ISSUE: November 2021


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» Why EM Is Replacing SPICE For Simulation Of Board-Level Power Delivery

» Consider The Tradeoffs When Choosing Probes For 48-V Applications

» MOSFET Packaging Innovations For SWaP-Optimized Space Power Systems

» Focus On Magnetics:
Stored Energy In A Saturating Inductor Is Not Constant

» Book Review:
Compendium Untangles The Complexities Of PDNs

» Spotlight On Safety & Compliance:
One Month Left To Download EMC + SIPI 2021 Proceedings

» New Power Products

» New on

» Other Top Power News

From the Editor's Desk

David G. Morrison
Editor, HOW2POWER TODAY       

Building a smaller, more efficient, more controllable power supply such as a VRM or POL converter doesn’t satisfy all the requirements for powering modern high-speed digital circuits. There are severe challenges in managing board-level parasitics to deliver continuously well-regulated supply voltages to the highly dynamic loads. The VRM or POL becomes an integral component that must be in harmony with the power distribution network (PDN) to achieve the well-controlled impedances required. This is the field of power integrity (PI). Two articles in this issue discuss what those PDN design requirements mean relative to the voltage regulator. An article by Heidi Barnes and Steve Sandler explains why conventional approaches to power supply simulation using lumped SPICE are now inadequate, and why EM field solvers are needed to properly model voltage regulators to support their effective application in PDNs. Meanwhile, Dennis Feucht’s review of a recently re-issued classic text on PDN design methods gives an overview of the concepts and practical techniques that govern design of PDNs. This has been an area that power semiconductor and power module developers have tended to ignore, leaving it to the customers to work out the complexities of routing power. But as these two articles suggest, the worlds of power conversion and power integrity are colliding. At some point, power supply developers may have to take greater ownership of power delivery, just as they have with design of the voltage regulator. That may be accomplished by providing better voltage regulator models to their customers, or by consulting with customers through the PDN design process. It will be interesting to see how the PI requirements impact approaches to power supply design and development in the future.


Why EM Is Replacing SPICE For Simulation Of Board-Level Power Delivery

by Heidi Barnes, Keysight Technologies, Santa Rosa, Calif. And Steve Sandler, Picotest, Phoenix, Ariz.

In the power electronics world of voltage regulators there is such an entrenched history of SPICE models that few engineers look further than running a freeware LTspice simulation with vendor-supplied models to predict behavior. This “lumped-SPICE” type simulation assumes perfect conductors between the bill-of-material components in the schematic. However, signal integrity engineers designing power delivery to high-speed digital loads are finding out the hard way that lumped-SPICE simulations are leaving out critical time delays and parasitic behaviors that only an EM simulated model of the PCB interconnect can get right. Getting it wrong can result in incorrect prediction of power rail resonances and lead to voltage regulator designs that are on the edge of instability. Ultimately, it can lead to a complete failure of the high-speed circuitry. Read the article…

Simulation of regulator output
impedance using a full 3D EM model
with PCB interconnect parasitics shows
that the lumped-SPICE simulated phase
can be off by as much as 6 degrees at
frequencies as low as 100 kHz.

After identifying four probe classes,
where they are used, and some
example models, this discussion
focuses on their use in low- and
high-side gate drive measurements
of GaN devices.

Consider The Tradeoffs When Choosing Probes For 48-V Applications

by Ken Johnson and Yash Gupte, Teledyne LeCroy, Chestnut Ridge, NY

With growing power requirements necessitating voltage levels higher than 12 or 24 Vdc, markets for products powered by 48 Vdc are growing quickly. Simultaneously, GaN is displacing silicon in many applications because its faster rise times translate to better efficiency, smaller size and lighter weight. However, the faster rise times require about 1 GHz of oscilloscope and probe measurement bandwidth. A thorough understanding of the different types of probes available for use, and their tradeoffs, will allow you to make the best possible measurements of signals in your 48-V power-conversion systems. This article looks at active and passive probe types that are candidates for measuring switching waveforms in 48-V power converters, particularly those using GaN power transistors. Read the article…

MOSFET Packaging Innovations For SWaP-Optimized Space Power Systems

by Oscar Mansilla, Rushi Patel and Michelle Lozada, International Rectifier HiRel (IR HiRel), an Infineon Technologies Company, San Jose, Calif.

In space-rated power electronics, reliable attachment of surface-mount hermetically-packaged MOSFETs to printed circuit boards (PCBs) has been an elusive task for space system designers for many years. Material differences between the circuit board and surface mount device (SMD) package result in a mismatch between their coefficients of thermal expansion (CTEs). This CTE mismatch makes it difficult to maintain reliable solder joints between the PCB and the SMD package. This article will look at how IR HiRel’s advanced rad hard FET package design, the SupIR-SMD, solves these difficult challenges while enabling significant size, weight and power (SWaP) and cost advantages to the space power system design community. Read the article…

To overcome the CTE mismatch
between ceramic package and PCB,
IR HiRel adopted a package design
with a multiple-layer base.

Sponsored by Payton Planar Magnetics
A monthly column presenting information on power magnetics design, products, or related technology

Stored Energy In A Saturating Inductor Is Not Constant

by Gregory Mirsky, Design Engineer, Deer Park, Ill.

The behavior of magnetic components in saturation is a topic that is not always well understood. One misconception that I encountered recently was that the energy stored in a saturating inductor remains constant regardless of the magnetic core's status. However, in a previous work, I derived formulas that allow us to quantify the dependencies of both inductance and stored energy on magnetizing current. From those equations, we can demonstrate that the energy stored in the inductor does not remain constant in saturation as we’ll show in this article. This behavior is worth analyzing because inductors in various applications (such as solenoids and chokes) are frequently driven into saturation. The energy stored in the inductor is ultimately released and affects other components. Read the full article…


Compendium Untangles The Complexities Of PDNs

Power Distribution Network Design Methodologies, István Novák, Faraday Press edition, an imprint of Stairway Press, Apache Junction, Ariz., glossy hardback, 402 pages.

Reviewed by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

Experienced engineers know that the first 90% of a design project is relatively easy. This book addresses one of the topics in the last 10%, how to successfully distribute power on circuit boards. Run a few traces from the power connector to the loads and you’re done, right? István Novák, the author assembling the compendium of articles comprising this book, is an IEEE Fellow recognized for his contributions to the understanding of how to preserve waveforms in a noisy environment (“signal integrity”). This book, which has 22 chapters contributed by authors throughout the electronics industry, deals with the closely related field of power integrity. Read the full story…

A monthly column discussing standards and regulatory requirements affecting power electronics

One Month Left To Download EMC + SIPI 2021 Proceedings

by James Spangler, Contributor,

Due to COVID-19, the EMC + SIPI symposium was held virtually again this year, from July 27 through August 20, 2021. As always, this year’s conference program was full of useful information relating to EMC, signal integrity and power integrity topics. Members of the IEEE EMC Society were recently sent a reminder that they have until December 15, 2021 to access the conference proceedings here. If you are not a member of the EMC Society, but are already an IEEE member, you can join the society for a modest fee. See the society membership page. This article is a short overview and summary of the EMC + SIPI 2021 symposium to help you to navigate the workshops, tutorials and technical papers that are available in this year’s proceedings. Read the full article…


Texas Instruments’ TPS61094
buck-boost converter.

Buck-Boost Converter Boasts Low IQ And Supercapacitor Charging

 Photo: The synchronous bidirectional buck-boost converter with bypass switch provides a power supply solution for smart meter and supercapacitor backup power applications. Low IQ and supercap charging and discharging enable engineers to replace HLCs with less-expensive supercaps for peak load support and to extend battery life as much as 20%.

See the full story…

InnoSwitch3-PD offline
switcher ICs.

Flyback Switcher Chips With Built-In USB PD Controller Simplify Adapter Designs

 Photo: Members of this switcher IC family are said to offer the industry's most highly integrated solution for USB Type-C, USB Power Delivery (PD), and USB Programmable Power Supply (PPS) adapters.

See the full story…

Navitas Semiconductor’s
third-gen GaNFast power ICs.

GaN Power ICs Integrate Fast Overcurrent And Overtemperature Protection

 Photo: The third generation of GaNFast power ICs includes the company’s new GaNSense technology, which integrates critical, real-time, autonomous sensing and protection for both current and temperature.

See the full story…

More Power Products. . .

USB-C Controller Eases Transition Away From Barrel Connectors

Semiconductor Supplier Adds SiC Diodes To Portfolio

Automotive LED Driver Provides 4.5-V to 75-V Input


New on . .

Highly knowledgeable engineers contribute the in-depth tech articles you read in this newsletter. We recognize authors who are especially prolific as “Special Contributors.” Gregory Mirsky and Viktor Vogman have recently joined this esteemed group. Gregory has written extensively on magnetics design and circuit design topics, while Viktor has written extensively on power system architectures and server power supply design concepts. To access their articles, visit About Us and see “Who writes for”

The growing interest in wide-bandgap semiconductors is reflected in the increasing number of suppliers. How2Power’s just updated “Who’s Who In Silicon Carbide And Gallium Nitride Power Semiconductors” offers a listing of 30+ manufacturers of SiC and GaN discrete power semiconductors, ICs and modules. This list offers basic information on component types offered by each vendor. For those who want more details on specific components introduced by these companies over the years, see How2Power’s “SiC & GaN Power Component News.”


Qorvo, a provider of RF solutions, has acquired United Silicon Carbide (UnitedSiC), a manufacturer of SiC power semiconductors.

Renesas Electronics is delivering a synchronous boost converter solution in high volume for what’s described as the first at-home COVID-19 test authorized by the U.S. FDA.

Infineon and Hyundai Motor Group will nurture startups focusing on future mobility and digitalization.

PSMA has just released a white paper on “Energy Harvesting for a Green Internet of Things”.