News & Updates
In this article, we’ll discuss the key design features to implement, and steps to take prior to fabrication that will help prevent some common DFM problems. I’ll also provide examples of where I commonly see these PCB DFM problems in signal integrity circuits.
If you’re working with a high-speed digital component, there are some simple power integrity rules that should be followed. However, there is one quantity that is sometimes ignored when building a PDN impedance simulation: the spreading inductance of your plane pair. Here are some points designers should know about the spreading inductance of a plane pair.
In this article, I’ll present some design basics that every new designer should follow to help ensure their design process is successful. Some of these points may challenge the conventional view of how circuit boards are constructed, but they are intended to help balance low noise signaling, manufacturability, and ease of solving a layout.
The primary goal of your traces is to carry signals throughout your board without losses. To do this properly, you must familiarize yourself with the requirements for signals on the printed circuit board and how to optimize the topology of the board in terms of signal integrity. We will analyze the most popular routing cases applicable for using the Gloss and Retrace tools in Altium Designer to optimize your signal integrity.
High voltage PCBs are subject to certain safety and reliability concerns that you won’t find in most other boards. If your fabrication house specializes in high voltage PCBs and keeps materials in stock, they can likely recommend a material set, as well as a standard stackup you might use for certain voltage ranges and frequencies. If you need to choose your own materials, follow the tips below to help you narrow down to the right material set.
There are some guidelines I see many designers implement as a standard practice, often without thinking about it. Some of these practices are misunderstood or implemented without best practices. Others are implemented without thinking about the potential problems. One of these is the use of tented vias, which is sometimes implemented in a PCB layout by default. Is this always the right practice?
The idea of a purely capacitive load is something of a fallacy. Yes, capacitors exist, but all capacitors are non-ideal, and it is this deviation from a theoretical capacitance that determines how to impedance match a load that exhibits capacitive behavior. Let’s take a look at this important aspect of interconnect design and see what it really means to terminate a capacitive load.
There are all sorts of version control systems out there that people have been using with their PCB design software. As discussed in Why Use a Version Control System, we looked at different options ranging for local hard drive storage to sophisticated online revisioning systems. In this article we will be reviewing the differences between a standard VCS and Altium 365.
Version Control Systems (VCS) have been around for many decades within the software world but can be surprisingly new to some folks in the electronics design industry. This article will cover what a VCS is, what it does, and why you should be using one for your PCB design projects.
Designers often conflate leftover annular ring and pad sizes - they need to place a sufficiently large pad size on the surface layer to ensure that the annular ring that is leftover during fabrication will be large enough. As long as the annular ring is sufficiently large, the drill hit will not be considered defective and the board will have passed inspection. In this article, I'll discuss the limits on IPC-6012 Class 3 annular rings as these are a standard fabrication requirement for high-reliability rigid PCBs.
Sending a board out for fabrication is an exciting and nerve-wracking moment. Why not just give your fabricator your design files and let them figure it out? There are a few reasons for this, but it means the responsibility comes back to you as the designer to produce manufacturing files and documentation for your PCB. It’s actually quite simple if you have the right design tools. We’ll look at how you can do this inside your PCB layout and how this will help you quickly generate data for your manufacturer.
To pour or not to pour, to stitch or not to stitch… Over many years, some common “rules of thumb” have become very popular and, ultimately, taken a bit out of context. Rules of thumb are not always wrong, but taking PCB design recommendations out of context helps justify bad design practices, and it can even affect the producibility of your board. Like many aspects of a physical PCB layout, via stitching and copper pour can be like acid: quite useful if implemented properly, but also dangerous if used indiscriminately.
Power MOSFETs enable a huge range of electronic systems, specifically in situations where BJTs are not useful or efficient. MOSFETs can be used in high current systems in parallel arrangements, but what about their use in series? Both arrangements of MOSFETs have their pitfalls that designers should consider. Let’s look at MOSFETs in series as they are quite useful in certain systems, but be careful to design your circuits and your PCB for reliability.
I can’t think of a single product I’ve built that doesn’t require capacitors. We often talk a lot about effective series inductance (ESL) in capacitors and its effects on power integrity. What about effective series resistance (ESR)? Is there a technique you can use to determine the appropriate level of resistance, and can you use ESR to your advantage?
If your goal is to hit a target impedance, and you’re worried about how nearby pour might affect impedance, you can get closer than the limits set by the 3W rule. But what are the effects on losses? If the reason for this question isn’t obvious, or if you’re not up-to-date on the finer points of transmission line design, then keep reading to see how nearby ground pour can affect losses in impedance-controlled interconnects.
If you need to capture sound waves for your electrical device to process, you'll need a microphone. However, microphones these days have become very advanced, and there are so many options to choose from. They range from the relatively simple and popular condenser type microphones to state-of-the-art sound conversion solutions incorporating internal amplifiers and other electronic processing functionality. In this article, we'll take a look at some of the options available.
There are many times where you need an amplifier with high gain, low noise, high slew rate, and broad bandwidth simultaneously. However, not all of these design goals are possible with all off-the-shelf components. Here are some points to consider when working with a composite amplifier design and how to evaluate your design with the right set of circuit simulation tools.
Simple switching regulator circuits that operate in compact spaces, like on a small PCB, can usually be deployed in noisy environments without superimposing significant noise on the output power level. As long as you lay out the board properly, you’ll probably only need a simple filter circuit to remove EMI on the inputs and outputs. As the regulator becomes larger, both physically and electrically, noise problems can become much more apparent, namely radiated EMI and conducted EMI in the PCB layout.
A PCB design review is a practice to review the design of a board for possible errors and issues at various stages of product development. It can range from a formal checklist with official sign-offs to a more free-form inspection of schematic drawings and PCB layouts. For this article, we will not delve into what to check during a design review process but rather look at how a review process itself usually unfolds and how to optimize it to get the most out of your time.
As we established in Part 1, the PCB design review and collaboration practices have room for improvement in many organizations. To address this, we developed Altium 365. Let's examine how running a PCB project through Altium 365 compares to other methods.
If you look on the internet, you'll find some interesting grounding recommendations, and sometimes terminology gets thrown around and applied to a PCB without the proper context or understanding of real electrical behavior. DC recommendations get applied to AC, low current gets applied to high current, and vice versa... the list goes on. One of the more interesting grounding techniques you'll see as a recommendation, including on some popular engineering blogs within the industry, is the use of PCB star grounding.
Every PCB has silkscreen on the surface layer, and you’ll see a range of alphanumeric codes, numbers, markings, and logos on PCB silkscreen. What exactly does it all mean, and what specifically should you include in your silkscreen layer? All designs are different, but there are some common pieces of information that will appear in any silkscreen in order to aid assembly, testing, debug, and traceability
Designing high-speed channels on complex boards requires simulations, measurements on test boards, or both to ensure the design operates as you intend. Gibbs ringing is one of these effects that can occur when calculating a channel’s response using band-limited network parameters. Just as is the case in measurements, Gibbs ringing can occur in channel simulations due to the fact that network parameters are typically band-limited.
In electronics, there is the possibility that your PCB can get pretty hot due to power dissipation in certain components. There are many things to consider when dealing with heat in your board, and it starts with determining power dissipation in your design during schematic capture. If you happen to be operating within safe limits in a high power device, you might need an SMD heat sink on certain components. Ultimately, this could save your components, your product, and even the operator.
One thing is certain: power supply designs can get much more complex than simply routing DC power lines to your components. RF power supply designs require special care to ensure they will function without transferring excessive noise between portions of the system, something that is made more difficult due to the high power levels involved. In addition to careful layout, circuitry needs to be designed such that the system provides highly efficient power conversion and delivery to each subsection of the system.
Overvoltage, overcurrent, and heat are the three most likely events that can destroy our expensive silicon-based components or reduce our product’s life expectancy. The effects are often quite instant, but our product might survive several months of chronic overstress before giving up the ghost in some cases. Without adequate protection, our circuit can be vulnerable to damage, so what should we do? Or do we need to do anything?
Today’s PCB designers and layout engineers often need to put on their simulation hat to learn more about the products they build. When you need to perform simulations, you need models for components, and simulation models often need to be shared with other team members at the project level or component level. What’s the best way for Altium Designer users to share this data? Read this article to learn more about sharing your models with other design participants.