High Frequency Signal Integrity The fiber weave effect can wreak havoc in networking equipment for copper and fiber When you look at any material under the microscope, it can feel like looking into another world. I spent many long hours on SEMs and TEMs comparing different materials and examining changes in optical and optoelectronic devices during operation. With new devices running at ever higher data rates, designs on rigid substrates need to accommodate one inconvenient Read Article

The Case Against Orthogonal Trace Routing in Multilayer PCBs Can you spot the orthogonal trace routing in this complex board? Neither can I... I occasionally see questions on forums, some blog posts, and even application notes that continue to recommend the use of orthogonal routing, usually in 2-6 layer boards. When looking at application notes, I tend to default to Rick Hartley’s advice and try to think about this advice in context. Unfortunately, recommendations in application notes are not always taken Read Article

Say "Hello" to the LogiSwitch Workbench The LogiSwitch Arduino Uno Workbench Proto-Extender Kit (Image source: LogiSwitch.net) As the Indian novelist Savi Sharma once said, "Everyone has a story." While this is undoubtably true (my mother certainly has lots of them), it's also true that some peoples' stories have more richness and complexity than others. Take my chum, Mike Pelkey, for example. If you perform a Google Search on "BASE Jumping" -- that is, parachuting from a fixed Read Article

Steaming Hot Steampunk Bruce Rosenbaum astride the Hendrick's Gin Grand Garnisher (Image source: ModVic.com) There is an ever-increasing interest in steampunk these days, and a lot of people dabble in various flavors of this genre, but it's rare that you run across someone who makes a living creating steampunk artifacts. Before we proceed, perhaps we should take a step back and remind ourselves that steampunk started out as a subgenre of science fiction or science Read Article

Reflecting on Your Design— What are Reflections and What Do They Do to a Signal? Part One In describing what happens when an electromagnetic field or wave is traveling on a transmission line, we often talk about the various things that can disrupt that wave. Among the most common of these things are reflections. Part 1 of this article will describe what reflections are and how they are caused. The second part will discuss what they do to a signal. Then, a separate article will address how reflections are controlled by terminations Read Article

Concord Pro and ECAD to MCAD Integration Introduction Back in September, I did a blog called PCB Design is a Team Sport, in which I specifically examined the different roles involved in the PCB Design Process. One of my conclusions was that the most important role involved in the whole design process is the Librarian. Everything begins and ends with the Library of Components, and if it is not correct, then Game Over. If the Librarian held the most important role, next would be the role Read Article

Stubs On Transmission Lines—What Do They Do And How Do You Keep Them From Happening? In other articles we have written PCB Design For Test Structures And Tests Performed, Part 2, and How to Control Switching Signals with Terminations for Best Signal Quality, we have described how to properly account for all the various factors that impact the design of high-speed signals. Within those topics, we’ve noted that stubs along a net may have an adverse effect on the quality of those signals. But, we have not thoroughly addressed stubs Read Article

The Evolution Of Automotive Electronics The number, functionality, and complexity of today’s automotive electronics has grown beyond leaps and bounds over the past several years. Certainly, the flagship of this technology is the Tesla automobile. But, even for those of us who can’t afford a Tesla, there is an increasingly widespread utilization of this technology in mid-range and even lower-end new cars. This article will describe the design environment represented by this technology Read Article

The Fundamentals of High Speed SerDes Design High speed SerDes design goes far beyond computer peripherals The challenges in high speed SerDes design filter right down to the PCB level and are all about backplane/daughtercard design, transmission line layout, selecting proper equalization schemes, and much more. This even gets down to the fundamentals, where stackup and power integrity become critical when driving transmitters and receiver ICs. If you’re designing a PCB as part of a SerDes Read Article

Some Pre-layout Power Spectrum Analysis Tips in Altium Designer Take advantage of your simulation tools before test and measurement. Here I want to expand a bit on the power spectrum analysis features in Altium Designer®. In a previous post, we looked at working with simulations involving a frequency modulated signal fed into a nonlinear component (an NPN transistor). In this simulation, we ended with the Fourier spectrum at the load resistor for various values of base voltage/current. In the time-domain Read Article

DDR5 PCB Design and Signal Integrity: What Designers Need to Know Development of the world’s first DDR5 RAM was announced just 1 year ago, with peak speed of 5200 MT/sec/pin (compare that to 3200 MT/sec/pin with DDR4) at 1.1 V. Full-scale production is set to begin in 2020, and demand for this new generation of memories with 8, 16, and 32 GB capacities will quickly outpace that for earlier generations. JEDEC rates DDR5 speeds up to 6400 MT/sec/pin, with bandwidth increased up to 300 GB/s. The faster speeds Read Article