1. APEC 2020 - It's Never Been a Better Time to be in Power Electronics
   
2. You Are Invited to the 2019 PSMA Planning Meeting
   
3. Meet Your Directors
   
4. About Our Members
   
5. Welcome to PSMA
   
6. Remembering Douglas McIlvoy
   
7. APEC 2020 Sponsors Continue Student Travel Support Program
   
8. PSMA Publishes the 2019 PSMA Power Supply Software/Firmware Reliability Improvement Report
   
9. PSMA and PELS Magnetics Committee High Frequency Magnetics Workshop
   
10. PSMA Capacitor Committee and IEEE PELS Capacitor Workshop: How to Choose and Define Capacitor Usage for Emerging Applications
    
11. Announcing EnerHarv2020 – Building the ecosystem for Powering the Internet of Things
    
12. The 7th Workshop on Wide Bandgap Power Devices and Applications (WiPDA 2019)
    
13. 2019 IEEE PELS/PSMA Phoenix Workshop on Packaging and Integration in Power Delivery (PwrPack) - An Exploratory Discussion Leading to PwrSoC2020
    
14. International Symposium on 3D Power Electronics Integration and Manufacturing: 3D-PEIM 2020
    
15. Welcoming You to the 23rd China Power Supply Society Conference (CPSSC 2019)
    
16. Forms vs. Function: Battling the Paperwork Deluge on Restricted Substances
    
17. Safe Power in Magnetic Resonance Imaging Environment
    
18. Events of Interest – Mark Your Calendar

If you or anyone in your company is interested in getting on the distribution list for future issues of PSMA UPDATE, please send e-mail to: power@psma.com. Be sure to include your name and the name of your company.

Previous issues of update: Q4_2018 | Q1_2019 | Q2_2019

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PSMA UPDATE is published and distributed via e-mail quarterly by the Power Sources Manufacturers Association. Send editorial information and comments to:

Permission to reprint information and articles as published is granted: a courtesy line is appreciated.

Membership in PSMA is open to any organization or corporation involved in the power sources and supplies industry. For membership information, visit our website or contact us by fax, telephone or email.

If you or anyone in your company is interested in getting on the distribution list for future issues of PSMA UPDATE, please send e-mail to: power@psma.com. Be sure to include your name and the name of your company.

 

he folks in New Orleans like to say, "laissez le bon temps rouler," that is "let the good times roll." And that certainly holds true for all of us currently in the power electronics industry. Never in the history of electronics has the contribution of power conversion been more in the forefront. Efficiency is a top priority of nearly every new design. And the latest advances in technology are touching virtually every aspect of our industry, from passive components to semiconductors and packaging. And there just isn't anywhere else on earth our industry comes together so completely to learn, connect and grow than at the Applied Power Electronics Conference. So, get yourself ready to let those good times roll at APEC 2020 in New Orleans next March.

The Call-for-Papers closed in July with over 1,000 digests submitted. Now the committee and over 100 volunteers have the task of peer-reviewing all the digests in preparation for the mid-year meeting in early October. At that time, the tough task will be to select the top 500+ papers for the program. Students with an accepted paper are encouraged to apply for APEC Student Travel Support. For more information, see the article on page 4 of this issue.

Work continues in development of the Plenary Session program. The committee has put together an exceptional roster of potential candidates. The program will be finalized before the next edition of this newsletter. The Plenary Session is expected to attract well over 2,000 attendees. In addition, IEEE.tv will, once again, be streaming the entire session, live, for those who can't make it to APEC by Monday afternoon.

By early September 2019, all the submissions of proposals for both the very popular Industry Sessions as well as the highly informative Professional Education Seminars will be under consideration. The Industry Session tracks that run in parallel with the Technical Sessions are expected to be as popular as ever.

At APEC 2019, over 1500 attendees arrived early to take advantage of the weekend and Monday morning Professional Education Seminars. The committee is planning for a repeat of this attendance in 2020.

The exhibit area for APEC 2020 has been expanded and it looks like the exhibit hours will be extended on Tuesday. As always, the APEC exhibits will be buzzing with the latest innovations to make your design job successful. The Wednesday Social Event will be held at Mardi Gras World with over 1000 attendees expected. It should be an interesting venue to view the many floats and costumes used during Mardi Gras events.

On the Saturday prior to the start of APEC2020, PSMA and PELS will again be sponsoring two workshops, the fifth High Frequency Magnetics Workshop and the third Capacitor Workshop. For more information see the articles on each workshop in this issue of the UPDATE.

Registration opens the week of October 28th.  Go to https://www.apec-conf.org/ to get all the information you need. In addition to making your reservation to attend, you will also be able to book your hotel accommodations. APEC has secured blocks of rooms at the close-in hotels to the convention center.  As usual, these rooms will sell out long before next March.

The entire APEC Conference Committee is excited about bringing our Premier Global Event in Applied Power Electronics to New Orleans, March 15-19, 2020. Laissez le bon temps rouler!

Provided by Greg Evans, APEC 2020 Publicity Chair

ll members of PSMA companies are invited to attend and to offer their inputs and suggestions for the projects and activities the Association should focus on in the coming year. The 2019 PSMA Planning Meeting will take place on Saturday October 5, in the Jackson Room at the Hilton New Orleans Riverside, New Orleans, LA.

The Board of Directors relies on the inputs generated at the Annual Planning Meetings to identify, consider and select programs for the following year that will bring benefits to the PSMA membership. For example, initiatives generated at recent Planning Meetings have resulted in the Power Supply in Package and Power Supply on Chip project and workshops, the Energy Efficiency and Safety & Compliance Database projects and the 3D Power Packaging projects and 3D-PEIM Symposiums.

This year's meeting will begin with a brief review of the year to date accomplishments and a summary of ongoing activities by Stephen Oliver, Chairman of the PSMA. This will be followed by an update of the six-quarter financial forecast from Treasurer Tim McDonald, and a status report and plans from the active PSMA committees.

Most of the meeting will feature an open forum to introduce and discuss possible special projects, initiatives, and priorities for the coming months. All members of PSMA Companies are encouraged to provide inputs. If you cannot attend the meeting in person, email suggestions to power@psma.com and they will be considered and included in the discussions. In the coming months, the PSMA Marketing Committee will summarize the results of the meeting and prioritize which projects and initiatives should be included in the focus for the next year.

All members and guests attending are invited to remain after the Planning Meeting to participate in a meeting of the Board of Directors, which will take place immediately following. After the Board Meeting, interested individuals are invited to tour the exhibit area space in the New Orleans Ernest N. Morial Convention Centerand the meeting room facilities planned for APEC 2020.

The APEC 2020 Technical Program Committee will meet the following day, Sunday October 6, to discuss the technical abstracts submitted and to organize the technical sessions, professional education seminars, rap sessions, and industry presentations for APEC 2020 in March. Since PSMA is a co-sponsor of APEC all members are invited to participate and contribute in this important activity.

To make your room reservations at the Hiltom, visit https://book.passkey.com/go/f1caf4f3 to receive the group rate of $175.00 USD plus taxes.

If you plan to attend the 2019 PSMA Planning Meeting, please email the Association Office at power@psma.com. We look forward to seeing many of you at these important meetings.

our members of the Board of Directors are elected at the PSMA Annual Meeting held every year during the APEC conference. Each Director serves a three-year term and is eligible to be reelected for one additional term.

At the PSMA Annual Meeting in March 2019, four new directors were elected to the PSMA board. Last issue we introduced you to Ada Cheng and Trifon Liakolpoulos. In this issue, we would like to introduce you to Ralph Taylor and Matt Wilkowski.

Ralph Taylor has a BSEE form North Carolina State University and is currently a Staff development Engineer at Delphi Technologies. His automotive career started with General Motors, Delco Electronics Division in 1979. He started in manufacturing development working as part of a team on the controls and software for high volume automated test and assembly equipment. (Radio testers, flip chip assembly systems, substrate assembly systems and an assembly robot for surface mount integrated circuits the fastest most repeatable robot ever tested by GM research). He then moved to advanced engineering where he was involved with controller design and software for various body and chassis systems. (Security systems, ABS controllers, Speed sensitive steering systems and window jam sensing system).

Ralph has been actively engaged in power electronics for Electric Drive Vehicles (EDVs) since 1990. He has been involved with system architectures and design of many EDV components, some of which are battery management systems, system controllers, that convert user inputs to torque commands, inverters for various EDVs including electric scooters, autos, heavy-duty trucks and off-road construction equipment and has been involved in architecting and designing power electronic systems for various demonstration electrified vehicles around the world.

He has been a Principal Investigator on several successful DOE Vehicle Technologies programs related to automotive power electronics. These programs include high temperature inverters and replacement dielectrics and manufacturing processes for DC link capacitors currently being used in electric drive vehicle inverters. He has 14 patents, has been inducted into the Delphi Technologies Hall of Fame and is a recipient of the Boss Kettering award (the highest achievable engineering award within the company). 

Ralph's experience with various programs and customers has allowed him to work with our national labs, universities and numerous research organizations related to advancing transportation power electronics. He has been involved with the Power Sources Manufactures Association (PSMA) for many years and is currently co-chair of the PSMA Transportation Power Electronics Committee.
 

Provided by Ralph Taylor, Staff Development Engineer, Delphi Technologies

Matt Wilkowski

Provided by Matt Wilkowski, Magnetics Technology Architect, EnaChip

 
aN Systems is the global leader in GaN power semiconductors with the largest portfolio of transistors that uniquely address the needs of today's energy-intensive industries including data centers, automotive, renewable energy, industrial, and consumer electronics. GaN Systems' award-winning power transistors are the building blocks of change for the design of a new generation of smaller, lower cost, and more efficient power systems that these markets now demand, and that are not possible with legacy silicon-based approaches. GaN Systems is dedicated to transforming transistor performance and delivering the innovation possibilities that come from unprecedented levels of energy efficiency.  This will enable companies to not only create wholly new kinds of products that impact their fiscal bottom-line, but also revolutionize their industries, and in the process, change the world's relationship with energy and its impact on climate change and delivering on the social values import to global citizens.

Products

Microchip delivers the next generation in digital power conversion with scalable solutions that solve problems in a wide range of applications.  Its power solutions range from microcontrollers performing supervision and sequencing for the most basic level of intelligent power control/integration, to the most advanced digital control topologies with digital control engines that integrate ADCs, digital control algorithms, and PWM generators to close the loop with firmware. Offering includes solutions for:

• Digital Control of Analog Regulators
• DEPA Controllers
• Core Independent Peripheral (CIP) Hybrid Power Controllers
• Full Digital Power using Microchip's dsPIC® Digital Signal Controllers (DSCs) for the highest available performance in applications with stringent efficiency requirements, including AC-DC or DC-DC converters and power inverters

High-Performance Analog/Mixed-signal ICs for Space

Microchip also offers a family of ICs through its Microsemi subsidiary that combine high-precision, ultra-fast regulation and high efficiency in a radiation-tolerant package.  Products include: 

• Space System Managers including position sensing and motor controllers and telemetry controllers 
• 8-Channel Source Drivers
• 8-Pair Diode Arrays
• Voltage Regulators and PWM

Power Discretes and Modules

GaN Systems has a wide breadth of innovative design tools, evaluation kits, and reference designs that make GaN easy to incorporate into power designs and expedite go-to-market system releases. Additionally, GaN Systems' Design Center has application notes, papers and presentations, and an online circuit simulation tool that allows designers to compare application conditions by implementing specific operating values.

Newer design tools include:

• Low current 3.5 A, 8A, and 11A device evaluation kit with EZDriveTM circuit, which eliminates the need for a discrete driver. The kit provides a low-cost solution that offers more design flexibility, reduces the number of components, and is easy to implement.

• 1.2kW and 3kW Bridgeless Totem Pole PFC reference designs. The designs implement 650 V E-HEMTs featuring an EMI filter and surge protection that can be utilized in applications such as data center power supplies to increase efficiency, reduce systems size, and reduce system BOM cost. The evaluation boards can also start up to full load condition.
  

• GaN Systems' 50 W, 100 W, and 300 W power amplifiers, small size, low cost, and high-efficiency evaluation boards are designed to support, simplify, and speed up the innovation of wireless power transfer systems. These kits combine GaN Systems power transistors with high frequency GaN E-HEMT drivers from pSemi and are designed to be consistent with AirFuel™ standards. It is targeted for lower power applications in industrial and consumer markets for items such as power tools, IoT devices, handheld terminals, medical devices and household robots.

MARKETS

Automotive
Two technology trends are playing a dominant role in the evolution of this transportation industry: electrification and autonomous driving. EVs are expected to grow to 125 million vehicles in 2035 and 500 million in 2040. In order to avoid electricity production and distribution from becoming the new villain of the transportation pollution (CO2) story, technology is needed that enables greater energy conversion efficiency in the vehicle and at the charging station.

GaN enables the design of smaller, more efficient (50% power loss reduction), and lower cost (20% less) power systems.

Data Centers
Eight million data centers around the world are needed to manage the 2.5 quintillion bytes of data that are created each day from individual and business uses. As much as 40% of their operating costs comes from the energy needed to power and cool their racks of servers. Increasing energy efficiency and addressing issues around power density has become an increasing priority for data center operators.

In the average data center, approximately 30% of power is wasted as it travels through the multiple power conversions necessary to go from the electrical grid to the micro-processors of an individual server. Along this route, significant energy efficiency and power density can be gained in three areas: UPS (universal power supply) from the outside grid into the data center, server rack power supply, and individual server power supplies.

Renewable Energy
The growth of power-reliant industries and the world's need to address climate change and pollution are transforming the demand for renewables from a secondary to a 24/7 constant source of power. More than 25% of global electricity generation is expected to come from renewable sources by 2020. Barriers to growth for the industry have come the lack of scalable and affordable technology solutions for the efficient conversion and storage of the power. Utility companies are no longer the sole providers of power, as reflected in the expected 17x growth in residential energy storage systems between now and 2023.

In comparison to Silicon transistor-based systems, the use of GaN technology provides a 50% efficiency gain (reduction in power loss) in the bi-directional power flow between the storage systems, the grid, and the location of use. This efficiency increase not only enables the design of smaller (30-50% smaller) and lower cost (10% lower) systems with greater power-density, but also provides opportunity for power provider revenue increases.

Industrial
Industrial markets as diverse as manufacturers, warehouse operators, agriculture, and mining facilities are searching for new levels of energy efficiency and the ability to overcome past design barriers relating to the size, cost, performance, and precision of their hardware. For the hundreds of millions of motors and motor drives, as well as the robots and robotics needed in their increasingly intelligent and automated industrial spaces – significant hardware innovation is an essential element of an ongoing global evolution.

Overall, industry accounts for 40-50% of global energy use.  But the more than 300M motors and drives that are incorporated today into robotic arms, conveyor belts, fabrication machines – are energy inefficient, wasting up to 30% of their power. The use of GaN technology in motor drive design delivers smaller (50% smaller), more energy efficient (30% increase),  lower cost (25% lower system cost) products.

GaN technology elevates the performance and utility of consumer electronics devices by increasing the energy efficiency, reducing size (5x smaller) and system cost of adapters, while also providing the opportunity to incorporate new features such as wireless charging at increased power levels (50x higher).

Provided by Jim Witham, CEO, GaN Systems

 
DK Electronics (previously EPCOS) develops, manufactures and markets electronic components and systems under the product brands of TDK and EPCOS, focusing on fast-growing leading-edge technology markets, which include automotive electronics, industrial electronics and consumer electronics as well as information and communications technology. Thanks to the 22,900 employees at some 20 design and production locations and an extensive sales network, the company is globally positioned – beyond the provision of standard products – to work closely with customers and create the right solutions for them.

The diverse range of TDK Electronics portfolio includes capacitors, ferrites and inductors, piezo and protection devices, as well as sensors.

Electronic components and systems are found today in almost every item of electrical equipment, where they are essential for guaranteeing perfect functionality. They perform key functions in cars and trucks, industrial machine tools and in electric railways, wind farms and photovoltaic plants, as well as in washing machines, LED lamps, smartphones, notebooks and televisions. In all these applications TDK Electronics solutions ensure the supply of power, protect electronic circuits and ensure their fault-free operation.

Capacitors are used in all fields of sensing, control and power electronics. They store electric charges and they filter currents and voltages. The portfolio includes aluminum electrolytic, aluminum polymer and film capacitors, whose main applications are in power supplies and converters. Power capacitors ensure a stable supply of power in electric trains, for example. In addition, power capacitors are the key components for the transmission of high-voltage direct current, which enables energy to be transmitted over long distances with minimal loss.

Inductors fulfill two basic functions of electronics, often simultaneously: the filtering of currents and the storage of electromagnetic energy. Ferrites, in turn, constitute the core of inductances and they bundle electromagnetic fields for the transmission of electrical signals and power. Inductors are used, among other things, in switch-mode power supplies for information and communications applications, as well as in automotive, industrial and entertainment electronics.

TDK Electronics also manufactures components that ensure electromagnetic compatibility and, consequently, the fault-free operation of all types of electronic equipment.

Piezo and protection devices protect electronic circuits against voltage spikes and current surges. The portfolio includes surge arresters and switching spark gaps, thermistors, varistors and a comprehensive array of multilayer components that include piezo-actuators, as well as CeraDiode® varistors, the extremely thin CeraPad® substrate with integrated ESD protection, and CeraLink™ capacitors. These components are essential, above all, in vehicles, industrial equipment and household appliances, but also in power engineering, and smartphones, tablets and wearables. Among the latest product highlights are PowerHap™ piezo actuators with haptic feedback, CeraPlas™ for the generation of cold plasma, and CeraCharge™, the world's first rechargeable solid-state SMD battery.

Sensors and sensor systems include temperature sensors, which, for example, are used in vehicles in systems for reducing emissions. Such components are also used in household appliances and industrial plants. To these must be added the pressure sensors and transmitters that are required primarily for the monitoring and diagnosis of pneumatic and hydraulic systems and for the control of valve and filter systems. One further field of application is medical technology, such as the machines for measuring blood pressure or for artificial respiration. Rounding out the portfolio of sensors is the Tronics product spectrum, which consists primarily of inertial sensors that, among other things, are able to sense acceleration and rotation.

More about our TDK Group Technologies, please visit: https://www.tdk.com/corp/en/about_tdk/our_ideas/index.htm

Provided by TDK Electronics

Editors Note: We would like to feature your company in a future issue of the Update. Please contact the Association Office for information about how to submit an article for consideration.

West Coast Magnetics
Jacob Campbell
4848 Frontier Way, Suite 100
Stockton, CA 95215
Telephone: 209-944-0836
E-mail: JCampbell@WCMagnetics.com
Website: https://wcmagnetics.com/

West Coast Magnetics designs best in class transformers and inductors and provides manufacturing services for electronic products with high engineering content. Their active R&D has resulted in new patented technology and innovative designs for power and RF magnetic components in many applications. West Coast Magnetics continually redefines what is possible with magnetic technology. Headquartered in the San Francisco Bay Area, WCM manufactures and designs custom engineered magnetic components, and provides manufacturing services for companies competing in the global OEM space. They have manufacturing facilities in Stockton, California and in Tecate, Mexico.

t's with a heavy heart to report the passing of Douglas "Doug" McIlvoy. Doug passed away on August 28th due to complications from a recent heart operation.

PSMA first came in contact with Doug when he was the vice president of OECO Corporation in Milwaukie, OR. He later led a management buyout of the business in 1995 after serving there for 26 years. Years later he founded VXI Electronics and Power Electronics Strategies while staying active in our industry. One of his early volunteer responsibilities was serving as PSMA Industry-Education Committee Co-chair.

Don Staffiere and Doug McIlvoy

A very early member of the PSMA, Doug wore many volunteer hats in broadening the recognition of PSMA over the years. He was part of the team engaged in the PSMA relationship with the Applied Power Electronics Conference (APEC) and the merger of APEC with the IEEE PELS and IEEE IAS societies.

Doug became a member of the PSMA Board of Directors in 1990 and served as Vice President in 1995 and later as PSMA Chairman in 1996-1997. After leaving the Board, Doug continued to serve as a member of the PSMA Advisory Council.

Doug served as APEC Program Chair in 1993 where the Conference and Trade Show was held in San Diego. The following year he was General Chair of APEC 1994 held in Orlando.

Being in the "power" industry it is no surprise to learn that Doug enjoyed working on muscle and sports cars when he was younger. My kind of guy.

Doug's family includes his wife Beth, 3 sons (Sean, Scott, Lane), step-daughter (Missy Chartier), 6 grandchildren, 3 great grandchildren and his sister Sheila Warmuth.

A memorial service will be held on Saturday September 21 at 11:00 at the Highland Baptist Church in Redmond, Oregon.

Provided by Larry Gilbert, former Board Member PSMA, APEC and IEEE Working Group Chairman.

Travel support of up to $1,000 offered to graduate and undergraduate students enrolled in
power electronics programs to assist in their attendance at APEC in March 2020;
Up to $60,000 in travel support will be distributed; Deadline for applications is Oct. 25, 2019

he joint sponsors of the Applied Power Electronics Conference (APEC) have announced the continuation of the popular Student Attendance Travel Support Program of up to $1,000 to cover a portion of the travel and conference expenses for as many as 60 students to attend APEC 2020 in New Orleans, LA, March  15-19, 2020. Interested students must apply by October 25th, 2019.

In its 15th year, this popular program, initiated by the Power Sources Manufacturers Association (PSMA), is now jointly underwritten by PSMA and the other co-sponsors of the APEC conference: the IEEE Power Electronics Society (PELS) and the IEEE Industry Applications society (IAS).

The recipients will be chosen by the APEC 2020 Student Travel Support Committee. Application forms are available at APEC Attendance Travel Support Application. The application criteria are:

• The applicant must be an undergraduate or graduate student enrolled in a power electronics program at an accredited institution
• Only students who have not received travel support in the past will be considered
• The recipients must be an author or co-author of a paper that was accepted for presentation at APEC 2020
• The recipient must attend APEC 2020 and submit expense receipts to the Committee for reimbursement
• Applications must be made and received by the Committee by October 25, 2019
• The recipients will be notified by the Committee by November 15, 2019

As part of the application process, students must provide information about their educational institution, degree program, the name of their faculty advisor and a brief description of their career interest and reasons for planning to attend APEC. The application also requires the title and ID number of their accepted APEC paper, as well as the name(s) of the co-author(s).

More information about the APEC Student Attendance Travel Support Program may be found at the PSMA's Education Forum page.

Comprehensive Study on Digital Implementations of Power Supplies Commissioned by
the PSMA Board of Directors and Executed by the PSMA Reliability Committee

Power Electronics are transitioning from analog control to digital control. Power supply designers now need to create and embed software in power supply products.  Moving from power electronics with analog control to power electronics with digital control is a significant transition and the 2019 PSMA Power Supply Software/Firmware Reliability Improvement Report attempts to present key findings related to the challenges and solutions to reliability in the digital control of power electronics.  

"Software reliability is the ability of software to repeatedly perform intended functionality for defined operating conditions over extended periods of time. While the focus here is on software reliability, hardware variations and evolution over time impacts software reliability and legacy software function. High quality software with high reliability requirements is typically implemented following a standards-based regulatory process," noted Brian Zahnstecher, Co-Chair of the PSMA Reliability Committee. Tony O'Brien, Reliability Committee Co-Chair, added "Software engineering best practices are being adopted for digital power electronics control for power supplies to ensure reliability does not suffer with the transition to digital control. Some of the best practices are relatively new, evolving and unfamiliar to the power electronics world."
 
Report Structure
This report examines a wide array of problems and challenges in the field of digitally controlled power supplies, then proceeds through observed and proposed improvements and best practices. The report includes sections on:

• The typical issues, challenges, and points of failure in digitally controlled power supplies.
• Best practices that are useful for high quality digital power electronics.
• The quality of software in digital power electronic power supplies.
• Guidance on design process improvement, allowing development to move toward best practices; some standards from related and comparable product sectors using processes to achieve high quality software are introduced.
• Various specifications and templates that support best practices and quality.
• Program management and integration of different engineering cultures and tools to create reliable product.
• A range of tests, inspections, types of analysis, plans, and tools that support developing high-quality product.
• Key metrics from both power hardware and software control backgrounds.
• New metrics that might benefit the power supply industry.

A copy of the printed and USB memory drive versions of 2019 PSMA Power Supply Software/Firmware Reliability Improvement Report will been sent to PSMA Regular member companies as a benefit of their membership. Additional copies may be purchased at the member price of $US290. PSMA Affiliate members may also purchase the report for $US290. The report is available to non-members for purchase on the PSMA website (www.psma.com) for the price of $US2490.

Power Magnetics @ High Frequency
Saturday March 14 2020
Prior to APEC 2020
Ernest N. Morial Convention Center
New Orleans, LA 70130

he PSMA Magnetics Committee and IEEE PELS will conduct the fifth "Power Magnetics @ High Frequency" workshop on Saturday, March14, 2020, which is the day before and at the same venue as APEC 2020 in New Orleans, LA.

The purpose and focus of this workshop is to identify the latest improvements in magnetic materials, coil (winding) design, construction and fabrication, evaluation and characterization techniques and modelling and simulation tools. This is to target the advancements that are deemed necessary by the participants for power magnetics in order to meet the technical expectations and requirements of new market applications for higher operating frequencies and emerging topologies that are being driven by continuous advances in circuits topologies and semi-conductor devices.

The target audiences for the 2020 Power Magnetics @ High Frequency workshop include the designers of power magnetic components for use in electronic power converters responsible to implement the most technologically advanced power magnetic components that are necessary to achieve higher power densities, specific physical aspect ratios such as low profile, higher power efficiencies and improved thermal performance. The target audiences also include people involved in the supply chain for the power magnetics industry ranging from manufacturers of magnetic materials and magnetic structures, fabricators of magnetic components, providers of modelling and simulation software as well as manufacturers of test and characterization equipment.

The 2020 Power Magnetics @ High Frequency workshop will open with a keynote presentation and several lecture presentations regarding characterization and modelling of power magnetic components. In addition to the brief Q&A period after each individual presentation there will be a panel of the presenters at the end of the session to address topics requiring more detail as deemed by the workshop attendees.

During breakfast, lunch and the networking hour at the end of the workshop there will be an interactive session of tabletop technology demonstrations addressing specific technical disciplines and capabilities consistent with the workshop agenda. Interaction between the attendees and the presenters is highly encouraged during this portion of agenda as a segue from the opening keynote presentation and the technical issues session.

If anyone would like to participate as a presenter for the technical demonstration session, please contact the organizing committee through PSMA by e-mail to power@psma.com with a description of your proposed technical capabilities topic.

Based upon responses to the survey from the 2019 workshop, the afternoon session of the 2020 workshop will be a series of technical presentations addressing topics associated with different winding techniques used to fabricate power magnetic components. In addition to the brief Q&A period after each individual presentation there will be panel of the presenters to address topics requiring more detail as deemed by the workshop attendees.

The specifics for the workshop structure and the presentations for the workshop are currently in progress and are not finalized. If anyone can support a strong position for a specific topic that would be of general interest to the magnetics and the power industries, please contact the organizing committee through PSMA by e-mail to power@psma.com .

More details regarding the agenda for the workshop as well as registration for the workshop will become available on the PSMA website (www.psma.com/technical-forums/magnetics/workshop) over the coming months.

Organizing Committee

Steve Carlsen, Raytheon Systems Company
Ed Herbert , PSMA
Jenna Pollock, SF Motors
Rodney Rogers, Allstar Magnetics
George Slama, Wurth Elektronik
Fred Weber, Future Technology Worldwide
Chuck Wild, Dexter Magnetic Technologies Inc.
Matt Wilkowski, EnaChip

 

How to Choose and Define Capacitor Usage for Emerging Applications
Saturday March 14 2020
Prior to APEC 2020
Ernest N. Morial Convention Center
New Orleans, LA 70130

he PSMA Capacitor Technical Committee and IEEE PELS are jointly Sponsoring the third pre-APEC Capacitor Workshop on Saturday March 14, 2020, the day before the conference begins, at the New Orleans Convention Center. The 2020 workshop follows up the successful Workshops in 2018, and 2019. Feedback from the previous workshops showed that these events delivered valuable insights to attendees and provided ideas for what topics to address in the 2020 workshop around Capacitors, their technologies and applications. The workshop is designed to bring value to everyone, from newcomers to advanced designers of DC-DC converters, frequency drives, inverters, and other power conversation applications.

The workshop organizing committee has a clear mission:

The PSMA Capacitor Committee/ IEEE PELS Annual pre-APEC Workshop will educate the attendees on capacitor trends, technologies, and innovations. Wherever and whenever applications need energy, Capacitors are at the spotlight, and as energy moves the world it is incumbent for everyone to keep their finger on the pulse of capacitor issues. The PSMA/PELS Workshop Organizing Committee is committed to present the best material available to meet the industry's needs.

Since APEC 2020 is fast approaching, now is the time to plan to attend! Capacitors represent two thirds of the overall passive components market, and the generic importance of capacitors in the electronic world is well known - but sometimes not well understood. In addition, the changing product landscape with the painful situation in 2018 with the massive MLCC undersupply has challenged many designers and product planners. Make your plans to participate in the Pre-APEC 2020 Capacitor Workshop and enhance your knowledge and productivity.

The Pre-APEC 2020 Capacitor Workshop will focus on a number of topics from Aerospace and Aeronautics to Automotive and eMobility. Representatives from world Class Manufacturers and technical specialists will also spotlight on the challenges of wideband trends and new telecommunication standards like 5G as well as providing insights into the latest capacitor technologies and trends attendees should be following. Engineers with broad hardware development experience will discuss the most efficient designs for SMPS' and also focus on how to prevent EMI issues. Researchers from universities and institutes will dive into the future of capacitor technologies and present what comes next. All of the presentations will focus into the workshop headline: "How to choose and define capacitor usage for emerging applications, wideband trends, and new technologies".

The presenters of this workshop are all experts coming from various backgrounds ranging from worldwide leading capacitor manufacturers, international universities, and technical institutions. In addition, many of the presenters are industry experts in designing circuits and applications, as well as specialists in the manufacturer of capacitors. They will provide a broad range of insights, news and relevant information to help you apply the best solutions in your daily work with capacitors. As capacitors are the most used components in the electronic world, establishing common terminology and identifying their behavior in finding the "best fit solution" are the main goals of this workshop. With a deep dive into state-of -the- art for materials and components, a roadmap of technologies and an application roundup, attendees will gain value and benefits from this workshop. in many ways.

The organizers of the Workshop aim to have a perfect balance between practical content delivered by capacitor manufacturers mixed with content offered by worldwide leading universities and their lectures on future capacitor research & development. Surrounded by keynotes of forward thinking market players the interactive sessions at the Workshop promise to deliver a fruitful package to attendees.
To round up this workshop and make it more beneficial, there will be demonstration stations available during breakfast, lunch and the afternoon networking session to add practical backgrounds to the topics discussed in the presentations. Specialists in applications and measurements will be available to answer questions on capacitors and their applications. Finally, there will be a reception during the closing demonstration session with snacks and drinks to provide additional informal networking opportunities. Continuing education credits will be available to workshop attendees.

The latest agenda, registration, and additional information will be available at www.psma.com/technical-forums/magnetics/workshop.

Provided by members of the Capacitor Workshop Organizing Team:

Pierre Lohrber, Wurth Electronics
Fred Weber, Future Technology Worldwide

16-18 June 2020
ASSIST Center, North Carolina State University

he inaugural EnerHarv2018 International Workshop on Energy Harvesting and Micro-Power Management, was hailed as a major success with participants (and indeed those who missed it!) eagerly asking 'when is the next EnerHarv?' PSMA is now pleased to provide the answer to this, announcing that EnerHarv2020 will held from 16-18 June 2020 in Raleigh, North Carolina, USA and will be proudly hosted by Center for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST),  at North Carolina State University (NCSU). From EnerHarv2018 we saw the value in bringing a broader range of stakeholders to our ecosystem (e.g. packaging, software, industrial design) and the critical need to bring in more end users across multiple applications (building management, medical technologies, assisted living, environmental, conditional monitoring of equipment, systems, power supplies). This strongly influenced our decision to host the event in the Raleigh/Durham area, where there is already a hotbed of industrial and academic activity and a collaborative, existing ecosystem in place via the ASSIST Center.

As for EnerHarv2018 the mission remains unchanged, to create 'a focal point for a community of experts and users of energy harvesting & related technologies to share knowledge, best practices, roadmaps, experiences and create opportunities for collaboration.' It demonstrated a need for technology and thought leadership in this sector and the potential benefits of emerging technologies, if properly guided and integrated. It cross connects not just suppliers and developers of power electronics components and systems but also demonstrates the power of collaboration when experts from power electronics, ICT and MEMS co-develop standardized, inter-operable and system optimized solutions for real life applications. The ecosystem has grown substantially since the last event to increasingly address the challenges of powering 1 trillion sensors the world will have by 2025, offering unprecedented growth opportunities for developers and integrators of power electronics parts and systems.

The workshop will mainly (but not exclusively) be dedicated to making portable power sources last longer for ultra-low power IoT edge devices. Ideally, devices can be powered indefinitely using energy harvesting, where ambient energies are available, but at the very least embedding technologies that minimize the power consumption and maximize the conversion efficiencies.

Moving the event to the US this time shall make it more accessible to many more on the user/implementer side of the industry o compliment the healthy representation from the supply side Attendees will learn of the many constituents of an existing, energy harvesting/micro-power management product ecosystem and how to apply these products to their application requirements in a system optimized way.  They will also learn valuable information to drive optimal design execution and address common pain points in bringing a variety of products to market which will enable a dramatic penetration of energy harvesting solutions into a broader range of applications.

Through networking, attending tutorials, viewing real life demos and participating in discussions, developers will gain a step function increase in their knowledge and ability to develop/gain access to energy harvesting powered solutions. The workshop will demonstrate examples of successful energy harvesting products already created via synergies between the energy harvesting source and the load demand developers.

 EnerHarv2020 will be supported by the EU EnABLES project (No. 730957), which is already building an international 'power IoT' community comprising almost 300 academic and industry stakeholders and already seed funding feasibility studies and providing free of charge access to expertize and facilities across leading research institutes in Europe.  Numerous other, sponsoring organizations shall be announced following along the tradition set by EnerHarv2018.

An opportunity not to be missed for anyone interested in 'powering the internet of things.'  

In future newsletters we will provide further details on the event including the organizing and technical committees, sponsors, outline program an initial speaker line up. In the interim, if you would like to learn more or get involved please contact the PSMA Energy Harvesting committee co-chairs Mike Hayes (General Chair, michael.hayes@tyndall.ie) or Brian Zahnstecher (Technical Chair, bz@powerrox.com).

Provided by PSMA Energy Harvesting Committee Co-Chairs

Mike Hayes, Tyndall National Institute
Brian Zahnstecher, PowerRox

reparations for the 7th Annual IEEE / PSMA Workshop on Wide Bandgap Power Devices and Applications (WiPDA ) are well underway.  This year's event will be held at the Marriott Stateview Hotel, which is located on North Carolina State University's campus in Raleigh, North Carolina.  From October 29 to 31, the workshop will offer one day of tutorials and two days of technical presentations that include plenary speakers, panel discussions, 12 technical tracks consisting of 48 oral presentations, and a poster session. 

There will be five 80-minute tutorials on October 29, 2019. Two happen during the morning session after breakfast; one covers the design of silicon carbide (SiC) circuit breakers and the other discusses using simulation while designing power modules and its impact on development time in the laboratory.  Three sessions will take place after lunch.  The first presents SiC and gallium nitride (GaN) based Switched-Tank Converters for data centers and electric vehicles.  The second tutorial describes best practices for using voltage acceleration to determine the reliability of GaN devices.  The final presentation covers the application of 10 kV to 15 kV SiC power devices in soft and hard-switching medium voltage converters.  More information about the tutorials is available on the workshop's website (https://wipda.org/tutorials/). 

The Welcome Reception follows the tutorials. It will be a casual evening with drinks and hors d'oeuvres open to all the WiPDA attendees.

The workshop formally begins on October 30, 2019 with two plenary presentations in the morning.  These are followed by two panel sessions: "GaN Power Device Market Adoption – What is the Status and What are the Barriers and Accelerators to Market Penetration," and "Challenges and Opportunities for SiC in High Power Applications."

After a lunch break, three more plenary presentations take place.  Subsequently, the day's technical sessions begin. Each session comprises three parallel tracks, with each track consisting of four presentations. The topics are SiC applications, GaN devices, and SiC devices.  The evening wraps up with the poster session, which is supported by JEDEC, and the workshop's banquet that is supported by Wolfspeed.

The last day of the event, October 31, 2019, begins with the final three plenary presentations.  Then there will be three more technical sessions covering nine tracks.  Three focus on SiC applications, two on GaN applications, two on SiC devices, one on GaN devices, and a special track on emerging technologies.

Sponsors and Exhibitions:

This year's workshop is made possible thanks to our three Platinum Sponsors: Applied Materials, Infineon Technologies, and Wolfspeed.  Additional support is provided by the IEEE Power Electronics Society (PELS), the Power Supply Manufacturer's Association (PSMA), the IEEE Electron Devices Society (EDS), and PowerAmerica.  The workshop is also happy to host eight exhibitors along with our sponsors.  The exhibition runs during the conference.
There are still opportunities for companies to participate in the workshop.  Exhibition booths are available for showcasing products and networking with potential clients and customers.  Sponsorship opportunities are still available for businesses that want to be affiliated with the event.  More information is on the workshop's website at: http://wipda.org/exhibition-sponsorships/.  E-mail inquiries to exhibitsatwipda2019@gmail.com.

Registration:

Attendees can register at the workshop's website (https://wipda.org/registration/).  The advanced registration period ends September 20, 2019.  Afterwards, regular rates apply.  A block of rooms is set aside for attendees at a preferred rate of $159 per night plus taxes and local fees.  More information is available at https://wipda.org/venue/. 

For additional questions about the workshop, please contact wipda2019@gmail.com.  We look forward to seeing you in Raleigh at WiPDA 2019 this October.

Provided by Mark Scott, WiPDA 2019 Publicity Chair

An Exploratory Discussion Leading to PwrSoC2020
Oct. 31- Nov. 1, 2019
Skysong Innovation Synergy II, Arizona State University

This Workshop uniquely spotlights technology and manufacturing advancement of
miniaturization and integration of power conversion and power management solutions.

he Power Sources Manufacturers Association (PSMA), in partnership with IEEE Power Electronics Society (PELS), is sponsoring a Workshop on Packaging and Integration in Power Delivery at Arizona State University's SkySong Innovation in Scottsdale, AZ October 31-Nov. 1, 2019. This two half-day event is An Exploratory Workshop Leading to the 2020 International Workshop on Power Supply on Chip (PwrSoC), in Philadelphia, PA.

In recent years, the overall form factor of power electronic devices have scaled-down significantly for a broad range of applications and power levels. This two-half day workshop will focus on two topics related to power delivery in a package:

1. Power system in package (PSIP) power modules
2. Process and integration of multi-die power delivery in package.

Invited speakers from both industry and academia will  address the challenges and opportunities in miniaturization and efficiency power delivery  in  application areas. Each session will consist of presentations followed by active discussions between IC designers, assembly experts and substrate/materials providers bringing innovative solutions to address the packaging challenges in power delivery products.
The workshop will be held at Arizona State University's SkySong Innovation in Scottsdale, AZ. The General Chair is Professor Hongbin Yu from ASU's School of Electrical, Computer and Energy Engineering, who has participated in many of the prior PwrSoC workshops.The Technical Program Chair for the workshop is Jim Doyle from Dialog Semiconductor, who was a keynote presenter at the PwrSoC2018. The support team for the workshop includes Arnold Alderman representing PSMA, Francesco Carobolante representing IEEE PELS, and Prof. Hanh-Phuc Le, Dept. of Electrical, Computer, and Energy Engineering, the University of Colorado at Boulder who is currently IEEE PELS Topic 2 Committee Chair.

Workshop General Chair Professor Hongbin Yu commenting on this workshop's venue: "We are excited to have this workshop in Phoenix area, where there are many microelectronics companies that are very active in developing new semiconductor devices that  require innovation in the scaling of power integration and provide much-improved efficiency. Through this workshop, we hope to foster much stronger collaboration between academia and industry resulting in new and key contributions in power delivery innovations."
Technical Program Chair Jim Doyle from Dialog Semiconductor points out "The workshop will bring together technical experts on SOC packaging mainly from the Phoenix area. The line between pure integration and multichip SIPs have become blurry since processes such as InFo, MCeP,WLP/RCP,WL-esip, 3D TSV offered by different foundries and packaging companies, provide effective solutions competitive with full integration.  These options could revolutionize the decision to integrate or not to integrate. Join us to learn more about the options and trade-offs."

See the completeprogram at the workshop website: http://pwrsocevents.com/pwrpack-workshop-at-asu/

Registration will be open until October 31st, 2019, and is available through the workshop website.

Sign-up for a Partnership Opportunity by sending an email to yuhb@asu.edu, or Jim.Doyle@diasemi.com

There are two levels of company partnerships available:

• Platinum level provides an exhibit table for the duration of the workshop, two free registrations to all events,  plus the Gold-level banner and logo display opportunities.
• The Gold level provides one free registration to all events,  provides company visibility through banner, logo displays at workshop events, in the technical program, in website and announcement emails.

	Provided by:
Hongbin Yu, General Chair				Jim Doyle Technical Program Chair

June 22-24, 2020
Osaka University, Japan

PACKAGING is a Design Function
MANUFACTURING provides the Design Rules

The conference will feature invited lectures highlighted by a keynote addresses from Industry experts.  There will also be tutorials, technical sessions that include contributed presentations, exhibits, and an interactive poster/demonstration session. The symposium is being organized by the Power Sources Manufacturers Association (www.psma.com), and will be chaired by Prof. Tsuyoshi Funaki of the Osaka University, Japan.

Session topics during the 3-day symposium include:

• Systems Integration & Thermal Management
• Multiphysics Design and Tools
• Materials
• Manufacturing Technologies: equipment and processes
• Heterogeneous Integration of Components
• Quality & Reliability

University of Osaka School/Graduate School of Engineering

Osaka is located in the center of Kansai region, facing Osaka bay. About 9 million people live in Osaka, the largest component of the Keihanshin Metropolitan Area, the second largest metropolitan area in Japan. Osaka was historically developed as a town of merchants. It has also been known as the nation's kitchen. Osaka contains numerous urban canals and bridges, including its most famous urban canal, Dotonbori. Osaka Castle, one of the most famous landmarks in Osaka, played a major role in the Japanese history.

The Symposium will include a table top exhibition area. Interested organizations are invited to purchased exhibit space that will include a table to exhibit products and literature to a target group of technologists. Symposium Sponsorship is also available which includes one registration, tutorial registration, an exhibit table, Website and program recognition, lecture room recognition, and a banner displayed in the lecture room. Interested in being an exhibitor or sponsor of 3D-PEIM 2020, contact info@3d-peim.org.

Call for Papers coming in October. Visit http://www.3d-peim.org/call-for-papers/ for information when available.

If you are interested in learning more, please contact info@3D-PEIM.Org, or the PSMA office at power@psma.com.  We look forward to seeing you in Osaka university this coming June 2020.

Prof. Tsuyoshi Funaki Osaka University General Chair, 3D-PEIM Symposium 2020

Prof. Katsuaki Suganuma, Osaka University, Technical Program Co-Chairman

he China Power Supply Society Conference (CPSSC) is considered the largest, highest-level academic event of power supplies in China. With a history of more than 35 years, it has a broad impact on the power industry. Renowned professionals, senior executives from industry and government departments and graduate students at home and abroad converge on the CPSSC to share and exchange new theories, new technologies, and new achievements in varies fields of power supply.

CPSSC 2019 will be held in Shenzhen, China on Nov. 1-4, 2019. This year the conference includes 524 papers and is expected to attract over 1,500 attendees. CPSSC' 2019 will feature a comprehensive technical program including plenary sessions, tutorials, technical sessions, industry sessions, poster sessions and over 100 exhibitors.

3rd CPSS & PSMA Joint Workshop on Power Supply Technology Innovation

Prof. Dehong Xu, President of CPSS (Right) and Stephen Oliver, Chairman of PSMA (Left)

On November 3, during CPSSC' 2019, CPSS and PSMA will hold the 3rd Joint Workshop on Power Supply Technology Innovation from 14:00 – 17:00 at the Shenzhen Yunshan Tianyuntian International Hotel. This workshop aims to promote exchanges and cooperation between American enterprises and Chinese enterprises; facilitate communication and discussion on the trend of power supply industry according to the present development of the industry of China and the US. There will be several presentations from both PSMA and CPSS, each followed by a 5 minutes Q&A and will conclude with a networking social. The workshop will be in English (the overall CPSS conference language is Chinese).

The Workshop Chairs are Prof. Dehong Xu, President of CPSS and Stephen Oliver, Chairman of PSMA. There will be an estimated 100-120 participants at the workshop, including senior leaders from both CPSS and PSMA, senior managers and technical managers of Member companies from both organizations from China and the US.

lmost once a week or more, the phone rings or an email arrives, usually from a top name brand company or on behalf of one, asking about our product's compliance with environmental and hazardous materials regulations. I [Kevin] work for a semiconductor manufacturer, so the requests concern components we're supplying to a customer. But anyone supplying any components, subassemblies or finished electronic instruments or equipment could be subject to such inquiries. The request comes from a far-off land, because it's been outsourced to someone to get a form filled out. It seems this is more fun and monkey motion from our friends in corporate finance and legal departments. 

The good news is that people are paying attention to restricted materials regulations. However, the bad news is that these OEM customers are unwilling to subscribe to a supply-chain service such as SiliconExpert, which would allow them to have all the necessary materials information at their fingertips. They probably figure it is less money to get their suppliers to do it for free, using telemarketers to ask us to fill out an extensive check list that someone dreamed up as the standard for the Mr. Big company. The intention was to get every supplier to fill out this form with the same info on it.

The problem is compounded by the fact that different individuals working for the same company will contact us at different times asking us to fill out forms for different parts. As a supplier we have even asked them, "Can you send us a list of all the parts you use at one time so we can work on a complete list for you?" The response has been, "No, all I have here is part ABC123. Please fill out the form." Next week they call back with another part and don't even know their company asked us for something else last week. The process is usually not very organized.

Naturally, as suppliers we balk at these requests. After all, the information the customer is requesting has already been published on our company's website. So, we try to point the customer there. However, almost every attempt at telling them "here are the links which list all the information you are requesting," results in them responding, "yes but you must fill out our form in our format". What they don't say is why they insist we fill out their form. If they did, the answer would be "because I have no idea what any of this means and I will be calling people next week asking them for compliance information relating to health insurance."

Then too, we can't help fill out everyone's form because each one is different. But wouldn't it be nice if we had a standard form everyone could agree on? Maybe EICA (the Electrical Industry Certifications Association) or some other organization could establish a standardized form to simplify our lives a bit? While we wait for such a form to be developed, in the spirit of helping (without the ability to fill out every possible form that might cross your desk), we offer the following list of materials resources (see the table). These are the websites for the various global regulations that your customers may ask you about and these sites provide the information you'll need to help you fill out the RoHS, prop 65 Reach, and plethora of other requirements concerning restricted materials.

As noted previously, these regulations are not just for semiconductors. They apply to all components including passive electromechanical devices, cable assemblies, connectors and any parts going into an assembly. That includes hardware, plastic cases, rubber feet, purchased assemblies, batteries, power supplies and anything that goes into the box that you ship your product in. And they also mean the box, plus line cord and packaging materials—even the user's manual!

If you supply any of these items to a company that makes a product, then your product must be cleared for compliance with the targeted regulations, and you are required to fill out the tick box check list that company needs. This activity may not be fun, but visiting the regulatory websites and getting familiar with the requirements may take some of the pain out of the process.

Kevin Parmenter Director of Applications Engineering Taiwan Semiconductor America

Jim Spangler President Spangler Prototype Inc. (SPI)

Editor's Note: This article was first published in the July 2019 issue of How2Power Today (http://www.how2power.com/newsletters/index.php).

rom the smallest to the largest, all electronic equipment requires power supplies, and with the increase in the amount of wireless connected devices deployed in the medical environment, electromagnetic compatibility (EMC) has become a big concern for all users. In the vast majority of applications the power supplies' EMC is manageable, but in some extremely demanding areas such as Magnetic Resonance Imaging (MRI), the challenges for power supplies manufacturers are twofold, not to disturb the sensitive equipment, but also not to be disturbed by the multi tesla (T) magnetic field generated by the core of the MRI.

How to guarantee that power supplies exposed to such extreme conditions will do the job?

From Conrad Roentgen to Raymond Damadian

As long ago as 1895, Conrad Roentgen found that an emitting discharge tube contained in a sealed box and radiating in the direction of a paper plate covered on one side with barium platinocyanide became fluorescent, and even when an object was placed between the tube and the plate a picture was obtained - the first X-ray. Fast forward to 1977 when Raymond Damadian was performing equally groundbreaking experiments with his Nuclear Magnetic Resonance (NMR) body scanner to produce much more detailed images of the inside of a human body. In both cases the images obtained have contributed greatly to improve medical diagnostics, the quality of treatment and peoples' lives.

From the original X-Ray equipment and the Damadian NMR to the latest MRI technology offering extremely high-resolution imagery, all share a common need for a large variety of power supplies delivering from a few watts to multiple kilowatts. As the level of imaging resolution has improved, MRI manufacturers are designing new equipment placed very close to intense magnetic fields, requiring very stable power that does not interfere with the data acquisition process.

Operating a switching power supply in very high magnetic field environments is very challenging and even reaches certain technical and physical limits as we know them today. To surpass these limits, power designers are exploring new paths, combining state of the art power conversion topologies with advanced software and digital technologies.

This is a very interesting area for power designers to explore, but before revealing the magic power solution, let us understand how MRI works and what challenges face power designers in such extreme environments.

From discovery to practice

Figure 01 - 1974 Damadian patent

X-Ray equipment has contributed to impressive medical progress, but the resultant images are limited to identifying solids, and exposure to radiation is dangerous for both patients and operators. These drawbacks provided the original motivation for the physician and scientist Dr. Raymond Damadian to explore a new way to scan the human body by researching the properties and behavior of an atomic nuclei when exposed to a magnetic field. After more than 10 years of research and a mix of successes and failure, in March 1972 he applied for a patent for an "Apparatus and method for detecting cancer in tissue" which USPTO granted in February 1974 (US3789832) (Figure 01).  "An apparatus and method in which a tissue sample is positioned in a nuclear induction apparatus whereby selected nuclei are energized from their equilibrium states to higher energy states through nuclear magnetic resonance. By measuring the spin-lattice relaxation time and the spin-spin relaxation time as the energized nuclei return to their equilibrium states, and then comparing these relaxation times with their respective values for known normal and malignant tissue, an indication of the presence and degree of malignancy of cancerous tissue can be obtained."

When Nikola Tesla revealed the evidence of the rotating magnetic field in 1882, he could hardly have imagined that 90 years later it would lead to Dr. Raymond Damadian using a magnetic field to see inside bodies! And for sure, no one could have imagined the level of resolution that modern MRIs have achieved.

Let's look at how an MRI works and how power supply designers have invented new power solutions able to operate in multi tesla environments.

Hydrogen nuclei are the key in MRI!

As we learned in school, the human body is composed of 70% water. Water molecules are made up of two hydrogen atoms and one oxygen atom (H2O). An MRI machine can identify hydrogen nuclei contained in water molecules, which have a quantum physics property called spin. We can compare the Hydrogen proton to the planet earth rotating on its axis, with a north and a south pole. Under normal circumstances, these hydrogen proton bar-magnets spin in the body with their axes randomly aligned (Figure 02.1).

Figure 02 - Hydrogen nuclei polarization during the MRI activation phases

When the patient's body is placed in a strong magnetic field the protons' axes all line up. This uniform alignment creates a magnetic vector oriented along the axis of the scanner (Figure 02.2). Depending on the object under observation, the MRI scanners have different field strengths, usually between 0.5 and 3 tesla (T) (note that the gauss unit is often used as well: 1 tesla = 10.000 gauss). The latest generation of MRI reach six tesla, thus Neurospin brain research is using 11.7 T, which is 234.000 times the Earth's field, and in the case of spectroscopy even up to 20 T. The main magnetic field is referenced as vertical or B0  (B zero).

When additional energy in the form of a radio wave is added to the magnetic field (B0), the magnetic vector is deflected. The radio wave frequency that causes the hydrogen nuclei to resonate is dependent on the element sought and the strength of the magnetic field (Figure 02.3). Two magnetics fields are used, the Gradient (B1) and the RF field.

Figure 03 – Brain high resolution picture obtain after data acquisition

Multiple transmitted radio frequency pulses can be used in sequence to emphasize particular tissues or abnormalities. A different emphasis occurs because different tissues relax at different rates when the transmitted radio frequency pulse is switched off.

This simple description highlights the level of the strong magnetic fields involved in the hostile environment of MRI applications, which power supplies designers must take into consideration when developing products for such demanding applications.

Forces in power

To understand what power designers have to consider, it is important to understand the magnetic and electromagnetic forces involved with an MRI scanner and how they can interact with the power supply, which can also interact with the sensitive data collected by the different sensors (Figure 04).

Figure 04 – Simplified representation of an MRI equipment and the different fields contributing to create the final image

Gradient fields (B1)
B1 is generated by a specific combination of coils in the three axis X, Y and Z. The pulsed frequencies are around 100 KHz with intensity as low as few mT/m. The frequency is adjusted to suit the object being examined and the frequency can be modulated.

RF field
The RF field is generated by a separate coil in the X and Y-axis. The frequency range is comprised between 64 MHz and 299 MHz with micro-tesla intensities.

How to provide power in such environments?

To avoid interference, the best practice in powering MRI is to avoid alternative voltage/current (AC) and to only use continuous voltage/current (DC), even for lighting. Master power supplies are traditionally positioned outside the shielded operation room and the DC voltage is distributed to the electronic equipment via shielded cables.

To adjust the voltage from the main DC line to a specific load (e.g. 24 VDC to 12 VDC), the old generation of MRI equipment used a large variety of linear step-down voltage regulators, which reduced the risk of disturbances, but inherent to their technology is a very low energy efficiency and high power dissipation. Requiring more power and better energy utilization, new generations of equipment have adopted switching power regulators, which have improved power efficiency but have also became a source of potential disturbances! When the power supply is far enough from B0 and sensitive equipment, efficient shielding and grounding can prevent interference, but when the power supply is located close or even within B0, then power designers are facing real challenges.
 
MRI impact on the power supply

Master magnetic field (B0)
A switching power supply transforms a DC voltage into an AC one, and then rectifies it to DC. During the conversion process the transferred energy is stored in a transformer composed of a coil(s) and a core, usually made of ferrite. The high density of B0 interacts directly with all ferromagnetic components, saturating iron-cores and making it impossible to transfer the energy and even becoming a short circuit.

Gradient fields (B1)
The gradient field frequency is very much the same as the average switching frequency of conventional power supplies but induces a 'current storm effect' in cables and conductive areas. This also affects the switching performance of the power stage resulting in signal distortion, heat and in most of the case short circuit of the switching components.

RF field
Due to its much higher frequency, the RF field is less harmful for the power supply though induced currents could result in the form of similar collateral defects as generated by the B1 field.

Power supply impact on MRI

Master magnetic field (B0)
Even though the Larmor frequency is 42.58 MHz/Tesla for protons (hydrogen nuclei), there is a risk that the power supply switching spikes can impact the signal with the consequence of generating artifacts that affect image quality and resolution.

Gradient fields (B1)
Because the switching frequency of a standard power supply is in the same range (100 KHz) of the gradient filed, that could interfere with the signal generated by the gradient loop, and as a consequence modify the encoded signal, resulting in image artifacts.

RF field
In the case of RF, the harmonics of the fundamental switching power supply could interfere with the RF coil loop causing alteration of the MRI RF signal and a negative effect on image quality.

How to make a power supply that works?

Taking into consideration the different parameters, it is obvious that a suitable power solution will have to exclude ferromagnetic components and its switching frequency must not interfere with the MRI signals.

Because conventional magnetic cores will saturate when exposed to the B0 field energy, air-core inductors, having no ferromagnetic core material, should be considered. One downside of air-cored inductors is their low inductance values, which can be compensated by designing a multi air-cored power stage operating in parallel. Controlling multi-parallel air-cored power supplies requires the implementation of the latest digital control technology, offering a high degree of flexibility in how the different power channels operate. Digital control allows designers to adapt the profile of the power supply to specific conditions.

Figure 05a shows an example of an advanced air-core power supply, the PRBX GB350. To accommodate the specific MRI, B0, B1 and RF specifications that it has been designed for, the GB350 has a fundamental switching frequency of 600kHz. With such a switching frequency and its four-phase interleave mode, the GB350 has a resultant output frequency of 2.4MHz. This allows easier filtering and extremely fast regulation response times. The unit also includes EMI shielding to lower radiated emission and prevent any risk of artifacts (Figure 05b).

Figure 05a – Triple outputs, multi-phases, PRBX coreless power supply sustaining B0 field

Figure 05b – PRBX coreless power supply sustaining B0 field shielded to protect against interferences

In conclusion

Figure 06 – MRI equipment with advanced data acquisition requires very stable power supplies able to operate in high magnetic field (Source: iStock / baranozdemir / PRBX)

In less than 50 years, the progress of the Magnetic Resonance Imaging (MRI) scanner has been impressive and image resolution quality, astonishing (Figure 06). By permanently innovating, the power supply industry has contributed to delivering efficient, sustainable and safe power to very demanding applications such as B0 field conditions. Ultra-high field strength systems with a new generation of sensors will require extremely fast response power sources switching at 25 MHz to avoid harmonics in the safety band and I can foresee a new generation of coreless power supplies combining air-core, digital control and the use of Gallium Nitride (GaN) transistors.

There is no doubt, power designers developing power solutions for medical imagery systems will continue to make magic a reality!

References:

• US patent 3,789,832 - Feb. 5, 1974 – Damadian – Apparatus and method for detecting cancer in tissue
• Anne Perrin and M. Souques (eds.), Electromagnetic Fields, Environment and Health, DOI: 10.1007/978-2-8178-0363-0_2
• Robert R. Edelman - The History of MR Imaging as Seen through the Pages of Radiology - Radiology: Volume 273: Number 2 (Supplement)—November 2014

Provided by Patrick LeFévre Chief Marketing and Communications Officer, Powerbox

If you or anyone in your company is interested in getting on the distribution list for future issues of PSMA UPDATE, please send e-mail to: power@psma.com. Be sure to include your name and the name of your company.