Power Integrity

Browse our library of resources to learn more about pcb design and power integrity.

Getting Started With PDN Analyzer PDN Analyzer for DC Power Integrity PDN Design for the PCB Designer

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

Debugging Power Supply Noise to Reduce Signal and Clock Jitter 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

Phase noise measurement with spectrum analyzers

How to Take a Phase Noise Measurement for High Speed Signals There are plenty of noise sources in your PCB, and phase noise can be one of those sources that is difficult to pin down in a real board. If you’re debugging a high speed board with high BER, then you’ll likely need to gather a phase noise measurement from the failing board section, or from your clock. Without getting too deep into the IC side of a system, phase noise may be an inherent property of the component you are using, such as the PLLs Read Article

Everything You Need to Know About Ferrite Beads

Everything You Need to Know About Ferrite Beads As noted in my previous blog regarding PDS design, the whole power supply conundrum is one that has been plagued over the years with a number of erroneous rules-of-thumb; “black magic” design rules and confusion as to what does or doesn’t work. One of the most controversial topic areas focuses on the use of ferrite beads as a means of controlling and containing EMI. There is conflicting information concerning the use of ferrite beads and it is Read Article

How Do Pads and Vias Impact Total Capacitor Parasitic Inductance?

How Do Pads and Vias Impact Total Capacitor Parasitic Inductance? In this blog article we discuss how the footprint and mounting style affect capacitor parasitic inductance. The pads and vias back to the PCB power planes increase the total series inductance of the capacitor. Read Article

Decoupling Capacitor and Bypass Placement Guidelines

Decoupling Capacitor and Bypass Placement Guidelines Power integrity problems are normally viewed from the perspective of the power supply, but looking at the output from ICs is just as important. Decoupling and bypass capacitors are intended to compensate power fluctuations seen on the PDN, which ensures your signal levels are consistent and a constant voltage is seen at the power/ground pins on an IC. We’ve compiled some important bypass and decoupling capacitor design guidelines to help you use Read Article

With so many possible noise sources, it can be difficult to tell them apart.

Is it Simultaneous Switching Noise or Crosstalk? How can you distinguish simultaneous switching noise and crosstalk? Take a look at the difference between these two signal integrity problems in this article. Read Article

Analog Signal Bandwidth and its Relation to Power Integrity

Analog Signal Bandwidth and its Relation to Power Integrity Here’s how your analog signal bandwidth interacts with your PDN, and how it affects power integrity. Read Article

PCB Debugging: Tips, Tools, and Tricks

PCB Debugging: Tips, Tools, and Tricks There are some basic testing and PCB debugging steps you should take when your new prototype has some functionality and signal integrity problems. Read Article

Using an IPC-2221 Calculator for High Voltage Design

Using an IPC-2221 PCB Clearance Calculator for High Voltage Design Unsure of your conductor spacing requirements in high voltage PCBs? An IPC-2221 calculator can help. PCB design and assembly standards aren’t there to constrain your productivity. Instead, they’re there to help create uniform expectations of product designs and performance across multiple industries. With standardization comes the tools for compliance, such as calculators for certain design aspects, processes for auditing and inspection, and much Read Article

Living on the Edge (Rate) Rise and fall frequency

Living on the Edge (Rate) — It’s All About Time and Distance The focus of this article is the clarify the origins of the phrase edge rate, what it really means relative to the design process and the best means for addressing it. Read Article

Optimizing Power Consumption

Optimizing Power Consumption Power efficiency—energy efficiency if you’re a purist—has become perhaps the highest-profile aspect of system design. This is especially true for IoT applications where a device may need to operate for years on harvested energy or a cell battery. Thus, a critical stage of design is power optimization. Typically, the first stage of power optimization is setting the power budget. For example, the system spec might state that the device has to be Read Article

EMI from Heatsinks and What You Can Do About It

EMI from Heatsinks and What You Can Do About It Selecting the right heatsink can help you keep your system cool and prevent EMI. While it may not be obvious, or while most designers may not think to check, heatsinks can generate EMI when they are connected to a switching element. This is a common problem in power supply design, and whenever a heatsink is placed in contact with a component that switches with high current draw at high frequency. Reducing EMI from heatsinks requires balancing the Read Article

Some Techniques for Suppressing DC-DC Converter EMI in IoT Products

Some Techniques for Suppressing DC-DC Converter EMI in IoT Products This Li ion battery is most likely connected to a switching regulator to provide stable power. Suppressing EMI susceptibility in IoT devices from various sources is critical to ensuring your new product will work as designed. Similarly, your IoT product should limit spurious emissions if you want it to comply with EMC regulations. Among the various sources of radiated EMI from your next product, EMI within the device itself should also be Read Article

SMPS Circuit Design: Which Switching Frequency to Use?

SMPS Circuit Design: Which Switching Frequency to Use? Power supply on a network switch Power electronics and switched-mode power supply (SMPS) designers should know that working with higher switching frequencies can lead to higher switching losses in your system. However, the push to miniaturize power supplies, and the components that go into them, compels designers to work with higher switching frequencies in their SMPS circuit designs. This then creates problems where switching losses and noise Read Article

Radiated EMI Sources in High Speed/High Frequency PCBs

Radiated EMI Sources in High Speed/High Frequency PCBs Radiated EMI measurements during EMC testing The image above shows a snapshot of results from an EMC test under CISPR requirements (U.S. uses FCC certification requirements). This product is right at the edge of Class B limits on radiated emissions. We can see a very complicated resonance spectrum in this plot with a large number of sharp peaks superimposed on wide peaks at lower level. What causes all of this radiated noise? There a number of Read Article

PDN Impedance Analysis and Modeling: From Schematic to Layout

PDN Impedance Analysis and Modeling: From Schematic to Layout Do you know the factors that determine the impedance of your PDN? Here’s what you need to know about PDN impedance analysis and modeling. Read Article