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IN THIS ISSUE:
» Rad Hard MOSFETs Enable Easy Upgrade Of Flight-Proven DC-DC Converter
» Comparator Design: User-Defined Threshold With Asymmetrical Hysteresis
» Focus On Magnetics:
Determining Design Power Over An Input Voltage Range (Part 3): Maximum Transformer Power
» New on How2Power.com
FAE Confidential
» Book Review:
Classic Power Electronics Text—Updated, But Further Refinement Is Possible
» Spotlight On Safety & Compliance:
Why Aren’t Many Resistors UL Rated?
» New Power Products
» NSREC Notes: Space Power Components Answer Calls For Higher Performance, Lower Cost
» Industry Events
» Other Top Power News
From the Editor's Desk David G. Morrison
Editor, HOW2POWER TODAY
NASA’s exciting landing and deployment of its Perseverance rover on Mars last month kicked off an ambitious scientific mission that will search for signs of life, collect samples for return to earth, and even help prepare for a manned mission to Mars. While such groundbreaking activities astound us, closer to home (earth) there is a steady flurry of activity in space that’s become much more commonplace as SpaceX and others continually launch new satellites. A few thousand working satellites are said to be in orbit now, with thousands more to come. This activity continues to drive development of space electronics including improved power components. A feature in this issue by Andrew Popp and Bjarne Soderberg highlights improvements in rad hard silicon power MOSFETs, and the value newer devices bring to flight-proven power converter designs. As this article points out, it’s not just about improving converter performance, it’s also about limiting the need to requalify a design. For other examples of how power component suppliers are pushing the performance of rad hard components, see NSREC Notes in this issue. This newsletter also presents a feature on comparator design with relevance to power supply protection, a discussion of UL-rated resistors, derivation of design power formulas for transformers, and a review of an updated classic power electronics text. You’ll also find news about other conferences and components, and more in this edition of How2Power Today.
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HOW2POWER EXCLUSIVE DESIGN ARTICLES 
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Rad Hard MOSFETs Enable Easy Upgrade Of Flight-Proven DC-DC Converter
by Andrew Popp and Bjarne Soderberg, International Rectifier HiRel Products (IR HiRel), an Infineon Technologies Company, El Segundo, Calif.
Designing power electronics for space applications is often a balance between high reliability and risk. Design engineers look to develop architectures that meet mission requirements for cost and performance, balanced against acceptable risk levels for the mission. In this article, we will look at how a new generation of rad hard silicon MOSFETs enables efficiency and power density improvements in a heritage space-grade dc-dc converter. Specifically, we will examine how the use of IR HiRel’s R9 rad hard MOSFETs enables an increase in efficiency and power output capability in a flight proven dc-dc converter simply by replacing the previously used R5 rad hard MOSFETs and with minimal changes to the rest of the circuitry.
Read the article…
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A rad hard dc-dc converter that delivered
190 W of output using the R5 MOSFETs
can have its output power raised to 260 W
by swapping in the R9 MOSFETs, as
demonstrated in this article. |
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When applied in power supply
protection, asymmetrical hysteresis
provides for a speedy reaction at
overload, while allowing components
to reliably cool down upon removal
of the overload. |
Comparator Design: User-Defined Threshold With Asymmetrical Hysteresis
by Gregory Mirsky, Design Engineer, Deer Park, Ill.
When configuring a comparator circuit, it’s common to add hysteresis to the threshold to provide noise immunity. Typically, the designer sets a threshold with a single hysteresis value, so that in effect, there are high and low thresholds that are equidistant from the user-set threshold value. We’ll call this symmetrical hysteresis. However there are cases where we’d like to be able to configure a comparator for a threshold with asymmetrical hysteresis. For example, this approach is convenient for providing a reliable safety feature in power supplies incorporating voltage and current protection. This article presents a comparator circuit that can be used to implement asymmetrical hysteresis and derives the formulas required to set the threshold and two hysteresis values.
Read the article…
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FOCUS ON MAGNETICS
Sponsored by Payton Planar Magnetics
A monthly column presenting information on power magnetics design, products, or related technology |
Determining Design Power Over An Input Voltage Range (Part 3): Maximum Transformer Power
by Dennis Feucht, Innovatia Laboratories, Cayo, Belize
Magnetic components operated as transformers, like inductors, have maximum power ratings. But as was the case with inductors, the maximum power handled by the transformer is not optimal for sizing the transformer. The same analysis which we applied to inductors in parts 1 and 2 can be extended to transformers for the three configurations of PWM-switch converters as we’ll show here in this third and final installment in the series.
Read the full article…
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NEW ON HOW2POWER.COM
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FAE Confidential: If It Ain’t Broke, Let’s Break It!
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An applications team manager recalls the time a new VP tried to cut costs by moving the semiconductor company's Technical Response Center overseas.
Read the full article …
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BOOK REVIEW |
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Classic Power Electronics Text—Updated, But Further Refinement Is Possible
Fundamentals of Power Electronics, Third Edition, Robert W. Erickson, Dragan Maksimović, Springer, 2020, 1084 pages, PDF review copy, paper book: ISBN 978-3-030-43879-1.
Reviewed by Dennis Feucht, Innovatia Laboratories, Cayo, Belize
The authors of the third edition of this major work on power electronics are professors at the University of Colorado at Boulder and were students of Slobodan Ćuk and R. D. Middlebrook at Cal Tech. Anyone serious about power electronics will have a copy of this book, in some edition. But even for those who have an earlier version, I recommend obtaining a copy of this third edition for the new and necessary material it provides. I took a deep plunge into the second edition years ago. This review will focus on the third edition’s updates and some persisting weaknesses in the book, which mainly concern the theory on how to model current-mode control and methods of magnetics design. But first, a quick recap of what’s covered in this text.
Read the full story…
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SPOTLIGHT ON SAFETY & COMPLIANCE
Sponsored by Power Integrations
A monthly column discussing standards and regulatory requirements affecting power electronics |
Why Aren’t Many Resistors UL Rated?
by Kory Schroeder, Stackpole Electronics, Raleigh, N.C.
Electronics in various types of applications and markets will occasionally require a UL rating. UL recognition for a component can range from the flammability level, to a complex set of tests designed to demonstrate whether the part will fail without creating fire, explosion, significant heat, or other detrimental or dangerous results. When seeking resistors for such applications, our customers frequently ask, why aren’t there more UL-rated resistors available? This article discusses the cost factors that influence whether resistors carry a UL rating. It also explains how fusible, failsafe resistors offer an alternative to UL-rated components. But first, let’s look at why UL-rated resistors are considered for applications requiring a UL rating and where they fit in the two approaches to obtaining a UL listing for the customer’s end product.
Read the full article…
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 — POWER PRODUCTS IN 3 IMAGES OR LESS
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NSREC Notes: Space Power Components Answer Calls For Higher Performance, Lower Cost
by David G. Morrison, Editor, How2Power.com
Walking through the exhibition at the Nuclear & Space Radiation Effects Conference (NSREC), which is usually held in July, offers a unique opportunity to learn about the latest developments in radiation hardened and radiation tolerant components including the latest power semiconductors, ICs and modules. In 2020, conference planners shifted to a virtual event held in December. While it’s difficult to replace the experience of a live expo, NSREC exhibitors took advantage of the digital platform to provide updates on their developments through scheduled webinars, Zoom interviews and online chats. Companies used these resources to share information on the development of plastic-packaged parts, a higher-performance PWM controller for GaN power switches, smart power switch controllers, new point-of-load converters, and other component news.
Read the full story… |
INDUSTRY EVENTS |
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International Workshop On Integrated Power Packaging Presents Free Webinar Series
The International Workshop On Integrated Power Packaging (IWIPP) has announced the postponement of IWIPP 2021 until August 2022 due to the restrictions imposed by the COVID-19 pandemic. To maintain its charter of industry education, the PSMA and IEEE societies are sponsoring a free webinar series this coming August.
Read the full story… |
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PCIM Asia Will Showcase Latest Trends And Developments In Power Electronics
The PCIM Asia Conference 2021 will held alongside the PCIM Asia exhibition on September 9 - 11, 2021 in Shenzhen, China. PCIM Asia is a leading platform for sharing knowledge in the power electronics, intelligent motion technology, renewable energy and energy management sectors.
Read the full story… |
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PCIM Europe 2021 Will Go Digital
In light of the ongoing pandemic and challenging situation, numerous industry players have been hesitant to commit to an on-site event for PCIM Europe. For this reason, Mesago Messe Frankfurt has decided to hold a digital event.
Read the full story… |
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UW-Madison Presents Courses on Power Electronics, Machines and Drives
Starting this month, the University of Wisconsin-Madison will offer a series of seven, four-day professional development courses covering topics such as “Introduction to Electric Machines and Drives,” “Power Electronics Design Bootcamp,” and other topics. For more details, see the website. |
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 The European Power Supplies Manufacturers' Association is celebrating 25 years of operation with the launch of a new website.
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