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Simulation / Analysis for PCB Design

Return loss vs. reflection coefficient

S11 Parameter vs. Return Loss vs. Reflection Coefficient: When Are They the Same? What is the difference between return loss vs. reflection coefficient and the S11 parameter? We’ve got your answers in this article. Read Article

Integrated circuit CMOS load capacitance

How Load Capacitance on a Transmission Line Affects Your Signals If you ever read about transmission lines and integrated circuit datasheets, there is this seemingly mysterious quantity called load capacitance. This value depends on the geometry of the component lead connected to the transmission line, as well as the substrate material and distance to the reference plane on the integrated circuit die. When working with transmission lines, the load capacitance of a component has some important effects on signal Read Article

Microwave Cavity Resonator Emissions in Your PCB Layout

Microwave Cavity Resonator Emissions in Your PCB Layout Even digital designers need to worry about cavity resonant emission in PCBs. Here’s how your circuit board can act like a microwave cavity resonator. Read Article

EMI filter simulation for power supplies

EMI Filter for Simulating Noise Suppression with Altium Designer 20 and Altium 365 Simulations can get very complicated, but Altium 365 helps you keep your simulation models and data organized. Read Article

transmission line transfer function ABCD parameters S parameters

Transmission Line Transfer Function from ABCD and S-parameters High frequency and data rate channels can be routed as a mode-selective transmission line. Here’s when you should consider this routing technique. Read Article

What is impulse response function Fourier transform

What are Impulse Response Functions? You can get a transfer function from a simulation, but what is an impulse response function? Learn more in this article. Read Article

Modeling PCB Interconnects as Causal Systems

Modeling PCB Interconnects as Causal Systems Real PCB interconnects are causal systems and must be modeled with the correct time-dependent behavior. Read Article

The Basics of Signal Integrity Analysis in Your PCB

The Basics of Signal Integrity Analysis and Simulation in PCB Design Read and learn the important steps in signal integrity analysis and how these steps reveal problems in your PCB layout. Read Article

buck converter simulation

Buck Converter Simulation in Altium Designer Are you designing a step-down switching power supply? It helps to perform a buck converter simulation during circuit design. Altium Designer makes it easy to perform a buck converter simulation directly from your schematic. Read Article

Modeling Capacitor Impedance Vs. Frequency Using an Excel Spreadsheet

Modeling Capacitor Impedance Vs. Frequency Using an Excel Spreadsheet As noted in an earlier article, based on class notes from our two-day design course, getting the power subsystem design correct is the most challenging aspect of today’s high-speed PCB design process. A major aspect of this process is modeling the power supply to ensure that it will function properly in the end product. A critical part of this modeling effort focuses on being able to model capacitor impedance vs frequency. This is simple enough Read Article

EMI Case History — Noise Problems and Their Solutions — Part 2

EMI Case History — Noise Problems and Their Solutions — Part 2 In Part 1 of this article, I described an EMI noise problem occurring in a LCD touch screen display of an autonomous robot cleaning machine. In order to provide consulting services we needed to solve a problem which originated because of the ground and supply bounce in the leads of the IC devices that were incorporated into that display. In Part 1, I also described the type of equipment in which the operation problem arose, the origin of the Read Article

High Voltage SMPS PCB Layout to Minimize Heat and Noise

High Voltage SMPS PCB Layout to Minimize Heat and Noise Whether you are performing AC-DC conversion or DC-DC conversion, switching power supply layouts are common in high voltage design and must be constructed carefully. Although this system is quite common, it will easily radiate EMI due to the fast changes in voltage and current during switching. Designers can rarely adapt existing designs into new systems as a minor change in one area can create an EMI problem that is difficult to diagnose. With Read Article

How to Select an Inductor for a Buck Converter

How to Select an Inductor for a Buck Converter An SMPS is one of those quiet (yet electrically noisy) devices that makes your favorite electronics run smoothly. They sit in the background quietly doing their duty, yet your board wouldn’t operate without them. As part of DC-DC converter design for power-hungry applications, component selection is quite important for ensuring stable power delivery to a load with high efficiency. Among the numerous DC-DC converter topologies, a buck converter Read Article

Debugging Power Supply Noise to Reduce Signal and Clock Jitter

How to Reduce Clock and Signal Jitter: Debugging Power Supply Noise Low level components need ultra-stable power, and high speed digital signals need to have repeatable edge transition times. The two aspects of digital signalling are related, and you’ll need to suppress all aspects of power supply noise to reduce jitter in a digital system. During a design debug, you’ll need to gather measurements throughout your board if you want to isolate and eliminate sources of power supply noise. Here’s how you can isolate Read Article

Transmission Line Impedance Measurement

Transmission Line Impedance Measurement: Even vs. Odd Mode If you need an accurate transmission line impedance measurement, here are the important values you need to use in your next board. Read Article

Will these amplifiers be stable during operation? Here’s what you should know about amplifier stability in your PCB.

Amplifier Stability at High Frequencies and Stray Capacitance Amplifiers are one of those critical components that make modern life possible. From wireless communication to power electronics, amplifiers need to run stably and predictably for these products to work properly. Stability analysis is one of my favorite topics in physics and engineering, and it always tends to crop up in places you would least expect. One of these places is in amplifiers. Any time-dependent physical system with feedback and gain Read Article

Near-field vs. far-field radiation from a smartphone

Near-field and Far-field EMI: What's Causing Noise Problems in My PCB? If you’re an antenna designer, then you’re likely familiar with all aspects of near-field vs. far-field radiation. Given the litany of radiated EMI problems that cause noise within and outside of an electronic device, one might suddenly realize their new product is acting like a strong antenna. To understand how EMI affects your circuits, it helps to understand exactly how near-field vs. far-field radiation from your PCB affects your ability to Read Article