News & Updates

When you need to pass EMC certification and your new product is being crippled by a mysterious source of EMI, you’ll probably start considering a complete product redesign. Your stackup, trace geometry, and component arrangement are good places to start, but there might be more you can do to suppress specific sources of EMI. There are many different types of EMI filters that you can easily place in your design, and that will help suppress EMI in a variety of frequency ranges.

Previously, I described the PCB fabrication operations relative to inner layer processing, lamination, drilling, and plating. The last step in the process is outer layer processing which is described below. Once the desired plated copper thickness of a PCB has been achieved, it’s necessary to etch away the copper between the features in order to define the outer layer pattern.

There are many factors at play in determining the impact of inductance on high-frequency power distribution systems. Two topic areas, inductance of the decoupling capacitor and inductance of the power planes, were addressed in earlier articles. This article will focus on the inductance of the capacitor footprint and via inductance from the capacitor footprint back to the PCB power planes.

High-speed buses, whether single-ended or differential, can experience any number of signal integrity problems. A primary problem created by propagating signals is crosstalk, where a signal superimposes itself on a nearby trace. The industry-standard PCB design tools in Altium Designer® already include a post-layout simulator for examining crosstalk. Still, you can speed up crosstalk analysis in parallel buses when you use a powerful field solver.

Any time-dependent physical system with feedback and gain has conditions under which the system will reach stable behavior. Amplifier stability extends these concepts to amplifiers, where the system output can grow to an undesired saturated state due to unintended feedback. If you use the right design and simulation tools, you can easily account for potential instability in your circuit models before you create your layout.

The concept of design variants entails taking a single PCB design, and then on the assembly side, modifying specific components used in the design. Either by not installing, not installing, or choosing alternate components as replacements on a specific assembly to ultimately create different end products. In that way, you could support multiple product lines. This article describes the approach to working with variants. 

Before anything else, some advice. The revisions and lifecycle are an area that takes some planning. It used to be that Concord Pro was primarily for components, but now it has gone far beyond that. With the ability to store and manage many other items, including your various templates, projects, even PDF documents, not everything will have the same revision scheme. Concord Pro is so powerful that it can handle any revision scheme you’d want to set up.

Whether the board will be placed in a high pressure vessel or underwater, your design will need to withstand pressure to avoid failure. On the enclosure side, your vessel should be rated up to a certain pressure and may require frequent cycling to prevent implosion. On the electronics side, component selection and layout (especially at high voltage) become critical to preventing failure and ensuring reliability.

The first update of Altium Designer 20.2 and Altium NEXUS Client 3.2 is now available. You can update through the Altium Designer update system ("Extensions and Updates") or download fresh builds from the Downloads section of the Altium website. Click on "Read More" to see a list of all changes in this update.

The history of engineering, both electrical and mechanical, is littered with approximations that have fallen by the wayside. These approximations worked well for a time and helped advance technology significantly over the decades. However, any model has limits on its applicability, and the typical RLCG transmission line model and frequency-independent impedance equations are no different. Copper foil roughness modeling and related transmission line impedance simulations are just one of many areas in which standard models cannot correctly treat signal behavior.

Once you’re planning for production of any new board, you’ll likely be planning a battery of tests for your new product. These tests often focus on functionality and, for high speed/high frequency boards, signal/power integrity. However, you may intend for your product to operate for an extreme period of time, and you’ll need some data to reliably place a lower limit on your product’s lifetime. In addition to in-circuit tests, functional tests, and possibly mechanical tests, the components and boards themselves can benefit from burn-in testing.

If you remember your days in school, then you probably remember the feeling of happiness and celebration when you pass a big exam. You’ll feel the same sense of adulation when your board spin passes a barrage of pre and post assembly tests, but a complex design might not reach that stage unless you implement the right design for testability methods. There are some simple steps that can help your manufacturer identify and quickly implement important bare-board and in-circuit testing (ICT), especially on critical circuit blocks.

This article describes the best hints and tips for designers of rigid-flex circuits. These tips include choosing the most appropriate material, suggestions for coordinating the PCB with the manufacturer, and a set of rules to be followed while PCB design. 

There are a number of factors at play when it comes to the impact of inductance on high-frequency power distribution systems. This article will focus on the inductance of the capacitor footprint along with the inductance of vias from the capacitor footprint to the PCB power planes. Included are the various types and sizes of footprints for ceramic capacitors as well as a footprint for a tantalum capacitor; how changing the footprint impacts inductance and test results obtained for different capacitors.

In order to properly suppress common-mode noise, differential pairs must be routed in parallel, with perfect symmetry, and with matched lengths. In real PCBs, meeting these three objectives isn’t always possible. Instead of eyeing out your different pair lengths, the interactive routing tools in Altium Designer make differential pair length matching easy. You can encode permissible length mismatches as design rules as part of controlled impedance routing, or you can manually perform differential pair tuning using a variety of meandering styles. Here’s how this works in Altium Designer.