publisher’s note - power systems design · 2013. 10. 16. · 4 contents publisher’s note two...
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www.powersystemsdesign.com 4
CONTENTS
Publisher’s NoteTwo Years Young and Stronger than Ever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Industry NewsON Semi Named Jean Marie Doutrewe Director . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Zetex Named Hans Rohrer CEO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Silica Wins Demand Creation Award . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
STMicro Among Top Ten Green Companies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
National Power Design Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Maxwell Expands Distributor Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
National Semiconductor Introduces Industry’s First Single-Chip, Power over the Ethernet Device Controller Designed for
Low-Voltage Auxiliary Power Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Striving for the Universal Power Management Solution, Davin Lee, Intersil Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
MarketwatchWant a Bigger, Greener Power Market? Learn to Lobby, Chris Ambarian, iSuppli Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Cover StoryPursuing the Power Paradox, Peter Vaughn, Power Integrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
FeaturesIGBT Modules—HiPak Modules with Next Generation SPT+ IGBTs, Eric Carroll and Munaf Rahimo, ABB Switzerland Ltd,
Semiconductors, Switzerland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Power Management—Intelligent Hot Swap Control, Chris Umminger and Todd Nelson, Linear Technologies . . . . . . . . . . . . .27
Power Measurement—Advanced Precision Power Analyser, Iwase Hisashi, Itou Osamu and Tachibana Katsuya, Yokogawa . . .32
Power Amplifiers—Power Amplifiers Proof-Test Equipment, Helmut K. Rohrer, Rohrer GmbH, Munich . . . . . . . . . . . . . . . . . . .37
Power Generation—Mobile Electrical Generator Sets, Jan Leuchter and Otakar Kurka, University of Defense (Czech Republic)
Pavol Bauer, Delft University of Technology (The Netherlands) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Power Modules—Integration of Power Devices, Toru Araki, Mitsubishi Electric Corporation and
Robert Wiatr, Mitsubishi Electric Europe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
New Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49-52
Member Representing
Eric Carroll ABB SwitzerlandArnold Alderman AnagenesisHeinz Rüedi CT-Concept TechnologyClaus Petersen DanfossDr. Reinhold Bayerer eupecChris Rexer Fairchild SemiconductorDr. Leo Lorenz Infineon TechnologiesDavin Lee Intersil Eric Lidow International RectifierDavid Bell Linear Technology
Member Representing
Rüdiger Bürkel LEM ComponentsRalf J. Muenster MicrelPaul Greenland National SemiconductorKirk Schwiebert OhmiteChristophe Basso On SemiconductorBalu Balakrishnan Power IntegrationsDr. Thomas Stockmeier SemikronUwe Mengelkamp Texas InstrumentsPeter Sontheimer Tyco Electronics
Power Systems Design Europe Steering Committee Members
PowerSystems DesignE U R O P EPowerSystems DesignE U R O P E
2 Power Systems Design Europe January/February 2006
This issue marks the beginning of PowerSystems Design Europe’s third year in publishing.
We are very pleased with the success ourpublication has achieved and the support wehave received from our industry partners,friends, families and loyal readers.
2005 was a banner year for Power SystemsDesign Europe as within our ten issues; wepublished a total of 584 pages of content direct-ed at the design and applications needs ofEuropean engineering professionals dealingwith power electronics, power managementand intelligent motion control.
As you are acutely aware, power hasbecome a major issue in all product designspanning all sectors of the electronics industryand across all regions of the world. PowerSystems Design Europe is solidly entrenchedas the number one trade journal servingEurope’s power electronics community.
We are firmly committed to lead the trends inpower electronics, not follow them. To this endwe have made several proactive enhancementsto our publishing efforts. Specifically we haveexpanded our publishing efforts into China withthe launch of Power Systems Design China,both in print and online during 2005. Under thedirection of our Editor-in-Chief Liu Hong, [email protected], we will publish PowerSystems Design China six times during 2006.Additionally, with Liu Hong working from ourBeijing office, we now have a direct line to edi-torial from China’s power electronics engi-neering community.
Our next geographic move, which takesplace this month, is the Launch of PowerSystems Design North America in an onlineformat only, which will publish 10 times a yearand be distributed to 32,000 power electronicengineering professionals.
On the editorial side, we have made sever-al enhancements since we launched PowerSystems Design Europe in February 2004.Specifically we established an “EditorialSteering Committee” to insure that we are edi-torially leading the community and have addedfive new columns which enable us to give youa broader peek into global power electronicsindustry. These departments are:
1. PowerLine—A feature product announce-ment column for significant new productslaunches.
2. PowerPlayer—Contributed each issue byone of our esteemed “Editorial SteeringCommittee” members. This is a platform forthem to speak their mind about the powerelectronics industry. This is a no-holds-barredcolumn on the topic of their choice.
3. TechTalk—A column which will debut in ourMarch 2006 issue, TechTalk is a forum tointerview senior level executives in the powerelectronics community about technical issuesof significance.
4. MarketWatch—Contributed by Chris Ambarian,Senior Power Analyst for iSuppli Corporation.MarketWatch gives you a peak into the inter-nal workings of our industry and what thefuture might bring.
5. Focus Series—Where we focus our editorialin that specific issue on a significant seg-ment of power electronics, such asAutomotive, industrial and portable power.
In case it is not painfully obvious; we are allabout power, and support global power asso-ciations and events. Specifically, we are a mem-ber of PSMA (Power Sources ManufacturersAssociation) and “Official Media Partners” forPCIM Europe 2006—Nuremberg, Germany;PCIM China 2006—Shanghai, China andAPEC 2006—Dallas, Texas USA.
If your travels take you to one or more ofthese events, please stop by our stand andsay hello. Please see page 6 of this issue fordates and details.
Cheers!
Jim
Jim GrahamPublishing DirectorPower Systems [email protected]
AGS Media Group
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Editor-in-Chief Power Systems Design China Liu [email protected]
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Registration of copyright: January 2004
ISSN number: 1613-6365
Issue print run: 20,000
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Volume 3, Issue 1
PUBLISHER’S NOTE
Two Years Young andStronger than Ever
4 Power Systems Design Europe January/February 2006
INDUSTRY NEWS
ON Semi Named Jean Marie Doutrewe Director
ON Semiconductor announced the appoint-ment of Jean Marie Doutrewe as director of
Sales, Marketing and Services operations inEurope, the Middle East and Africa (EMEA).Mr. Doutrewe takes over the responsibilitiesheld by Sergio Levi, vice president of EMEAsales. Mr. Levi decided to leave the companyat the end of 2005.
Mr. Doutrewe brings a wealth of semicon-ductor industry experience to the position,having held leadership roles in planning,logistics, customer service, distribution, andOEM sales. Most recently, he held the posi-tion of Director of ON Semiconductor’s serv-ice operations in EMEA, and site manager ofPiestany, Slovakia. In 2002—when the com-pany decided to relocate its European andNorth American customer service operationsto Piestany—Mr. Doutrewe led the centraliza-tion efforts.
Prior to ON Semiconductor’s spin-off fromMotorola, Mr. Doutrewe worked for Motorola’sEMEA sales organization. Joining Motorola in
1987, he headed up the discrete productgroup planning team in Toulouse, France.During his career, Mr. Doutrewe has alsoworked as Business Director for GeneralElectric’s south Europe semiconductor divi-sion and held several management positionswith RCA in Europe.
In this new role at ON Semiconductor, Mr. Doutrewe will dual report to Bill Bradford,senior vice president of the company’s globalSales and Marketing, and to CharlotteDiener, vice president and general managerof Global Supply Chain Management.
www.onsemi.com
Europe Sales Offices: France 33-1-41079555 Italy 39-02-38093656 Germany 49-89-9624550 Sweden 46-8-623-1600 UK 44-1628-477066 Finland 358-9-88733699 Distributors:Belgium ACAL 32-0-2-7205983 Finland Tech Data 358-9-88733382 France Arrow Electronique 33-1-49-784978, TekelecAirtronic 33-1-56302425 Germany Insight 49-89-611080,
Setron 49-531-80980 Ireland MEMEC 353-61-411842 Israel AvnetComponents 972-9-778-0351 Italy Silverstar 39-02-66125-1Netherlands ACAL 31-0-402502602 Spain Arrow 34-91-304-3040Turkey Arrow Elektronik 90-216-4645090 UK Arrow Electronics 44-1234-791719, Insight Memec 44-1296-330061
The Board of Zetex plc announces theappointment of Hans Rohrer as ChiefExecutive Officer to take over from Bob
Conway who has decided to retire from the business.
Hans Rohrer brings a wealth of experienceand a proven track record in the semiconduc-tor industry to Zetex. Hans began his careerin R&D at Diehl Data Systems before movingon to Texas Instruments where he held engi-neering and marketing positions. He hasworked for the bulk of his career (1980-1998)at National Semiconductor. During his seven-teen year tenure at National Semiconductor,Hans held several management positionsamongst them vice president and generalmanager Europe and vice president for VLSI/mixed signal products. Under his seven yearleadership as vice president and generalmanager, National Semiconductor Europe’srevenues grew to well above a quarter of itsworldwide revenues – the highest of anymajor US semiconductor company- and wasranked among the top three suppliers by allof its major customers.
Hans then became President of TSMC-Europe, the world’s largest independentsemiconductor wafer foundry where, in addi-tion to being responsible for the day to dayoperations, he was instrumental in bringingabout a far–reaching technological develop-ment project between TSMC, Philips and ST Microelectronics. Latterly he has beenCEO of Acuid, a venture backed technologybusiness specialising in semiconductor solu-tions for automated test equipment. Hansholds a master’s degree in electronics andreceived business and management educa-tion from Stanford University, California andINSEAD, Paris.
Hans joined Zetex on 30th of December2005, and will join the Board on February 1st 2006.
Zetex Named Hans Rohrer CEO
www.zetex.com
Silica, an Avnet company, won the EuropeanDemand Creation award for being the clearleader with the highest number of new designopportunities within the first half of 2005. Theaward reflects the importance that Freescaleplaces on the distribution channel in supportingdemand creation growth.
“The success has been due to the way weinteract with the customer, every project hasvery individual demands and it is essential thatall aspects of the project are considered beforedesigning in a product,” said Miguel Fernandez,President of Silica. “We put great emphasis onsupporting customers with application based
design-in support and thereby create greaterdemand for products.”
Silica markets the entire Freescale productrange and supports customers with in-depthtechnical workshops on a European base.
Silica Wins Demand Creation Award
www.silica.com
6
INDUSTRY NEWS
Power Events
• EMV 2006, March 7-9, Düsseldorf www.mesago.de
• ECPE 2006 SiC User Forum, March 14-16,Nuremberg, www.ecpe.org/news/news_e.php
• APEC 2006, March, 19 - 23, Dallas TX,www.apec-conf.org
• PCIM China 2006, Mar. 21 - 23, Shanghai www.pcimchina.com
• PCIM Europe 2006, May 30 - June1,Nuremberg, www.pcim.de
• SMT/HYBRID 2006, May 30 - June1, Nuremberg,www.mesago.de
• SENSOR/TEST 2006, May 30 - June1,Nuremberg, www.sensor-test.de
• EPE-PEMC 2006, Aug 30 - Sep 1, Portoroz,Slovenia, www.ro.feri.uni-mb.si/epe-pemc2006
• MICROSYSTEM, October 5 - 6 , Munich,www.mesago.de
• ELECTRONICA 2006, Nov. 14 - 17, Munich,www.electronica.de
• SPS/IPC/DRIVES 2006, Nov. 28 - 30,Nuremberg, www.mesago.de
Maxwell Technologies announced that it hasadded eight new distributors in Europe and theMiddle East to serve growing demand forBOOSTCAP ultracapacitor products and relat-ed technical and customer support. “Thesenew channel partners will help us to ensurethe best service and technical support andfast, local language response for customers intheir respective geographic regions.”
The newly signed BOOSTCAPdistributors are:
• Alfatec – Germany,• Alphatron – Netherlands, Belgium,
Luxembourg and Denmark,• BLL – Israel,• Dimac Red – Italy,• Inelec – Spain,• OEM Components – Sweden, Norway,
Finland and Poland,• Williamson – France• Young ECC – United Kingdom.
BOOSTCAP ultracapacitors are an innova-tive energy storage technology ideally suitedfor applications needing repeated bursts ofpower for fractions of a second to several minutes. Ultracapacitors provide up to 100times the energy of conventional capacitorsand deliver up to 100 times the power of ordinary batteries, require no maintenance,and operate safely and reliably in extremetemperatures.
Maxwell Expands Distributor Network
www.maxwell.com
National Semiconductor will hold a tour ofadvanced technical courses on power man-agement design, starting on February 23rd.Design engineers will receive an in-depthtraining in power supply design and analysisfrom the industry leader in power manage-ment ICs. The course will be presented byexperts from National, with guest speakersfrom Coilcraft and the University of Salerno(Italy). It will cover techniques, topologies
and tools to address real-world designneeds. Design engineers are invited to partic-ipate in free, day-long courses in seven citiesin Europe and Israel.
Each of the 1-day courses will consist offive training segments:
• High current buck switching power supply design
• Forward active clamp design• New power supply solutions
• Practical design considerations• Optimising magnetics selection and
design for power suppliesAll courses are free of charge. Pre-regis-
tration is required to guarantee a place,which includes lunch and presentation hand-book. For detailed information and registration,see www.national.com/see/powercourses
National Power Design Courses
www.national.com
Power Systems Design Europe January/February 2006
Already Successful with its iSim Tool forPSTMicroelectronics has been named at thetop of the Best Management Practices cate-gory and ranked among the Top TenCompanies of the Decade in the inauguralLow Carbon Leader Awards presented byThe Climate Group and published with arecent survey on greenhouse gas emissionsby BusinessWeek, on December 12, 2005.
The Climate Group and BusinessWeekhave recognized and acknowledged ST’sbest-in-class management practices, initiatedby ST’s former CEO, and Honorary ChairmanPasquale Pistorio, and carried on by theCompany’s current CEO, Carlo Bozotti.
Pistorio, who believed environmental initia-tives in making chips should come from thetop, issued ST’s Environmental Decaloguewith measurable, time-defined goals for envi-ronmental performance in 1995. With itsaggressive Carbon Roadmap as a top execu-tive priority, ST has succeeded in reducing itsCO2 emissions by 50% over the past tenyears, targeting carbon neutrality and totalaccumulated energy savings of $900 millionby 2010. Last year alone, the Companysaved $173 million in energy, water, andchemical costs, relative to its 1994 per-unitbenchmarks.
Apart from reducing total emissions of
CO2 by at least 5% per year, ST’s carbonneutrality programs include aggressively trim-ming emissions of perfluorinated compounds,adoption of renewable energy sources, suchas wind and water, and reforestation as ameans of compensating for the remainingCO2 emissions.
The jury has also rated ST’s HonoraryChairman Pasquale Pistorio as one of themost influential individual achievers in thefight against global warming.
STMicro Among Top Ten Green Companies
www.st.com
www.powersystemsdesign.com 9
formance error amplifier for non-isolatedapplications.
Compelling features and benefitsNational's LM5071 has a number of
unique characteristics that make it easyto design in:
• Auxiliary power interface: Accepts awide range of auxiliary power sourcevoltages (12V to 48V) and activatesthe DC-DC converter to efficientlysupply the various loads of the PD.
• UVLO threshold and hysteresis:Designers can program the under-voltage lockout (UVLO) trip-pointand hysteresis completely independ-ently. This allows precise control ofstart-up line currents and the startand stop voltage points as desired ina variety of system applications.
• Controls isolated or non-isolatedDC-DC converters: Integrates theprecision voltage reference and erroramplifier for DC-DC feedback innon-isolated converters, including
the simple Buck topology. Providesinternal pull-up for opto-coupler tran-sistor in isolated designs.
• Signature resistor disconnect: The25 kiloOhm signature resistor is disconnected after PD detection toreduce power loss.
• Programmable oscillator frequency:The oscillator for the switching regu-lator controller is fully programma-ble, allowing the user to optimiseregulator performance.
• 50 percent or 80 percent maximumduty cycle: Available with either 50percent or 80 percent maximumPWM duty cycle to support a varietyof DC-DC converter topologies andpermit operation over an extendedinput voltage range.
8 Power Systems Design Europe January/February 2006
Billed as the industry's first single-chip solution specifically designedfor Power over Ethernet (PoE)
devices that operate from alternativepower sources or the PoE-enabled network. The LM5071 is a PoweredDevice (PD) interface and DC-DC con-verter IC that simplifies the design of avariety of PoE applications that requirean auxiliary power source such as anAC adapter.
Devices powered by a PoE networkinclude IP phones, security camerasand wireless local area network (WLAN)nodes connected through Ethernet net-working cables and ports. Operatingthese PoE devices from alternate power sources is often necessary torelieve the burden on the PowerSourcing Equipment (PSE) or to operatethe device on a network that is not
PoE-enabled. Current solutions limit the choice of auxiliary power sources,which can drive up overall system costor complexity.
National's LM5071 is the industry'sfirst single-chip, IEEE 802.3af-compliantPD interface port and pulse-width modulator (PWM) controller specificallydesigned to accept power from externalAC adapters. The LM5071 integrates aPD front end that accepts power fromthe PSE or auxiliary power to a singlechip with a DC-DC controller that stepsdown the input voltage to power variousPD loads.
Powering the device from an ACadapter can be tricky and requires fore-thought by the IC designer. The LM5071solves the auxiliary power interfaceproblem encountered by many PoE
equipment designers with an elegant,integrated PD solution. This new addi-tion to National's PoE power productfamily accepts a wide range of ACadapter voltages, giving equipmentdesigners the flexibility to optimise total system cost.
Key technical specificationsThe LM5071 is fabricated with
National's ABCD150-XV1 high-voltageanalogue bipolar/CMOS/DMOS technol-ogy and offers advantages such as anintegrated, high-frequency, current-mode DC-DC controller, user-program-mable under-voltage threshold and hysteresis, and a highly accurate faultcurrent control loop. It features a maxi-mum input voltage of 80V, user-pro-grammable oscillator frequency up to 1MHz and over-temperature protection,plus a voltage reference and high-per-
ILM5071 offers designers better flexibilityto operate PoE powered devices from
AC adapters as low as 9.5V orfrom the power sourcing equipment
http://power.national.com
10 Power Systems Design Europe January/February 2006
In today’s ever changing world of hard-ware technology, the one thing thatremains constant is the need for more
sophisticated power management. Drivenby power hungry processors, FPGAsand other semiconductors, today’spower management solutions deliverincreased power, greater efficiency, programmability and higher integrationwhile residing in smaller packages.
These advances in power manage-ment did not take place overnight. It has taken greater than 20 years to getto this point. Evolution, not revolution,has defined the progression of powermanagement in the semiconductorspace since its inception.
Just a few years back, linear regula-tors were the choice of many board leveldesigners as they were simple to use andrequired little to no power design expert-ise. This combined with the low cost oflinear solutions made them the voltageregulator of choice. Switching regulatorswere relegated to higher output loadswhich require higher efficiency.
Today, switching regulators are preva-lent due to numerous factors. First, betterpower dissipation results in the elimina-tion of special power packages and heatsinks, thereby reducing the complexityand cost. Second, power budget man-agement has become extremely impor-tant to system designers and, as a result,efficiency has become the main factor inselecting the optimal power solutions.This is the area in which switching regu-lators excel, particularly when higherloads are required. Third, the cost ofswitching regulators has decreased overthe past few years as better processtechnologies have allowed higher inte-gration and resulted in smaller die sizes.Many of today’s switching regulatorshave PWM controllers, FET drivers andthe power FET(s) integrated into a single
package. Fourth, higher integration hasallowed higher switching frequencies,leading to smaller size of external induc-tors and capacitors and consequently asmaller footprint. Fifth is the increase inthe “ease of use” factor. With internally-compensated regulators, a designer isno longer required to perform tediouscomplex calculations to determine theoptimal external components to achievean efficient and stable control loop.Today, he or she can simply select theinput and output capacitors and outputinductor from a table based on a set ofparameters. With this simplification inimplementing switching regulators, theaverage designer can now take advan-tage of the higher efficiencies achievedwith switching regulators to minimizeheat dissipation and maximize powerbudgets. Better heat dissipation, higherefficiency, reduced cost, higher integra-tion, higher switching frequency andconsequently smaller footprint, as wellas ease of use have made switchingregulators an attractive alternative to linear regulators. There remain certaincases in which linear regulators are stillthe optimal choice, but switching regula-tors are now the preferred solutionamong system designers.
Another evolution in power regulationis the adoption of wide input voltage (Vin)multiple output power solutions withhighly programmable features. Today,more and more systems are requiringnumerous voltage rails to support thevarious semiconductors that reside onthe board. Multiple output power solu-tions have risen to address this demand.Products such as the ISL6442 containtwo PWM controllers and a linear con-troller in one package with a wide Vinrange of 4.5V to 24V. The switching frequency is programmable from 600kHz to 2.5MHz to allow usage of smalleroutput inductors with all three outputsbeing programmable.
With the advent of digital power, weare one step closer to arriving at a uni-versal programmable switching regulator.Although digital control loops remainunproven in the mass market, they areon the verge of delivering the stable per-formance found previously in analogcontrol loops in addition to providingaccess to programmable parametersdigitally. By utilizing a digital interfacesuch as PMBus, a power designer canquickly and easily modify the digitalpower integrated circuit’s digital coeffi-cients to adjust and fine tune parametersrelated to loop compensation, advancedfault protection and monitoring, sequenc-ing and startup, thereby increasing per-formance of the regulator and increasingprotection and reliability. Software GUI-based tools make the task of digital pro-gramming easy and accessible to powerdesigners. Before digital power, this flex-ibility and control was only accessible toa chip designer during the design stageor to those exceptional power engineersthat fully understand external compen-sation schemes.
www.intersil.com
By Davin Lee, VP, General Purpose Power, Intersil Corporation
www.powersystemsdesign.com 1312
By Chris Ambarian, Senior Analyst, iSuppli Corporation
There is a certain soundness to thelogic proposed by several folks inthe industry that says that if you
make green-ness and power efficiencycost-neutral to the customer, then themarket for those efficient products willexpand rapidly. Sounds reasonableenough on the face of it. But today I’mgoing to question both the premise andthe implication in this assertion. I wouldlike to suggest that this thinking over-simplifies and/or misjudges the marketin two dimensions—both the supplierside and the customer side—and indoing so we unnecessarily reduce theadoption of higher efficiency electronicequipment. This has the doubly negativeeffect of both unrealized revenues for sup-pliers, and the prolonged use in the worldof low-efficiency electric equipment.
First, let’s ask ourselves a leadingquestion. Why do we even have theoccasion to be talking about ways toexpand the high-efficiency power elec-tronic equipment market? I would sug-gest that the reason is that we intuitivelyknow that efficient electronic replace-ments for traditional electric equipmentare already cost effective, and that mar-ket adoption of these technologies couldbe much, much higher. But if efficiencyis already cost effective and marketadoption is low, then there must bemore to the story. To just pursue costeffectiveness may overlook some otherinertia, purchase barrier, or irrationalityon the part of the consumer.
In my own examinations of the marketsuccess of high-efficiency power technolo-gies in various applications, my findingsare that there is a non-exclusive priorityranking of four key factors that driveadoption rates. To jump right to the con-clusion of this discussion, that ranking is:
1. Legislative mandates for efficiency2. Cost of energy3. Elimination of cost barriers to purchase4. Voluntary efficiency guidelines
Now to flesh out our discussion andjustify this list, let’s take a look at each,from the bottom up.
Voluntary guidelinesHere we have things like EnergyStar
from the US Environmental ProtectionAgency (EPA). This is a non-legislatedguideline, designed to help policy mak-ers more easily make or encourage cer-tain buying decisions. The great thingabout them is that such guidelines aresimple; they can be created relativelyquickly and, with the proper bit of net-working and private lobbying, retailerscan be pressured into pressuring theirsuppliers (and their suppliers in turn) tocomply with the guideline. The downsideis that in searching for somethingachievable without having any authoritywhatsoever, compromises must bemade and the guidelines very rarelypush efficiency to levels that are at alltechnically challenging—essentially,they are a lowest common denominatorefficiency approach.
In summary: consumers get non-aggressive efficiencies; adoption ratelimited to that mandated by retailers.Thus far, that’s probably 40% of themarket, max. Market examples: 1) The PC market. Monitors areEnergyStar compliant. Peripherals areoften not. Power adapters are mostoften not. 2) The Kyoto Protocol. Voluntary,and yet fleet fuel-efficiencies have actu-ally decreased since its adoption byover 100 countries.
Eliminated initial cost barrierI worded it this way because I think
this is a more universal phrase that cov-ers not only cost reduction, but actuallyany means by which we can mitigate apotential consumer’s reaction of “I wouldlike to buy it, but I won’t pay that muchextra for it.” Thus, if you lower the priceof that super-efficient water heater downto the same price as that cheap, inefficientone, yeah, I’ll buy it. OR, if the energyutility company will give me an incentivepayment that makes the price differen-tial almost nothing, I’ll also buy it. Why?Because you eliminated my cost barrier!
In summary: Consumers get as muchefficiency as you’ll provide them for thesame immediate or initial cost. Marketadoption is limited only by how manypeople have access to the lowered bar-rier, as well as by replacement life cycleand customer inertia (or laziness). Notethat the customer needs to have no bar-rier at the time that they go in to pur-chase—which in the case of refrigera-tors or air conditioners may be areplacement cycle time of 5 to 20 years.The subtleties and interactions betweencost, efficiency, government policy, andmarket development can be the subjectof an entire paper; suffice to say fortoday that in fact, lowering the price tothe customer of an efficient solution to
MARKETWATCH
Power Systems Design Europe January/February 2006
the point where it’s cheaper than aninefficient solution is a great, consistentway to effect market adoption—but it’snot always possible to do. That fact thatit may not be possible for a particularproduct does not necessarily invalidatethe overall cost savings of that prod-uct—it simply may mean that otherways of eliminating the initial-cost barri-er should be considered. And note thateven if this barrier is reduced or elimi-nated, total conversion of the market isnot ensured. Example: rebates fromelectric utilities given for purchases ofmore-efficient models of refrigerators orfluorescent lights.
Cost of energy I took a look at the cost of electricity
in countries around the world for theseveral years period leading up to 2002.Most of the world has been paying afairly stable price for electricity for thelast decade, at prices that fall into 3main groups, as shown in Figure 1.Group 1 is Japan and Denmark at overUS $0.20/kWh; Group 2 is Most ofEurope, at US $0.12-.15/kWh, andGroup 3 is the Rest of the IndustrialWorld, at roughly US $0.07-.09/kWh.
I noticed a striking correlationbetween this graph and the penetration
of high-duty cycle fractional motordrives: The higher the cost of electricity,the higher the penetration rate of elec-tronic controls on motor drives. Formotors with a high duty cycle (i.e., appli-ances that spend a high percentage oftheir time on), the correlation is remark-able. There is a strong correlationbetween the cost of electricity and theratio of motor drive penetration. In mar-kets where the cost of electricity is high,there is a very high rate of adoption ofmotor controls. In Japan, virtually 100%of air conditioners have inverter drives,while China, the world’s largest produc-er, uses inverters on less than 10% oftheir production. Similarly, Chinaemploys inverters on less than 1% ofrefrigerators, the US about 5%. 9% ofChinese washing machines have invert-ers, versus 17% in the US, versus 30%in Europe. In Europe (very obviously inDenmark), a consumer chooses anappliance on the basis of how “green” itis (class A, class B, class C), while inthe US, there is merely “efficient” (whichis not very efficient at all by electronicstandards), and non-efficient.
Could it be that consumers aren’t sodumb? Yes.
In summary: Consumers get as muchefficiency as they can afford—a decisiondriven by the cost of energy. Marketadoption is paced over time by the costof energy, and the amount of savingsthat the efficient technology optionoffers. Example: hybrid electric vehicles.The price of fuel goes up, and peoplebegin doing the calculations. (HEVs alsodemonstrate that consumers can evenbe counted upon to do rather complex,application-specific calculations to eval-uate different types of equipment!)
Legislative mandate Finally, what if the consumer no
longer gets the option of using an out-dated (but cheap) inefficient technolo-gy? We bristle to even think that our“freedom” of choice may be removed –but just for a minute, let’s think about it.Imagine we no longer have a choice; asof today, we have to buy an appliancethat costs $50 more. Will we simply notbuy? No, we need to wash our clothes,
MARKETWATCH
Figure 1. Average worldwide cost per kWh of residential electricity, by country, 1992-2002. The cost for industrial usage is roughly 50-60% of these amounts in every market. (Source: US Energy Information Administration, iSuppli)
www.powersystemsdesign.com 1514 Power Systems Design Europe January/February 2006
or to stay cool in the summer, or to keepour food cold. So we buy… and then wesave $25 or $50 per year in energycosts. The appliance lasts 10 years—sowe have 8 years with an extra $25 to$50 to spend elsewhere in the economy—not to mention that we lowered ourenergy use and its impact on our envi-ronment. And as an added benefit, theappliance is functionally more sophisti-cated! So what is the problem?
The challenge here is really the sameas it is with any legislative activity: groupsfrom both sides of an issue lobbying forlegislation that will serve their interests.In general, we have in the past been ableto count on someone among our govern-ment representatives to propose excel-lent laws—and, we have not been ableto count on the entire body of represen-tatives to ratify those proposals. Rati-fication is generally determined by theside that does the most effective lobbying.
As an example of the challenges, inthe USA a few years ago we passedlaws requiring greater efficiency in homecentral air conditioning units. This was asuperb opportunity for a market expan-sion for electronic motor speed controls.Instead, what got passed was weakerlegislation that measured system effi-ciency at 2 fixed operating points, ratherthan across a range of values you mightsee in real world operation. It was a sim-ple business for manufacturers to avoidusing a variable speed drive by using acheap start capacitor and relay and byoptimizing for those 2 set operatingpoints—even though that optimizationdidn’t substantially increase efficiency at
all in normal use, the way an electronicspeed control would have. (The goodnews is that with subsequently passedregulations going into effect this year,virtually the only way to meet the efficien-cy ratings is to use an electronic control).
On the other hand, by requiring allnew homes to be outfitted with a mini-mum number of compact fluorescentlamps, governments significantly drovethe adoption of electronic ballasts.There was intense lobbying by buildersto not have to invest the extra $15 perhome—but once the regulations werepassed, the builders went whimperingaway, and just complied. No one suffered.
In summary: Consumers all must buythe efficient solution (at least as efficientas is mandated), and market adoption ispaced only by how quickly the laws takeeffect, and on how quickly consumershave to replace their existing solutions.Example: electronic ballast fluorescentlighting legislation in California thatrequired all new buildings to be outfittedwith a minimum number of electronicfluorescent lamps. Becoming effective inthe late 90s, virtually 100% of new build-ings began containing compact electron-ic fluorescent lighting almost overnight.
So what are the strategic implicationsof this multi-faceted model of consumeradoption of green technology?
First, it strikes me that in countrieswhere the cost of energy (be it electricityor petrol) is high, the job of suppliers ofhigh-efficiency equipment is as simpleas making the potential customer aware
of the savings available. Consumers willfigure out what to do—though it maytake some years, and the conversionwill be less than complete (there arealways those who can afford to buy thefuel for a Hummer).
In countries where the cost of energyis low, the challenge is more complex.Low cost of energy has a nearly 1.0 cor-relation with consumer indifference toefficiency (examples being the USA,China, and Russia). The good newshere (at least for semiconductor andelectronic equipment manufacturers) isthat the cost of both electricity and ofpetroleum products has risen sharplysince 2002, taking them above the his-torically constant prices they were at formany years, and this should accelerategrowth without any further action on ourpart. But still, even with higher energycosts, those costs are still not in linewith those in the middle-tier countries inEurope where after many years there isstill a significant portion of the marketyet to be converted to electronic solutions.
In those applications and especially in those geographies with low adoptionrates, the market can still be aggres-sively grown by a combination of tacticsthat play on the other market drivers inthe list.
The easiest (but lowest impact) actionis to encourage voluntary guidelines.Such actions are already taking place,with various organizations working tocreate standards and encourage theiradoption. From our standpoint in theindustry, this doesn’t really require much
of us except to help provide efficiencydata to those organizations to assistthem in crafting their messages.
But the real terra incognita for thepower management industry is tobecome heavily involved 1) in the publicpolicy side of the elimination of the initialcost barrier, and 2) even in the draftingof laws that would require high-efficien-cy electronic solutions in all those appli-cations that would provide the consumerenough benefit to result in a net returnon their extra investment.
On the issue of the initial cost, oneway to do this is to just make the moreefficient approach cost the same or less,as some suggest. The other is toencourage governments and/or publicutilities to subsidize the consumer’s ini-tial investment in highly efficient tech-nologies to the point that the subsidyovercomes the consumer’s hesitation.The subsidies can end when costscome down to a point of parity, or whenmainstream consumers realize that infact the higher efficiency technology isthe way to go.
The second area even more unchart-ed for suppliers in general would be toactively lobby for mandatory require-ments for compliance with aggressivebut achievable efficiencies. This is notsuch a farfetched notion: in the face ofthe failure of consumers and suppliersalike to adhere to the targets set by the(voluntary) Kyoto Protocol, the EU isalready strongly considering mandatorycompliance for fleet-average fuel effi-ciencies that will effectively require asignificant percentage of passengervehicles to be hybrid electrics. Californiahas done the same. And both of these,when enforced, will be a big boon thepower semiconductor industry.
Admittedly, the analysis above ismulti-faceted, and probably beyondwhat’s marketable to a consumer—butthe consumer never has to see this.These suggestions are certainly not toocomplex for suppliers to just go off anddo. But to put it even more simply, thereare two independent questions as to
how the market for efficient electronicproducts can (and should) play out. The first is whether or not the consumermust purchase a truly efficient product,and the second is whose efficient prod-uct they will buy. Certainly, it won’t hurta company to work diligently to cost-reduce their product as much as possi-ble, purely from a competitive standpointrelative to other suppliers of similarproducts. But it wouldn’t hurt either todevote some resource to lobbying forthe doubling or tripling of the availablemarket, either. And that is my call to action.
What are the suppliers’ lobbyingoptions? Among them will be for individ-ual companies to try to lobby alone,which would be expensive for any onecompany to take on, and the resultswould might also end up being a bit self-serving. Alternatively, the power man-agement industry (or various applica-tion-specific groups therein) could bandtogether into consortia to do the job; thiswould certainly be more objective, butthe challenge there would be logistics,politics and/or bureaucracy. But the benefits would be worth the effort. Someexisting groups (e.g., PSMA) are search-ing for most effective ways to add valueto their industry—perhaps this would bea productive direction in which to move,and an expedient means for doing so.Or perhaps it would make sense to forma more comprehensive power manage-ment suppliers’ association.
In closing, there is ample evidenceand historical experience in the powermanagement market to clearly illustratethe positive role that incentives, volun-tary guidelines, government policies,and legislated standards can have in thesimultaneous growth of the market andthe improvement of efficiency across theconsumer base. That experience alsoillustrates a couple of potential pitfalls—that we should work intelligently to avoidand to do this, we will need to becomenot merely lobbyists, but excellent,aggressive lobbyists.
Some would argue that we’re takingaway the consumer’s choice. This is thestatesman’s dilemma of ages: do I do
what the populace wants, or do I dowhat’s right?
We can extend the argument to powerfactor correction. PFC will NEVER beinitial-cost neutral to the consumer. Sousing the cost-neutral logic, we’ll neverhave widespread adoption of PFC. Isthat what’s best for the world and for theconsumer? Of course not. Now, wecould spend the next 20 years trying toexplain to every person out there thevirtues of a zero phase angle—or wecould just legislate it and be done with it.
Now, that’s efficiency.
Christopher Ambarian is a senior analyst with the market research firmiSuppli Corp., El Segundo, Calif.
Contact him at [email protected]
www.iSuppli.com
Figure 2. A summary of market adoption drivers for efficient electronic solutions. Legislation is ranked highest, due to largestpotential impact on growth and environment.
16 Power Systems Design Europe January/February 2006
COVER STORY
Lightly loaded standby or no-load modes
After July 1, 2006, new products with external power supplies sold into California must meet new mandatory active efficiency and no-load limits. Several other US states as
well as Australia, Europe and China have either implemented mandatory regulations or are considering such moves.
By Peter Vaughn, Product Applications Manager, Power Integrations
Engineers are constantly chal-lenged to reduce the cost andsize of the products that they
design and to achieve this in ever-short-er design cycles. Power supply design-ers, ‘enjoy’ the added challenge of newenergy efficiency regulations that man-date high efficiency even in lightlyloaded standby or no-load modes.
Although mostly voluntary, there isnew trend towards regulations withmandatory limits. For example, afterJuly 1, 2006, new products with externalpower supplies sold into California mustmeet new mandatory active efficiencyand no-load limits. Several other USstates as well as Australia, Europe andChina have either implemented manda-tory regulations or are considering suchmoves. Even voluntary standardsenable the opportunity to label a productEnergy-Efficient, resulting in a competi-tive advantage. And many manufactur-ers simply choose to work to the moststringent limits to ensure that a singledesign will be acceptable worldwide,eliminating design variants.
The challenge for semiconductorcompanies is to create solutions thatprovide a lower system cost, better
energy efficiency, and safe and reliableperformance, whilst simplifying thedesign process and increasing designflexibility in order to reduce the engi-neering effort required to create a newdesign. Merely reducing the cost of thelast generation of products is not enough.
It was this challenge that shaped thedevelopment of the new TinySwitch-IIIintegrated switching power supply ICfamily from Power Integrations. As withprevious power conversion IC familiesfor the company, TinySwitch-III inte-grates a 700 V power MOSFET, oscilla-tor, high voltage switched current
source, current limit (user selectable)and thermal shutdown circuitry into asingle IC and uses On/Off control to regulate the output.
Important new features and enhance-ment have been added to the latestgeneration of the TinySwitch family,resulting in higher power capability andimproved performance. Power capabilityof up to 28 W for 85-265 VAC and 36 Wfor 230 VAC input compared to the 15W and 23 W previously achieved (Fig. 1).The revised pin-out enables improvedcreepage distance and heatsinking.
Figure 1. TinySwitch-III power table and package outline.
18
COVER STORY
Design ExampleTo illustrate the new features and
enhancements in detail figure 2 shows a12 W, universal input flyback power sup-ply using a TNY 278 device. This designmeets all current energy efficiency and no-load input requirements plus isproduction worthy meeting CIPR22/EN55022 B conducted EMI limits with>12 dB margin and EN1000-4-5 Class 3line surge.
When power is first applied the incom-ing AC is rectified and filtered creating aDC voltage across C2. The BYPASS/MULTI-FUNCTION (BP/M) pin capacitorC7 is charged via a switched high volt-age current source connected internallybetween the DRAIN and BP/M, remov-ing the need for external components.Once the IC begins normal operationMOSFET switching transfers energy tothe secondary where it is rectified andfiltered by D7 and C10.
An optional under-voltage lockupresistor, R5, can be used to program thestart up voltage. TinySwitch-III sensesthe presence of the resistor and inhibitsswitching until a current of 25μA flowsinto the pin. This ensures that the input
voltage is high enough for the output toreach regulation at startup and preventsthe output glitching at power down, as the input capacitors discharge. Thevalue of 25 μA minimizes the steadystate dissipation in the resistor to about10 mW at 375 VDC, important toachieve low no-load consumption.
TinySwitch-III devices are self-poweredand therefore do not require an auxiliarybias winding on the transformer to providethe IC supply current. Instead, a localdecoupling capacitor (C7) is chargedfrom the DRAIN pin during the off-timeof the internal MOSFET. By minimizingthe power consumption of the IC, a no-load input power of <140 mW at 265VAC input was achieved when no auxil-iary/bias winding is present (R8 removed).
However, the addition of a bias wind-ing allows the IC to be supplied from alower voltage. In figure 2, the bias wind-ing is rectified and filtered by D6 and C6and fed into the BP/M via resistor R8.This disables the internal high voltagecurrent source after startup and the no-load input power is reduced down toless than 45 mW at 265 VAC.
A bias winding also allows the config-uration of the output over-voltage shut-down protection feature via the BP/Mpin. A current into the BP/M pin thatexceeds 5 mA for greater than 30 μstriggers an internal latch and disablesthe internal MOSFET. This protects theload should an open loop fault conditionoccur, for example due to failure of theoptocoupler, removing the cost of exter-nal components. The 30 μs filter pre-vents false triggering due to noise.
The output over-voltage is sensed onthe primary side via the bias windingwhich tracks the output voltage accord-ing to the turns ratio between the wind-ings. Once the output voltage exceedsthe threshold set by VR2, current flowsinto the BP/M pin and triggers shut-down. To reset, the AC input must beremoved for long enough for the inputcapacitors (C1 and C2) to discharge. In the design shown, the over-voltagetriggers at an output voltage of 17 V.
Selectable Current Limit for DesignFlexibility
As well as being the VCC pin andlatching shutdown input, the BP/M pinalso allows selection of the internal
Figure 2. TinySwitch-III schematic implementing a 12 V, 1 A design.
Power Systems Design Europe January/February 2006
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This reduces the dissipation of the out-put diode, clamp components and trans-former during fault conditions. It alsoreduces the power rating and cost of thezener needed to provide very accurateclamping of the output voltage duringopen loop conditions.
Thermal shutdown provides overloadprotection by shutting down the supplyonce the IC temperature reaches 142 C.This function can be use to protect thewhole supply by sizing the heatsinkingof other key components to be accept-able at point that the TinySwitch-IIIreaches thermal shutdown. Unlike mostthermal shutdown functions, which areeither latching or hysteretic with only afew degrees of hysteresis, TinySwitch-IIIhas a hysteresis of 75 C. This avoidsthe problem of latching thermal shut-down where the end user may return agood power supply that latched off dueto being under a pile of clothes, or in thesun (real examples). It also preventsexcessive device temperature, as is thecase when there are only a few degreesof hysteresis. Here the package essen-tially sits close to the shutdown temper-ature and may cause permanent dam-age to low cost PC board material. A 75C hysteresis ensures the average boardtemperature is <100 C while still provid-ing automatic recovery when the over-load is removed or the supply movedout of the sunlight.
During normal operation the peak pri-mary current is terminated by currentlimit. However during brownout condi-tions or on removal of the AC input, thecurrent limit may not be reached and thecycle is terminated by maximum dutycycle. As power delivery is a function ofthe peak primary current squared, smallreductions in the peak primary currentsignificantly reduce the power deliveredto the load. TinySwitch-III detects thiscondition and enables the on-timeextension feature. This enables currentlimit to be reached independent of theDC bus voltage, maximizing powerdelivery and improving holdup time.Figure 5 shows the impact of on-timeextension on hold-up time.
On-time extension has a second ben-efit. In a design that operates in deeplycontinuous conduction mode, it maytake several cycles for the primary cur-rent to build and reach current limit. Thiscreates a stronger audible component atthe frequency cycles are being skipped.On-time extension prevents this byallowing the current to ramp to currentlimit within one cycle. This becomesespecially important in higher powerdesigns where the larger cores requiredcreate higher levels of audible noise.
TinySwitch-III features a single, tighttolerance I2f power delivery term. Thiseliminates the need to design for theworst-case combination of current limit
and switching frequency and dramatical-ly reduces the design effort needed totolerance a design. This allows up to 6% more power from a given core size,reduces device conduction losses by up to 3% as well as reducing overloadpower when compared to individual tolerance for current limit of +/-7% and+-6% for switching frequency forTinySwitch-II.
TinySwitch-III offers a significant stepforward in reducing the complexity andcost of a switching power supply, meet-ing the need for a lower componentcount, lower system cost, higher effi-ciency, and lower no-load input powersolution. Selectable current limit levelsoffer design simplicity, flexibility andreduced time to market. Built-in protec-tion features reduce component costand offer enhanced product safety.
COVER STORY
Figure 5. Comparison of a design with and without the on-time extension feature, showing 20% improvement in hold-up time.
www.powerint.com
current limit value. Figure 3 shows atable of current limit values vs. BP/M pincapacitor. By selecting one of three val-ues of capacitor, one of three currentlimit values can be selected, providinggreater design flexibility. The standardcurrent limit (std ILIM) is optimized forapplications in enclosed adapters wheredissipation has to be limited due to ther-mal rise. If lower dissipation and higherefficiency are required, then the lowercurrent limit (ILIM-1) can be programmedto reduce MOSFET conduction losses.The selection of the higher current limit(ILIM+1) allows the design to delivergreater power. This can be continuouswhere the thermal environment allows(such as open frame supplies) or where short-term peaks are required tostart up motors (such as DVD players or DVRs).
Figure 3 also demonstrates thematching of current limits value betweenadjacent family members; this allowsthe next smaller and larger family mem-ber to be used in the same design byselecting the same current limit. This isuseful during development, allowing dif-ferent devices to be evaluated and theoptimum device to be selected withoutthe headache of a transformer redesign.
If the transformer is initially designedfor the next higher current limit level, asis the case in the design example, a single platform can be used to cover awide range of output powers. Figure 4
illustrates the impact of current limit onefficiency, showing that this design easily meets the California EnergyCommission/Energy Star externalpower supply requirement of an aver-age efficiency of above 71.3%.
The output is regulated using On/Offcontrol. When the output voltageexceeds the voltage determined byVR2, R6 and the LED in U2 turns onand current is pulled from the ENABLE/UNDER VOLTAGE (EN/UV) pin. TheEN/UV pin current is sampled, just priorto each switching cycle. If the pin cur-rent is < 90 μA, the next switching cycleis enable, terminated when the currentthrough the MOSFET reaches the internal current limit. To evenly spreadswitching cycle, preventing group puls-ing, the EN pin threshold current ismodulated between 50 μA and 90 μAbased on the state of the EN pin duringthe previous switching cycle.
On/Off control eliminates the need forloop compensation components whileproviding a high loop bandwidth andexcellent transient response. The currentthrough the feedback zener is essential-ly constant, set by R4. This allows azener to give good load regulation, asthe zener voltage is not being altered byvariations in feedback current, as wouldbe the case in PWM control.
Depending on the load, the internalcontroller selects one of 4 current limit
levels, the highest being the specifiedcurrent limit. This ensures the effectiveswitching frequency stays above theaudible range until the transformer fluxdensity, and hence audible noise gener-ation, is low. This, together with standardproduction dip-varnished transformers,practically eliminates audible noise.
By optimizing the switching frequencybased on the load, TinySwitch-III offersconstant efficiency operation, maintain-ing high efficiency even down to verylow loads. This is ideal when trying tomeet active mode average efficiency orto maximize available output for a fixedinput power limit in standby conditions.
The switching frequency of 132 kHz is jittered by +/-8 kHz to spread EMIenergy over a wider frequency rangeand thereby reduce EMI emissions. This reduces the size, number and costof EMI components. Frequency jitter combined with innovative techniques inthe transformer design, allow conductedEMI limits to be met with a simple pi filter on the input (C1, L1 and C2) and Y class capacitor, C5.
Auto-restart limits the output powerduring a fault condition. If no feedbackis received due to an output overload,short circuit, or open loop fault for >64ms, the IC enters auto-restart, alternate-ly disabling the MOSFET for 2.5 s andenabling it for 64 ms and limiting theoutput power to <3% of maximum.
COVER STORY
Figure 3. Selectable current limits give designflexibility.
Figure 4.Trade off between device size, current limit, efficiency andpower delivery.
22 Power Systems Design Europe January/February 2006
The 3300V module will be followed by the 4500V class
ABB introduces HiPak modules utilising the new SPT+ IGBT chips with voltage ratings up to4500V and current ratings up to 3600A. The SPT+ IGBT HiPak modules achieve the same
desirable switching characteristics as the current SPT generation, while exhibiting lower over-all losses for increased current ratings.
By Eric Carroll and Munaf Rahimo, ABB Switzerland Ltd, Semiconductors, Switzerland
The power electronics communityhas a long wish-list of improve-ments for the IGBT in terms of
losses, ruggedness and controllability. A trend towards the use of Trench celldesigns and thinner base structures,seen as the only options for reducinglosses, has overlooked the need forgreater Safe Operating Area (SOA) andsmooth switching behaviour. RecentSPT IGBT developments at ABB have,in fact, resulted in major improvementsin ruggedness and softness.
Furthermore, the recent launch of theSPT+ enhanced planar technology hasfinally combined solutions for the reduc-tion of losses and the dramatic increaseof SOA while bucking the former trendutilising Trench cell designs. In 2005ABB introduced the SPT+ IGBT technol-ogy and here we present SPT+ HiPakmodules, shown in Figure 1, which setnew standards in both efficiency andruggedness.
SPT+ IGBT Planar TechnologyThe next generation SPT+ IGBT plat-
form has been designed to substantiallyreduce the on-state voltage while main-taining low levels of switching losses.This approach combines a carefully
selected trade-off for high immunity tocosmic ray failures and smooth switch-ing behaviour while maintaining the highturn-off ruggedness (RBSOA) alreadyachieved by the current SPT technology.The new SPT+ platform exploits anenhanced carrier profile through planarcell optimisation, which is compatiblewith our advanced and extremelyrugged cell design. The new technologyleads to a significant increase in plasmaconcentration at the emitter and thus, alower on-state voltage is obtained forthe same turn-off loss. In addition, anoptimised base region combined withthe Soft-Punch-Through (SPT) bufferallows the collector current to smoothlydecrease during the turn-off transientthanks to the progressive and controlled
manner in which the depletion layer isestablished. The new SPT buffer and anoptimal anode design, further ensuresgood short-circuit controllability with ahigh Short Circuit Safe Operating Area(SCSOA). Thanks to the combination ofan enhanced cell design and the SPTconcept, the SPT+ IGBT technologyplatform has enabled ABB to establish anew benchmark in the technology curveover the whole IGBT voltage range.
Figure 2 compares SPT+ with the current SPT technology for the voltagerange 1200V to 4500V. The values forVce,sat are obtained at the same currentdensities and for similar turn-off losses,for each voltage class. Thereforedemonstrating that SPT+ technologywith an optimised planar structure canmatch the carrier profile of trench-gatecathode designs. It is also important tostress that the reduction in on-state loss is achieved exclusively throughenhancement of the carrier profile nearthe cell (emitter) while maintaining thesame drift region thickness of the stan-dard design. This is essential for ensur-ing controllable and “soft” switchingbehaviour, which in turn is necessary for very high current modules. Thereduction in Vce,sat due to SPT+ cell
IGBT MODULES
Figure 1. HiPak modules.
www.powersystemsdesign.com 2524 Power Systems Design Europe January/February 2006
Figure 5a and Figure 5b show theturn-on and turn-off waveforms respec-tively at 125°C at the rated current of1500A and a DC-link voltage of 1800V.The current switching transients main-tain very smooth waveforms and a shortcurrent tail with no “snap-off”. Due to thetail duration being short, the turn-off lossis limited to only 2.4 Joules. The 3300V
SPT+ IGBT and freewheeling diodewere also optimised for low IGBT turn-on losses, Eon, through a combination oflow IGBT input capacitance (for fasterVce fall times) and low diode reverserecovery charge. The turn-on losseshave typical values of 2.0 Joules undernominal conditions at 125°C.
The RBSOA test at 125°C was carriedout at a current level of 4800A (>3 timesnominal) against a DC-link voltage of2600V as shown in Fig. 6a. The deviceclearly exhibits a high capability forstrong dynamic avalanche under theseextreme conditions. Successful opera-tion in Switching-Self-Clamping-ModeSSCM was also obtained with a self-clampvoltage of 3450V for approximately1μsec. By enabling the IGBT module towithstand SSCM, the device exhibits asquare SOA capability up to the self-clamp voltage level. The high dynamicruggedness, combined with smooth
switching behaviour gives users thegreatest freedom possible in designingsystems without dv/dt or peak-voltagelimiters such as snubbers or clamps.Another major advantage of an extreme-ly rugged IGBT is that it allows operationwith much lower gate-resistance than thatrequired by conventional technologies.This results in shorter delay times dur-ing device turn-off, which not only low-ers the turn-off losses but also improvescurrent sharing between individual IGBTchips in the module and ultimately,between parallel connected modules.The short circuit test result of Figure 6bat 125°C demonstrates controllable and”clean” current and voltage waveforms,which exhibit no parasitic oscillations.The waveforms show the 1500V/3300VSPT+ HiPak in short-circuit mode at aDC-link voltage of 2600V for an extend-ed current pulse of 14μsec. The currentwaveform shows an average short-cir-cuit current of approximately 6500A.
enhancement ranges from 15% for a1200V IGBT up to 30% for a 4500Vdevice, allowing corresponding increas-es in current ratings. In this article, wewill briefly demonstrate some of the keyelectrical characteristics of the new3600A/1700V and 1500A/3300V SPT+
HiPak modules.
3600A/1700V SPT+ HiPakModule
We will first discuss theresults obtained for the3600A/1700V SPT+ HiPakmodule. The SPT+ technolo-gy retains all the desired SPTcharacteristics while simplyreducing conduction losses.Thus the new module is nowrated at 3600A using same-sized chips or alternatively,the present 2400A modulecan be made with 30% small-er chips. Table (1) comparesthe current densities andlosses of the standard SPTHiPak with those of the new
SPT+ module. It can be seen that forthe same Vce,sat (at rated current), themodule rating is increased from 2400Ato 3600A. The SPT+ module has anon-state voltage drop (at chip level) of2.6V at 125°C. The new IGBT exhibitsthe same strong positive temperaturecoefficient of Vce,sat as the presenttypes, which is essential for ensuringgood current sharing in demanding par-alleling conditions.
The 3600A/1700V SPT+ moduleswere subjected to a series of dynamictests to demonstrate their electrical
capability. In Figure 3a and Figure 3b,the turn-on and turn-off waveformsunder nominal conditions (900V/3600A)at 125°C can be seen respectively. TheIGBT and the diode both exhibit soft andcontrolled switching characteristics aswell as short current tails. This behav-iour is the combined result of the SPT
buffer design and silicon specificationused in SPT+ technology leading to fastswitching, low losses, low overshootvoltages and low EMI levels. TheRBSOA turn-off waveforms are shown inFigure 4a. The device was tested at aDC-link voltage of 1200V and 8000A at125°C. A self-clamp overshoot voltageof 1900V can be observed during theturn-off period. The high SOA obtainedunder such extreme conditions confirmsthe module’s robustness. The short cir-cuit test at 125°C and at a DC-link volt-age of 1300V can be seen in Figure 4b.
1500A/3300V SPT+ HiPak ModuleDue to the significant challenge in the
design of high voltage devices regardingruggedness and softness, the main goalof the new technology development wasto achieve loss reductions without sacri-ficing either soft switching behaviour orthe benchmark robust performance ofthe current SPT generation. With thesame silicon specification, SPT bufferand enhanced planar design, thesegoals were met or even exceeded forRBSOA despite the lower saturationvoltages. Compared to current 3300VSPT IGBTs, the new SPT+ IGBT offers25% lower on-state losses while main-taining low turn-off losses and thus setsa new benchmark for 3300V IGBT per-formance. Table (2) compares 3300VHiPak modules and shows that despitean increase in current rating of 20%, theSPT+ module still allows reductions inconduction losses from 3.8V at 1200A to3.0V at 1500A.
Figure 2. SPT and SPT+ IGBT on-state voltage vs.rated blocking voltage at 125°C.
Figure 3a. Turn-on waveforms 3600A/1700V HiPak switching characteristics at 125°C.
Figure 3b. Turn-off waveforms 3600A/1700V HiPak switching characteristics at 125°C.
Table 1. Comparison of SPT and SPT+
IGBT 1700 volt HiPack2.
Figure 4a. RBSOA 3600A/1700V HiPak switching charac-teristics under SOA conditions at 125°C.
Figure 4b. SCSOA 3600A/1700V HiPak switching charac-teristics under SOA conditions at 125°C.
Table 2. Comparison of SPT and SPT+
IGBT 3300 volt HiPack2.
Figure 5a. Turn-on waveforms 1500A/3300V HiPak switch-ing characteristics at 125°C.
Figure 5b. Turn-off waveforms 1500A/3300V HiPak switch-ing characteristics at 125°C.
IGBT MODULES IGBT MODULES
www.powersystemsdesign.com 2726 Power Systems Design Europe January/February 2006
Evolution step of inrush current limitingHigh availability systems must operate continuously without interruptions in service. To achievethis level of reliability in large systems with many circuit cards in a chassis, you must be able to
add new cards and replace obsolete or damaged cards without powering down the system.
By Chris Umminger and Todd Nelson, Linear Technology
However, removal and insertion of cards into a live backplane isfraught with potential problems.
Backplanes often have significant induc-tance between the card connectors and the power supply capacitance.Disconnecting a card that is still drawingload current can induce ringing and highvoltage spikes along the backplane,potentially disrupting or even damagingnearby boards. In higher voltage appli-cations, such as 48V distribution sys-tems, the removal of a card can draw anarc that damages connector contacts.Even worse, when a new card is insert-ed and the power rails first mate, unlim-ited backplane currents charge the cardcapacitance and induce ruinous tran-sient surges. A variety of circuits haveevolved to safely “hot” swap cards inthese systems.
Evolution of Hot Swap SolutionsPlacing a switch M1 between the
backplane and the card’s bulk capaci-tance as shown in Figure 1 addressesseveral hot swap problems. Turning thisswitch off and on in a controlled mannerminimizes the disturbance to the back-plane supply voltages. During insertion,the switch is initially held off by R1. Afterthe power rails have made contact, theshort pin connects and charges C1through R2 to turn on the switch. ClampZ1 limits the gate voltage of M1 to asafe value. When the card is extracted,
the short pin disconnects first, allowingR1 to slowly turn off M1.
This simple circuit has several weak-nesses. First, although a slow risingwaveform appears at the gate of M1,the large gain of the power transistorcauses the output voltage to rise at amuch faster rate. Thus, unrealisticallylarge values are required for R1, R2,and C1 to achieve a satisfactory turn-onrate. Second, the turn-off of M1 via R1is very slow, perhaps longer than thetime taken to extract the card. Thus, theswitch could still be allowing current toflow when the long pins break connec-tion. Third, if the card should short cir-cuit or overload, the only protection isslow acting fuse F1. Finally, in a positivevoltage system, this circuit must use a
P-type MOSFET for M1, which is gener-ally not as cost effective as using an N-type device.
Early integrated hot swap controllerssuch as the LT1640 illustrated in Figure2 address many of these problems.When the short pin makes contact, thecontroller turns on the switch with afixed 45uA current source. Initially thischarges the MOSFET gate until theMOSFET turns on.
When the output voltage starts tochange, the current is diverted to chargethe gate-to-drain capacitor C2. Thechoice of C2 accurately sets the outputvoltage slew rate and hence the inrushcurrent. During extraction, the controllerquickly turns off the MOSFET switch
Figure 1. A passive hot swap circuit softens the connection of power to a card.
POWER MANAGEMENT
The presented SPT+ HiPaks will givesystem designers greater freedom inachieving higher power and better effi-ciency for their applications. HiPak prod-ucts with SPT+ IGBT chips will becomecommercially available in 2006 in volt-age classes ranging from 1200V to4500V. This will coincide with the intro-duction of the smaller HiPak1 in theindustry standard 130 x 140 mm foot-
print. Along with the current single-switch and chopper configurations of the190 x 140 mm housing (HiPak2), theHipak1 will also offer dual IGBT anddual diode configurations in both stan-dard isolation and high isolation hous-ings (VISOL = 10.2 kV). The 3300V mod-ule now being sampled will be the firstcommercially available 1500A version ofthis popular voltage class. It will be fol-
lowed in mid-year by the 4500V classaccompanied by the general release ofthe HiPak1 family.
Figure 6a. RBSOA - 1500A/3300V HiPak switching charac-teristics under SOA conditions at 125°C.
Figure 6b. SCSOA - 1500A/3300V HiPak switching charac-teristics under SOA conditions at 125°C.
www.abb.com/semiconductors
IGBT MODULES
Power Systems Design Europe January/February 2006
before the connector contacts open.Additionally, the current sense resistorRs combined with comparator A1 forman electronic circuit breaker that turnsoff the switch if the load current exceedsa set limit. For positive voltage systems,devices like the LTC1422 also provide acharge pump to drive less expensive N-type MOSFETs for the high side power rail.
Many systems have short durationsupply transients that are part of normaloperation. For example, telecom sys-tems may switch over between redun-dant supplies resulting in a several voltstep in the card input voltage. In systemswith motors, such as disk drives, therecan be large, short duration currents asthe motor starts. These events maycause the load current to exceed the cir-cuit breaker threshold momentarily andfalsely shut off the switch. The secondgeneration of hot swap controllersevolved to distinguish between real faultsand operating transients and provideappropriate fault protection. Convertingthe comparator shown in Figure 2 intoan amplifier that actively limits currentsolves this issue. Devices such as theLT4250 limit the current to a safe valueand then shut off the switch if the faultpersists beyond a set timer period.
Further improvements simplify the hotswap circuit by actively limiting currentduring both inrush and output overloads.This allows you to eliminate the capaci-tor C2 and bring up the output voltage
more quickly. Often the current limittimer is adjustable, so you can matchthe duration of overload with the specificneeds of the system and the ruggednessof the MOSFET. Examples of such partsare the LTC4252A for -48V systems andthe LT4256 for positive voltage systems.
Digital Monitoring—A New Era forHot Swap Controllers
Adding Intelligence ImprovesReliability. In complex high availabilityapplications, it is increasingly importantto monitor system power for a couple of reasons. First, you can watch foranomalous trends over time that indi-cate abnormal operation and anticipateimpending failures. Second, it is com-mon today for systems to allocate powerbetween different card types to econo-mize on total power supply capacity.Power monitoring ensures that the cardsstay within their allotment. Residing atthe power connector, the hot swap circuitis a natural place to monitor the powerentering a card.
The latest generation of hot swapcontrollers, such as the LTC4260 andLTC4261, make power monitoring easy.In addition to the core hot swap func-tions of inrush current control and elec-tronic circuit breaker, the LTC4261 (illus-trated in Figure 3) incorporates a 10-bitanalog to digital converter, multiplexor,preamplifer circuitry, and digital interfacethat enable an unprecedented level ofmonitoring and control. This device
Figure 2. Early hot swap controllers limit inrush current more accurately, turn offfaster when disconnecting, and include an electronic circuit breaker.
www.powersystemsdesign.com30 Power Systems Design Europe January/February 2006
measures input voltage and voltageacross the current sense resistor.Knowing voltage and current lets youdetermine power in the card andobserve trends. Furthermore, you canuse an additional free data converterinput for additional measurements suchas the voltage across the MOSFET orthe status of the input fuses.
Incorporating a digital interface addsfeatures far beyond monitoring card
power. You can issue instructions to thedevice to control power as well as con-figure and report a variety of faultbehaviors. For example, the switchmight be turned off due to a fault suchas an undervoltage condition on thebackplane. In this case, a flag is set thatyou can later read to determine thecause of failure. It is also possible togenerate an “alert” that will pull an inter-rupt line low to inform the system of afault. Additionally, you can configure
which faults will cause the card to turnoff permanently or attempt to power upagain automatically. For example, sys-tems that are remote or difficult to serv-ice may prefer to allow a card to restarton its own when an undervoltage situa-tion has ended.
This information is accessible in twoways. First, you can use the popular I2Cbus to read and write to the registers. In–48V systems this often means trans-mitting the data across an isolation bar-rier to the I2C master. The LTC4261separates the transmit and receive datapins (SDAO and SDAI) to simplify theisolation circuitry. Second, you maychoose to reduce costs further by takingadvantage of the single wire broadcastmode. In this case, a single output pinand external optoisolator transmit arepeating datastream that divulges thecontents of the registers and the voltageand current measurements.
Monitor a Wide Variety of FaultsModern hot swap controllers monitor a
wide variety of faults in addition to over-current. In -48V systems there are oftenstringent requirements for the allowedoperating voltage to protect the load.The two undervoltage inputs UVH andUVL let you independently select a turnon voltage, such as -43V, from a turn off
Figure 3. The latest hot swap controllers include digital interfaces to measure current and voltage along with improved cur-rent limiting, fault monitors, and power good signals.
POWER MANAGEMENT
Figure 4. Oscilloscope waveforms show the LTC4261 waits until connectionbounce is complete before smoothly powering up the load.
voltage, such as -38V. The overvoltageinput OV turns off the switch if the inputvoltage is too high.
The LTC4261 simplifies and ensuresthe proper start-up of power to the load.It generates delayed power good signalsthat start loads in sequence after theMOSFET switch has brought up thecard power supply. Subsequently, apower-up timer is started. A systemmonitor must come back and stop thistimer to indicate normal operation. If thetimer finishes without receiving this sig-nal, due to system start-up failure, thepower is turned off.
Soft Start and Separate InrushCurrent Limit Improve Connection
In addition to the many new monitor-ing features, improvements continue inthe basic inrush control function. In cer-tain applications with significant back-plane inductance, you must not onlycontrol the inrush current but also limitthe rate of rise (dI/dt) of inrush current tominimize disturbance to the backplane.Current limit circuits now incorporate asoft start function to limit dI/dt controlledby the choice of an external capacitor, Css.
Another improvement separates theinrush current limit during insertion fromthe active current limit used by the cir-cuit breaker. In systems with high loadcurrents, a large amount of load capaci-tance may be present. Charging thiscapacitance to 48V, for example, storesa considerable amount of energy. Anequal amount of energy is dissipated inthe MOSFET switch during start-up,which is its most significant stress. TheLTC4261 lets you define the circuitbreaker current limit, set with Rs, inde-pendent of the inrush current, which youset with the value of C2. Thus, you canpower up large load capacitances whileminimizing MOSFET power dissipationand size. Figure 4 shows the LTC4261starting up a -48V card after insertion.
Safely managing power during liveinsertion of cards is a critical feature ofhigh availability systems. A variety of circuit improvements have been madeover the years to ensure this occurs reliably. Early hot swap circuits crudely
limited inrush current. Laterimprovements added an electroniccircuit breaker to isolate faults, com-parators to monitor voltage levels,and power good signals to safelystart the load. Today, these circuitshave digital interfaces with on-boarddata converters that allow systemsto continuously monitor and managethe power. With this information, youcan design systems to reach thenext level of reliability and durability.
www.linear.com
32 Power Systems Design Europe January/February 2006
This article describes a new precision power analyser which features the world’s highest measurement accuracy (±0.02% of reading) and a measurement bandwidth
of 0.1 Hz-1 MHz as well as DC signals.
By Iwase Hisashi, Itou Osamu and Tachibana Katsuya, Yokogawa
To find use in many types of power measurement applications
The instrument can be equippedwith four input elements, and it ispossible to measure the efficiency
of a DC-input 3-phase invertor with asingle unit, thereby enabling highlyaccurate measurement of the efficiencyof invertors installed on electric vehicles,for example. A large-format LCD enablesthe analyser to display measured valuesin various forms, including waveforms,for greater operability.
In recent years, the demand for energy-efficient machinery and equipmentdesigned to address global environmen-tal problems and to effectively utiliseenergy resources has been increasing.In Japan, for example, the law concern-ing rational use of energy was revised inresponse to the Conference of PartiesIII (COP3) conference on global warm-ing, which was hosted by Kyoto inDecember 1997. The JapaneseGovernment ratified the Kyoto Protocolin June 2002. Internationally, the EnergyStar Program was launched in 1995.The energy efficiency standard of thisprogram applies to home appliancesand office automation equipment. Nowthat hybrid automobiles, invertor-drivenrefrigerators and air conditioners arewidespread, greater accuracy is neededin power measurement.
The instrument described in this articlemeets the demands of the high-accura-cy power measurement market by offer-ing the world’s highest accuracy forpower measurement (Figure1).
Key features of the new instrumentinclude:High accuracy and bandwidth: The basicaccuracy, i.e. the accuracy of measure-ments at commercial frequencies of 50/60 Hz, is ±(0.02% of reading and +0.04%of range). The frequency bandwidth cov-ers 0.1 Hz-1 MHz as well as DC signals.
Maximum of four input elements: Sincethe analyser can be equipped with amaximum of four input elements, oneunit can measure the inputs and outputsof a three-phase invertor. With two units,multi-channel power measurement canbe performed on a synchronized basis.
Common-mode voltage of 1000 V:Earlier power analysers have used pho-tocouplers to insulate the input circuit,which has limited the common-modevoltage to 600 V. The new instrumentemploys a newly developed pulse
Figure 1. The Yokogawa WT3000 precision power meter.
POWER MEASUREMENT
www.powersystemsdesign.com 35
Measurement functionThe key measurement functions of thenew analyser are as follows:
Simultaneous measurement of normaland harmonic waveforms: To measureharmonic waves on earlier instruments,
it was necessary to change to a dedicat-ed harmonic wave measurement mode.For users who wish to acquire measure-ment data related to harmonic wavessuch as THD (distortion factor) in addi-tion to voltage, current, and power,
changing measurement modes not onlylowers throughput but also causes aloss of the synchronicity of measureddata. New instrument overcomes theseconstraints by using the 200 kHz sam-pling clock which is normally used for
34 Power Systems Design Europe January/February 2006
transformer for input circuit insulation.By maintaining a sufficient insulationdistance, a common-mode voltage of1000 V has been achieved, enablingmeasurement of the ever-increasingdrive voltages in modern invertors.
High-speed data update: The maximumdata update period of the new analyseris 50 ms: five times the speed of earlierinstruments. This feature is useful inevaluating the characteristics of motorssuch as torque and speed of rotation. Itis also effective in measuring phenome-na that tend to change in a relativelyshort period of time or at high frequen-cies (e.g. ramp currents and secondaryvoltages in lighting systems).
Motor evaluation: A motor evaluationfunction is available as an option on theanalyser. This allows the analogue orpulse output of the torque and the rota-tion speed to be input directly from atorque meter into the instrument. Torqueand rotation speed readings as well asmotor output, synchronous speed, slid-ing, motor input/output efficiency, andinvertor-input/motor-output efficiencyare then calculated to measure the totalefficiency of the invertor and the motor.
Instrument configurationFigure 2 shows the basic configurationof the power analyser. The main compo-nents are the DSP, the CPU, and the fourinput elements, which include voltageand current input circuits. Other compo-nents include the LCD display, the key-pad, and the GP-IB for communication.
The voltage input circuit is a resistance-voltage-division configuration, while thecurrent input circuit is of the shunt-resis-tor type. Inputs into each are normalisedand in turn entered into the A/D conver-tor by the operational amplifier. The con-version rate is approximately 5 μs.
The input resistance of the voltage inputcircuit is 10 MΩ, which is five times larg-er than that of earlier instruments. As aresult, losses in the instrument arereduced, and the effects of self-heatingcaused by high-voltage input are min-imised. To increase the measurementbandwidth while maintaining the inputresistance at 10 MΩ, input resistorshield cases are used so that capacitorsare formed between their terminals.
The shunt resistor of the current inputcircuit employs a coaxial structure toincrease the measurement bandwidth.The shunt resistance of such a structuretends to fluctuate greatly with changesin applied power, so development effortshave been aimed at minimising changesin shunt resistance.
The outputs from the A/D convertor areinsulated by the pulse transformers andinput into the DSP, which calculatesmeasurements of voltage RMS, currentRMS, effective power etc. These calcu-lations are carried out in real time, whichreduces any dead time during powermeasurement. The ‘delta’ DSP performsthe calculations for Δ/Y conversion in 3-phase measurements, while the‘math’ DSP carries out the calculationsfor harmonic wave analysis.
The values measured by the DSP areprocessed by the CPU for display, com-munication and D/A output purposes.
Figure 3 shows voltage and currenterror curves with respect to frequency,while Figure 4 shows a power errorcurve with respect to frequency.
Figure 2. Schematic of the WT3000 precision power meter.
Figure 3. Voltage and current error curves with respectto frequency.
Figure 4. Power error curve with respect to frequency.
POWER MEASUREMENT POWER MEASUREMENT
www.powersystemsdesign.com 3736 Power Systems Design Europe January/February 2006
measurement. For data acquisition, thenumber of pulses generated by thesampling clock is reduced, so that thegenerated signals are nearly equal tothe PLL (phase-locked-loop) clock sig-nals of the input sources. The FFT (FastFourier Transform) calculation is execut-ed using the dedicated DSP concurrent-ly with data acquisition.
Combined use of digital filtering andtotal averaging: Previous power analy-sers have used a digital filtering methodin which multiple exponential averagingis executed for sampled instantaneousvalues. The accuracy of this method isgreater than that of the total-averagingmethod, in which instantaneous valuesin the measured section are summed foraveraging. However, the accuracy ofdigital filtering is low for data updateperiods below 250 ms when the fre-quency of data input is mainly in thecommercial frequency range.
Data update periods of 50 ms and100 ms are difficult to achieve with digi-tal filtering. Therefore, the new analyseruses the total-averaging method forthese periods to meet the needs ofusers who require high-speed respons-es, even if the accuracy must be com-promised to a certain extent.
To enable measurement at frequenciesabove 0.1 Hz, the maximum dataupdate period is set at 20 sec. Thus thedata update periods of the analyser are
50 ms, 100 ms, 250 ms, 1 sec, 2 sec, 5sec, 10 sec and 20 sec.
Display formats: The analyser incorpo-rates a large LCD display, on which amaximum of 104 data points can be displayed at any time. The number ofparameters to be selected can be 4, 8,16 or all, and the number of parametersand the quantity of data to be displayedcan be arbitrarily combined by the user.
The instrument can display a waveformof an input signal (Figure 5) and thetrends of measured data in a time series(Figure 6). It can also display a list, bargraph, and vector of harmonic waves. In addition, for the first time it can dis-play a waveform during integration.
Communications interfaces: Theanalyser is equipped with a GP-IB interface as standard, while RS232C,Ethernet, and USB interfaces areoptional. For the Ethernet interface, in addition to a control function using the IEEE-488.2 command, an FTP serv-er/client function is also provided.
Measured data can be stored in a PCcard and transferred to a PC using theinterface function. USB communicationenables measured data storage, key-board connection for file name typing,and outputting to the printer.
Applications softwareA number of dedicated PC software
applications are available for use withthe new power analyser:
• WTViewer software: This makes itpossible to read measured numericalvalues and waveform data into the PCvia the communications interfaces, dis-play numerical data and waveforms,and convert them into a specified dataformat and store them.
• LabVIEW driver: A library that can beused with the National InstrumentsLabVIEW software.
ApplicationsThis instrument should find use in manytypes of power measurement applica-tions, ranging from standard powermeasurement and calibration systemsto high-accuracy measurement forinvertors and motors the evaluation of transformers.
This article is based on a paper inYokogawa Technical Report No.39, 2005:http://www.yokogawa.com/rd/TR/rd-tr-o00000-000.htm. Detailed informationon WT3000 power analyser is available athttp://www.yokogawa.com/tm/WT3000/
For inquiries within Europe, please contact Yokogawa Europe BV (TheNetherlands) at [email protected]
www.yokogawa.com
Figure 5. Waveform display. Figure 6. Display of measured data trends.
The argument for higher voltagestems from the reduced currentrequired by all components, and
above all from the reduced cable thickness.This cuts the weight quite enormously,and helps to save space. Additionally,efficiency is improved as a result ofreduced losses at various intermediateresistances.
All components for higher voltagesneed to be newly developed and tested.But it is not only higher voltages thatgive rise to the need for equipment andcomponents testing. Existing systemsneed to be tested following modifica-tions, to ensure their continuing func-tional reliability, for example ABS andairbags. Matters will become even morecritical if and when new drive-by-wirefunctions are introduced, such as steer-by-wire and brake-by-wire, meaning thedriver will control only an electronicpanel and all else, steering, braking,and motor control, will be done electron-ically. This article explains what testsare necessary and how these can becarried out with a power amplifier.
The on-board vehicle network, as a freely floating network, offers by nomeans a clean constant DC voltage. It is a DC voltage with various alternatingvoltages superimposed. These alternat-ing voltage components originate mainly
from the generator and the rapidlychanging loads. Load changes can beresistive, inductive or capacitive. Rapidload changes can therefore lead tosharp voltage drops or even over volt-ages. Thus before putting equipmentinto operational use it is important tocarry out a realistic network simulation.
Certainly there are vehicle networkcomponents which can fail without critical results. But attention must befocussed on the critical components.Most manufacturers do not just rely ongiving recommendations, but havehouse standards which define the limits applying to their specifications.Understandably, a vehicle network sim-ulation must be able to reproduce allconceivable voltage events, extendingfrom over- and under-voltage right up tosudden short circuits.
Vehicle network simulation withpower amplifiers
Power amplifiers are well suited fortesting all possible eventualities in avehicle network. They can generate thevarious voltages and currents requiredto test all components under all the con-ditions that may actually arise. For thispurpose the new PA207X series ofHERO POWER amplifiers is ideallydesigned. The amplifiers are linear reg-ulated power amplifiers, with output volt-
ages that can be repeated as often asdesired, which have been proven asonboard network simulators, either assource or drain. They can be used intesting batteries equally as well as inproviding any desired network voltage.
These network simulators operatefrom 0 to 60V with flank rising andfalling rates of about 8 V/μs at full outputpower. The dynamic internal resistanceis particularly important. In voltage use itis <1 milliohm for DC, and in current useabout 100 kiloOhms for DC. In order toreduce power loss arising at small out-put voltages, over the B2 region from 0to 30V, the output voltage can beswitched in increments. The user canchoose the unit he needs for his powerrange from a range of amplifiers cover-ing different power outputs.
Programmable rangesPower amplifiers must be able to
emulate almost all events that can hap-pen in the real environment. The poweramplifier should be programmableaccordingly (figure 1). A model with thiscapability is the PA2073-82-S amplifier.It has two symmetric and two asymmet-ric (switch able) outputs for currents upto 50A (150A, 200ms), through which itcan be optimally adapted to differentrequirements.
The discussion regarding on-board vehicle voltages, for example 12, 24, or 42V DC, or even AC,for avionics or automotive applications continues vigorously.
By Dipl.-Ing. Helmut K. Rohrer, Rohrer GmbH, Munich
Operation at various on-board vehicle voltages
POWER MEASUREMENT POWER AMPLIFIERS
www.powersystemsdesign.com 39
current output, enabling testing to beperformed with constant voltage or constant current.
For flexible installation the poweramplifier is built into a robust 19-inchmini-rack, with rollers. For operation itneeds to be supplied from a three-phase supply voltage 3 x 400V/50Hz,but can be adapted for every otheroperational voltage as necessary.
For safe operation of components it isindispensable for all conceivable fluctu-ations of an onboard supply to be inves-tigated, so that under all circumstancessafe use is guaranteed. The conse-quences can only be too well imaginedif in a braking manoeuvre the brakes, orwith an aircraft the controls, do not func-tion, or do not function properly, onaccount of an on-board network fluctua-tion. In order to guarantee the highestlevel of operational security, all connec-tions of the power amplifiers (input/out-put/output voltage monitor/output cur-rent monitor) are galvanically isolated.
At the same time accuracies of 0.1%are attained. The power amplifiers aremanufactured in Munich, so that for theuser’s actual application the manufac-turer’s know-how is readily available.Various battery simulators and otherHEROPOWER power amplifiers arealso available for test purposes.
www.rohrer-muenchen.de
38 Power Systems Design Europe January/February 2006
The asymmetric regions +60/-5V and+30/-2V serve for on-board network sim-ulation. In point of fact networks areunipolar positive, but for simulation ofprecise and rapid discharge processes a
negative voltage is necessary. Thisshould be small, to keep the lossesunder load conditions as small as possi-ble. At the same power, the advantageof a higher current is obtained. For other
purposes symmetric outputs are neces-sary, ±50 or ±30V. No other poweramplifier currently offers this multifunc-tional and cost-saving facility. When aload is switched into the network, thevoltage drop will be insignificant; theHERO power amplifier reacts to loadchanges in <1μs, so that virtually novoltage drops occur.
For documentation purposes isolatedmeasurement inputs are offered overthe range ±500V. These are differentialinputs, enabling a real-time signal to becaptured at any desired point. They areavailable for appraisal on a monitor, orto provide indication for example on anoscilloscope. The danger of false con-nection from earthed means of meas-urement is thus excluded. To ensure no difficulties arise with the indication of measured signals, all monitor andmeasurement inputs are floating, so thatsimultaneous potential disturbances canhave no effect.
But not only the measurement inputsare potential free, the entire poweramplifier is built to be potential free, witha common reference potential for inputand output. With galvanic separationbetween input and output, these canhave different reference potentials,enabling earth loops to be avoided.
For investigating various forms ofinterference, the PA2073-82-S poweramplifier has two control inputs for twosignal sources. Both signals are added;for example for harmonic modulation.With the 150 kHz modulation frequency,high frequency interference can be well simulated. For actual testing of theconnected equipment, a continuouslyadjustable current and voltage limitationcan be programmed (without load), inorder to protect the equipment fromoverload and also for protection in faultservicing.
With the help of a pulse generatorwith TTL input, steep switching flankscan be generated, the level of which canbe rapidly changed. With all testing, theoperation mode can be switched fromregulated voltage output to regulated
Figure 1. Operation of the power amplifier is made much easier by an intuitiveinterface, here in conjunction with a 3-phase equipment.
Figure 2. For safe operation, the curve of overload performance must be investi-gated in every case. After 200ms of a 3-phase overcurrent the power amplifierautomatically reverts to the nominal value.
Figure 3. After a rise time of 4μs, the test curve is continuously run through.
POWER AMPLIFIERS POWER AMPLIFIERS
40 Power Systems Design Europe January/February 2006
Variable speed and powerlectronic converter
Contemporary trends of future development in mobile electrical generator sets (EGS) show, thatthe new generation of EGS will be based on new technologies. Constant speed mobile electricalpower sources with combustion engines driving brushless field excited synchronous generatorswill be replaced by optimally controlled variable speed diesel engine, driving robust permanent
magnet generator equipped with power electronics frequency and voltage control.
By Jan Leuchter and Otakar Kurka, University of Defense (Czech Republic)By Pavol Bauer, Delft University of Technology (The Netherlands)
Mobile Electrical Power Sources,initially developed and producedmainly for military purposes,
gradually found their use as power sup-plies for various machines and appliancesto increase their mobility, in mobile work-shops, lighting systems, in communica-tion and control systems. EGS enablethe independence on the common electri-cal power network and create an essen-tial part of Uninterruptible PowerSources. They are used in buildingindustry, in agriculture, in ground and airtransport, in health service and in otherbranches of industry and economy.Quite indispensable are the EGS in civildefense, crisis management forces, andnaturally in armed and security forces.Sophisticated weapon systems, includ-ing aircraft and air defense, artillery sys-tems, transport means, logistical struc-ture and training systems based oncomputer simulation and virtual realityconcepts require also modern and reliableEGS, corresponding to new conditionsand requirements.
Mobile electrical power sources of the 1 and 2nd generation, based onimproved classical engine - generator
sets, are gradually introduced in thecourse of last two decades. These EGSare operating with constant speed corre-sponding to the required fixed frequency(50, 60 or 400 Hz), as shown in Figure2. The 1st generation of EGS (EGSG1)is based mainly on the classical motor-generator principle with a common
electromagnetically excited synchronousgenerator driven by petrol or dieselengine at a constant speed correspon-ding to the required frequency of outputvoltage. EGSG1 are very heavy, difficultto handle, noisy and low efficient.
POWER GENERATION
Figure. 1 Mobile electrical power sources.
www.powersystemsdesign.com 4342 Power Systems Design Europe January/February 2006
engine in the case of sudden power out-put increase requires the time of fewseconds to change the speed of enginefrom the low to higher speed. During thistime, the power required by the load isnot available and diesel engine can byhigh load on the low speed stop undesir-able. The measurement record ofdynamic behavior of EGS with variablespeed is shown in Figure 8. After sud-den change of the load (A), the feed-back control system sets a new opti-
mum speed of diesel engine (B) accord-ing to the characteristic. Delay betweenpower output increase and reaction ofdiesel engine is about 1-5 s in depend-ence on the speed, load (inertia) andcontrol mechanism.
The photo detail of speed control unitof experimental diesel engine HATZ1D40 is shown in Figure 9. The requiredspeed of the engine is adjusted by actu-ating lever and instantaneous speed is
calculated from position sensors, whichmeasure the instantaneous position ofactuating lever. Servo unit is controlledby microprocessor and adjusts requiredspeed by means of actuating lever.
Electronic converter can improve thedynamic behavior of whole EGS systemby means of inserting accumulatedenergy to the DC link (see Figure 10).This concept is based on the delivery ofpeak power from energy storage to the
Figure 4. Fuel economy of EGS with constant and optimumvariable speeds.
Figure 5. The photo of experimental model (1-diesel engine;2-SGPM; 3- AC/DC/AC converter; 4-filter).
Figure 6. The schematic circuit of experimental model with AC/DC/AC converter.
The 2nd generation of EGS (EGSG2)is characterized by using modern dieselengines, new types of generators(brushless, asynchronous, and synchro-nous with permanent magnets) andhigher efficiency than EGSG1.Nevertheless these 2nd generationEGS operate still on the classicalengine-generator concept with constantspeed engine as EGSG1.
The investigations of EGS operationin last years have shown that the majori-ty of sets operate under low load, whichdoes not exceed more than 20 % ofrated permanent load. In these condi-tions both the engine and generatoroperate with low efficiency, affectingunfavorably the pollution and fuel consumption. An optimal control ofengine-generator set speed in thedependence on the instantaneous EGSload (Figure 3) can decrease the fuelconsumption namely at low and middleloads, as shown in Figure 4. The opti-mum speed is hereby calculatedaccording to the EGS load with the opti-mality criterion the minimum fuel con-sumption. The consequence of varyingengine speed both the output voltageand the frequency of the generator are
variable and must be converted to theconstant value required by the load(usually 3 x 400V, 50Hz). Therefore it is necessary to introduce a power elec-tronic voltage and frequency converterto the new EGS structure (EGSG3).
New generation of EGS brings someprimary benefits:
• the fuel consumption savings for lowand middle load;
• decreasing the amount of harmful airand acoustic emissions;
• longer lifetime and higher reliabilityof EGS;
• increasing versatility of output elec-trical parameters EGS (voltage andfrequency);
• increasing of the quality of output energy.
The main handicap of new conceptEGS creates higher initial costs EGSthen EGSG1 and EGSG2. These initialcosts can be higher by 30 % accordingto kind of power electronic converterthat stabilize output voltage and fre-quency. The initial costs will be compen-sated by decreased operating costs.The desire for future EGS is that they beportable, lightweight quiet systems that
are electronically controlled and capableof operating on fuels in extreme environ-mental conditions.
Power Electronics of EGS with optimum variable Speed
The simplified block diagram of EGSwith variable speed of engine wasshown in Figure 3. The photo of 6 kWexperimental EGS consisting of the cho-sen driving Diesel engine, synchronousgenerator with permanent magnets,indirect-type converter (AC/DC/AC), output filter and control speed unit canbe seen in Figure 5. The output voltageof synchronous generator varying in therange of 200 to 400 V at the frequency100 to 300 Hz is to be converted to theconstant value 3x 400 V/ 50 Hz by meansof AC/DC/DC converters (Figure 6).
Synchronous generators with perma-nent magnet without electromagneticexciting system are used in many mod-ern applications with variable speedconcepts. They have high efficiency;high reliability and high speeds can bereached. Variable speeds of diesel enginecorrespond to the output voltage andfrequency of a synchronous generatorwith permanent magnets. Voltage sourcetype converters (AC/DC/AC) are usuallyused on the whole applications range ofpower converters up to a hundred kW ofpower. The function of DC/DC converteris to stabilize the output DC voltage tothe required level of UDC=570V for aninverter output equal to 3x400 V. TheDC/DC converter is designed as STEP-UP chopper (FORWARD) with twoswitches connected in serial with thediode AC/DC rectifier. If the output volt-age of the diode rectifier is less than570 V then the STEP-UP chopperincreases the link voltage (Figure 6).
The output three-phase voltage 400Vof AC/DC/AC converter is adjusted tothe required constant output frequency50 Hz by means of DC/AC converterand the voltage control unit.
The measurements show that the realdrawback of this concept of EGS withvariable speed is the dynamics at sud-den transient from the low load to highload. Dynamic behavior of the driving
Figure 2. Concept EGS with constant speed of engine.
Figure. 3. The concept EGS with optimum variable speeds according load.
POWER GENERATION POWER GENERATION
www.powersystemsdesign.com 4544 Power Systems Design Europe January/February 2006
The RC-IGBT will have a significantimpact on the power module mar-ket due to a more efficient use of
resources such as less silicon, lowerproduction energy and reduced packag-ing materials. Moreover, with thesesemiconductors, Power Control Systemssuch as AC Matrix Converters with noneed for large DC link capacitors comewithin reach.
High Voltage ICs (HVIC) are alreadyused to realize a simple gate drive cir-cuit in the low power area. By employingHVICs, a single gate power supply is
sufficient for driving all six inverter switches.With the transfer-mold package
Mitsubishi has developed a novel mod-ule packaging concept utilizing a newthermal dissipation structure. Thisallows a reduction in package size andweight. Consequently the new packagewill save resources of packaging, logis-tics and energy for transportation.
This new power module, whose keyconcept is “Environmental Compatibility”,will be a combination of RC-IGBT (orRB-IGBT), HVIC and new packagingtechnologies. The Key Word
”Environmental Compatibility” is indicat-ing the new power device’s direction:saving resources.
Environmental Compatibility ConceptThe “ease of use”-strategy is very
important in order to enlarge the marketof power devices. The particular items“Small Size” and “Light Weight” are keypoints in the “ease of use”-strategy.They also contribute to the saving ofresources in packaging, logistics andenergy for transportation. The mostimportant topic today is the reduction ofhazardous substances in order to meet
Transfer-mold packaging technology
With the transfer-mold package Mitsubishi has developed a novel module packaging concept utilizing a new thermal dissipation structure. This allows a reduction in package size
and weight. Consequently the new package will save resources of packaging, logistics and energy for transportation.
By Toru Araki, Mitsubishi Electric Corporation and Robert Wiatr, Mitsubishi Electric Europe
Figure1. New Gate Drive Concept to Reduce Switching Noise.
DC link during the regulation time ofengine from low speed to high speed.For example: the regulation time fromlow speed (1000 rpm-low load) to highspeed (3000 rpm-full load) take about2s and so for 6kW EGS about 12 kJ isrequired. This energy is too high forclassical solution with electrolyte capac-itors. Solution with accumulators canbring enough storage energy butincreases the weight of EGS to unac-
ceptably. Solution of converter withaccumulators brings weight increasingof EGS as much as 60kg.
The optimal way of energy storagecan be achieved by usage of super-capacitors, although they are relativelynew and rather expensive. The efficiencyof charging and discharging is much high-er than in previous solution with accumu-lator and can bring better relationship
between stored energy storage, dimen-sions and weight then accumulators.
The 1st and 2nd generation of EGSoperates with constant engine speedcorresponding to the required outputvoltage frequency. Both engine andgenerator operate often with low effi-ciency at the low and middle load.Higher efficiency and lower operationcosts may be achieved by using newconcept of EGS with optimum variablespeed according to the EGS load. Theoptimum speed is hereby determinedaccording to the EGS load with the mini-mum fuel consumption optimality criteri-on. Both the generator output voltageand frequency are variable and are tobe converted to the constant values bypower electronic converter.
The main handicap of new conceptEGS is higher initial costs EGS thenEGS wish constant speed. These initialcosts can be higher by 30 % accordingto kind of power electronic voltage andfrequency converter. Other drawback ofEGS with variable speed is the engine-generator dynamics at sudden transientfrom low load to high load. Power elec-tronic converter can improve the dynam-ic behavior of whole EGS system bymeans of inserting accumulated energyfrom super-capacitor.
Figure 7. Output voltage and current of EGS.
www.unob.cz/en/
Figure 8. Experimental result of dynamic behavior of EGSG3.
Figure 9. The detail photo of speed control system of EGS.
Figure 10. The EGS system with peak power energy to DC link of AC/DC/AC converter.
http://ee.its.tudelft.nl/epp/
POWER GENERATION POWER MODULES
www.powersystemsdesign.com 4746 Power Systems Design Europe January/February 2006
one single 15V power supply for bothhigh side and low side gate drive func-tion is sufficient.
The integration of the IGBT with gatedrive and protection circuits is stillimportant. This topic is addressed with
the development of an Intelligent PowerDevice (IPD). Figure 4 shows the topview and structure of IPD.
StructureThe small signal conditioning circuits,
which are constructed in CMOS, are
combined with planar IGBTs in this IPD.The combination with CMOS is soimportant, because it facilitates thedesign of the signal conditioning circuits.The gate drive technologies are basedon IC technology, such as the softswitching technology to reduce surgevoltage and EMI noise. HVIC technolo-gy decreases the number of power sup-plies and enables easy usage on cus-tomer side. The gate driver technologiesbecome an important point to realize the“Environmental Compatibility” concept.
Packaging TechnologyOur newest packaging technology is
based on transfer-mold techniques. Thetransfer-mold packaging technology hasoften been used for IC packages. It wasalso used for low power range IPMs, the"Dual-In-Line IPM". Such DIP-IPMs arevery suitable for home appliance use,such as air conditioners, refrigeratorsand washing machines.
Recently the transfer-mold packagingtechnology has also been extended tomiddle and high power applications. Afirst example is the 300A/600V 2in1-package as shown in Figure 5. Figure 6shows the cross-section of a new trans-fer-mold package. A key technical pointis an insulating sheet that is made ofepoxy resin with filler securing a highthermal conductivity. By using a copperheat spreader for a lower thermal resist-ance, the same thermal resistancevalue as with the conventional casetype structure (about 0.1deg/W) can berealized. Furthermore, lead-free solderfor the die bonding is used, so that thepackage is entirely realized without anytrace of lead.
The advantages of these transfer-mold power modules are small size,light weight and longer power cycle life-time. Figure 5 shows a comparison ofthe conventional case type and thetransfer-mold type. By using transfer-mold packaging technology, the weightis reduced to one third, and the volumeto one fifth. This fact exactly complieswith the core idea of “EnvironmentalCompatibility” in middle and high rangepower modules.
Figure 4. Top View and Structure of Intelligent Power Device.
Figure 5: Comparison of Case Type and Transfer Mold Type.
the RoHS directive. By using the newtransfer-mold packaging technology, itwill be simple to realize lead-free pack-ages without additional cost.
Gate Drive TechnologySince EMI noise and surge voltage
issues have become major problems inpower management system design,
gate drive circuits and power chips haverecently reached the same level ofimportance in power modules. Sometimesthe size of noise filters is bigger than theinverter drive system itself. Thereforereducing EMI noise and surge voltage tothe smallest possible values remains auniversally valid request.
Soft switching technology is also away to solve EMI noise and surge voltageproblems. Intelligent Power Modules(IPM) are committed to this. IPMsinclude special gate drive ICs that havea soft switching circuit for EMI noisereduction. Moreover, these have inte-grated protection functions for the powerelements, IGBT and diode. Customerbenefits from IPMs since an easy invert-er system design can be realised withpractically no risk or trouble.
Figure 1 shows the special gate driveconcept for reducing switching noise.The basic concept is that the gate of the IGBT is driven by constant currentinstead of the conventional constantvoltage source. This current value isswitched by the emitter current level ofIGBT that is detected by the sense emitter cell. At turn-on, when the emittercurrent level is low, the gate drive current,and with it the output dV/dt, is small.Hence, the output noise is reduced.When the emitter current reaches halfthe value of the rated IGBT current, thegate current doubles. This currentincrease takes less than 1 s. This veryfast complex operation is realized byhigh speed Bi-CMOS IC technology.
Figure 2 shows the newest gate drivecircuit for the 5th generation IGBT, theCarrier Stored Trench Gate BipolarTransistor (CSTBT). This gate driveremploys soft switching technology toreduce switching noise and a specialsoft turn-off function to decrease thesurge voltage when the CSTBT facesirregular conditions such as over-currentor short-circuit operation. This specialgate driver IC is also made by a highspeed Bi-CMOS wafer process.
The reduced number of power sup-plies for the gate drives is more impor-tant for small power inverter systems,
such as white goods applications wherethe developer aims for the smallest pos-sible inverter system design. For the sin-gle power supply concept, High VoltageIC (HVIC) technology is very useful.
Figure 3 shows a HVIC with bootstrapcircuit consisting of one resistor, diodeand capacitor. By using this topology,
Figure 2. New Gate Drive Conce.
Figure 3. HVIC with Bootstrap Circuit.
POWER MODULES POWER MODULES
www.powersystemsdesign.com 49
NEW PRODUCTS
Tyco Electronics Power Systemsannounced the release of its EQD075Aand EQD020A0F series DC-DC convert-ers, part of a new generation of open-frame DC/DC power modules designedfor UMTS and CDMA base stations andwireless IP routers applications. These
units support a 3:1 input voltage rangethat will allow for operation in both 24V or48V nominal input voltage systems, elimi-nating the need for separate power mod-ules to handle the two input voltageranges, and therefore resulting in signifi-cant cost and logistics savings for OEMcustomers.
EQD075A and EQD02A0F series con-verters operate over a wide input voltagerange of 18 to 60Vdc and provide a singleprecisely regulated output. The EQDseries converters are designed to deliverup to 75W of output power in an industrystandard eighth brick package measuring57.9 mm x 22.8 mm x 8.5 mm (2.28 in. x0.90 in x 0.335 in). The output is isolatedfrom the input, allowing versatile polarityconfigurations and grounding connections.Built in filtering for both input and outputminimizes the need for external filtering.
EQD series converters employ half-bridge conversion topology with highlyoptimized synchronous rectification and
incorporate patented edge-plating withinnovative packaging techniques to deliversuperior thermal performance. EQD075Aoffers a programmable output voltagerange of 3.0V to 5.5Vdc with industrystandard trim equations and can deliver15A at 5Vdc output with full load efficien-cy of 90% (48Vin). EQD020A0F is opti-mized for 3.3V output and can deliver20A at 3.3V with full load efficiency of89% (48Vin).
www.power.tycoelectronics.com
DC-DC Converters Designed for UMTS
48 Power Systems Design Europe January/February 2006
On the other hand, thesame thermal dissipationstructure as for the newtransfer-mold package, i.e.the employment of an insu-lating sheet, is used to opti-mize low power DIP-IPMpackages. This new struc-ture is named “Version 4DIP-IPM”.
Figure 7 shows the trendof DIP-IPM packagingstructures. By using theVersion 4 structure, thethermal resistance willreduce to 60% of conven-
tional full-mold package structures. It isplanned to prepare the Ver. 4 structurefor all package line-ups, such as SIP,super-mini DIP, mini DIP, large DIP, andto cover 3A to 75A current range.
Another direction of future packagetechnology will be the direct lead bondstructure. Figure 8 shows its cross-sec-tion and internal architecture.
The first feature of direct lead bondstructure is increased current density.This results in reduced chip size for theIGBT. The second feature is low resist-ance of the emitter wire thus reducingon-voltage. The third feature is animprovement of power cycling capability.Compared to conventional Al wire bondstructure it has been extended morethan ten times. By using the new trans-fer-mold package technology and directlead bond structure, a higher reliability,lower cost, smaller size and lighterweight for the power module packagecan be realized. All these features con-tribute to the “EnvironmentalCompatibility” concept.
ConclusionMitsubishi’s “Environmental
Compatibility” concept is based on anew power chip, a new gate drive andnew package technologies. The goal isto combine all these technologies tosave resources, energy and time. Thiswill lead to further cost reductions forboth - manufacturers and customers,and will contribute to a further propaga-tion of power control systems.
Figure 6. Cross-Section of the New Transfer Mold Package.
www.mitsubishichips.com
POWER MODULES
Figure 7. Trends in Package Structures of DIP-IPM.
Figure 8. Cross Section and Internal Architecture of Direct Lead Bond.
www.powersystemsdesign.com 5150 Power Systems Design Europe January/February 2006
NEW PRODUCTS
High volume applications adopt pre-cured thermally conductive gap fillers asthe preferred solution
Chomerics T630 and T630G dispen-sable form-in-place gap filling materialsare finding a growing number of applica-tions in high volume automotive andconsumer equipment. With the ability to be applied quickly with excellent
repeatability using automated dispensingequipment, the economical materialsprovide a valuable option for engineerslooking to solve thermal problems inhigh volume applications.
THERM-A-GAP T630 and T630G arefully cured silicone based materials thatenable effective heat transfer betweenelectronic components and the chassisor enclosure wall of a piece of equipment.They can be dispensed directly onto thetarget surface and do not require a post-application curing cycle. This means thatmating components can be assembledimmediately after the application of thematerial; a characteristic that is valuablein high volume, automated production
environments.Being able to achieve 50% deflection
with just one psi of applied pressureallows the material to be used with deli-cate components and in applications wherehigh assembly pressures are difficult orexpensive to achieve. The materials areable to fill gaps ranging from 0.020 inchesto 0.120 inches. An additional benefit ofT630 and T630G is the vibration damp-ening effect they can provide; this isespecially useful in automotive modules.
Both T630 and T630G are UL 94V-0compliant and have an operating tem-perature range of –50°C to +150°C.Shelf life is 18 months.
Chomerics Conductive Gap Fillers
www.chomerics.com
International Rectifier has launched athree-phase PWM control IC with inte-grated drivers for DC-DC converters.The IR3094MPbF enables up to 40%circuit size reduction when used withInternational Rectifier DirectFETMOSFETs. The smaller footprint makesthe IR3094 ideal for space-constrainedapplications like DDR memory in rackservers and point-of-load (POL) mod-ules used in high-density data systems.
A typical 80A, three-phase synchro-
nous buck solution would require asmany as 13 devices including one con-trol and three drivers in addition to threeMOSFETs per phase. A chip set madewith the IR3094 plus IRF6637 andIRF6678 DirectFET MOSFETs reducesthe silicon component count to sevendevices for the same output current.Three pairs of these DirectFET MOSFETscan be placed directly next to the IR3094,creating a solution that minimizes print-ed circuit board trace parasitics andenables optimum switching performance.
The IR3094 is designed for applica-tions requiring a 0.85V to 5.1V output.The new IC is housed in a compact7mm x 7mm MLPQ package, and fea-tures 3A gate drive capability, a 1%accurate reference voltage, adaptivevoltage positioning and programmable
switching frequency up to 540kHz. TheIR3094 provides system protection withprogrammable soft start, hiccup over-current protection, over-voltage protec-tion, and a “power good” indicator.
The IRF6678, an ideal synchronousMOSFET, features a very low typicaldevice on-resistance of 1.7mOhm at10VGS and 2.3mOhm at 4.5VGS. TheIRF6637 is best suited as a controlMOSFET, with very low Miller charge ofonly 4nC and typical device on-resist-ance of 5.7 mOhm at 10VGS and 8.2mOhm at 4.5VGS. Both MOSFETs arehoused in the medium can DirectFETpackage, occupying the same boardarea as a SO-8 with only a 0.7mm pro-file, and improved thermal performancethrough double-sided cooling.
Three Phase PWM with DirectFET
www.irf.com
Texas Instruments announced its firstintegrated battery charge controller witha System Management Bus (SMBus)interface aimed at multi-cell, multi-chem-istry battery packs used in portableapplications.
TI’s highly accurate and power effi-cient bq24721 charge managementdevice easily interfaces to a system’shost controller through an SMBus com-munications interface. The charger offers
0.4 percent accuracy on charge voltageregulation and two percent accuracy oncurrent amplifier outputs. Using a syn-chronous NMOS-NMOS rectifier, theeasy-to-design device can achievepower efficiencies up to 94 percent.
The bq24721 integrates several high-performance features, including the sys-tem power selector function, which auto-matically selects the AC adaptor or thebattery to properly manage the system
load. The device’s dynamic power man-agement (DPM) function controls thecharge current depending on systemload conditions, avoiding AC adaptoroverload. In addition, high accuracy cur-rent sense amplifiers enable accuratemeasurement of either the charge currentor the AC adaptor current, allowing ter-mination of the “non-smart” packs andmonitoring of overall system power.
SMBus Battery Charge IC
www.power.ti.com/battman
LeCroy launches a new line ofWaveRunner digital oscilloscopes thateliminate the tradeoff between highperformance, display size, and benchfootprint.
Like WaveSurfer, these oscilloscopesboast big, bright, 10.4” displays and only
6” (15cm) of depth,making them perfectfor a crowded bench,and great for engi-neers who appreciatea big display to betterunderstand their circuit.The WaveRunneroscilloscopes boast ofsample rates up to 10GS/s (interleaved) onthe 600 MHz unit, andstandard 2 Mpt/Chmemory (with optionalmemory up to 24Mpt/Ch interleaved).
These high sample rates (at least 10Xoversampling) result in significantly bet-ter signal fidelity for fast edges or highfrequency signals, and ensure accuratetiming measurements when using allchannels. In fact, these sample ratesexceed those of most competitive
scopes that are rated at 1 or 1.5 GHzbandwidth (and also have a correspond-ingly higher price). Thus, theWaveRunner Xi Series is the highestperformance oscilloscope in this band-width class with the most desirable formfactor?an unbeatable combination.
In addition, LeCroy offers a mixed-sig-nal option (MS-32) that allows you toadd 32 digital channels, each with 1Mpt/Ch (32 Mpts total) to a 4 channelWaveRunner Xi to expand 4-channelscope capability to 4+32, which signifi-cantly enhances mixed signal andembedded controller debug.
Simply put, the WaveRunner Xi Seriesprovides 2.5-5X the sampling rate, 2Xthe viewing area and half the footprint of any competitive oscilloscope—nocompromises!
LeCroy WaveRunner Xi Series Oscilloscopes
www.lecroy.com/europe
Tektronix announced the introductionof the DPO7000 Digital PhosphorOscilloscopes (DPOs). These break-through instruments are based upon anew generation hardware platform thateliminates the trade-offs found in allother oscilloscopes between samplerate, record length and waveform cap-ture rate. With technology innovation,unmatched features and specifications,the real-time DPO7000 is the world’sfirst uncompromised performance oscilloscope.
Design engineers are increasingly
working with embed-ded systems thatpresent a variety ofchallenges in serialdata, power design,video and other appli-cations. In addition,faster signallingspeeds are becomingmore prominent inmainstream applica-tions. To meet theneeds brought aboutby increasing speedand complexity, engi-
neers need greater real-time signalacquisition and instrument intelligencefor design validation, debugging andcompliance. This requires the fast sam-pling rates, long record length (deepmemory), fast waveform capture andanalysis capabilities uniquely availablein the DPO7000. Ranging from 500MHz to 2.5 GHz, the new DPO7000models are ideal for engineers and technicians wanting to more efficientlydebug their devices, reduce time to market, obtain higher quality productsand lower development costs.
The 500 MHz DPO7054, 1 GHzDPO7104, and 2.5 GHz DPO7254 models share a new generation platformthat makes broad use of IBM 7HP silicongermanium (SiGe) technology to providehigher performance for demandingapplications. The DPO7000 providesfast sample rates of 10 GS/s on fourchannels and real-time oversampling onfour channels; up to 16X oversamplingon one channel and 4X on four channelssimultaneously. The DPO7054 andDPO7104 support 40X oversampling onone channel and 10X on four channelssimultaneously when configured withoption 2SR. The DPO7054 and DPO7104support deep record lengths to 200Mwhile the DPO7254 supports 400M. Allmodels include a 12.1 inch XGA displayenabling engineers to see more infor-mation at once, and all models providevertical accuracy of +/- 1%.
DPO7000 models include the uniquePinpoint trigger system, the world's onlycomplete A/B triggering system to rapid-ly discover and capture intermittent faultsor events in complex signal structures.
Tektronix DPO7000 Oscilloscope Eliminates Trade-Offs
www.tektronix.com
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Companies in this issue
Company Page Company Page Company Page
ABB Lyon . . . . . . . . . . . . . . . . . . . . . . . . .1ABB Switzerland . . . . . . . . . . . . . . . . .1,22Actel . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8Advanced Power Technology . . . . . . .35Anagenesis . . . . . . . . . . . . . . . . . . . . . . .1Ansoft . . . . . . . . . . . . . . . . . . . . . . . . . .11Ansoft . . . . . . . . . . . . . . . . . . . . . . . . . . .1APEC . . . . . . . . . . . . . . . . . . . . . . . . . . .41Artesyn Technologies . . . . . . . . . . . . . . .1Chomerics . . . . . . . . . . . . . . . . . . . . . . .50CT-Concept Technology . . . . . . . . . . .19Danfoss . . . . . . . . . . . . . . . . . . . . . . . .26Danfoss . . . . . . . . . . . . . . . . . . . . . . .1,49EPCOS . . . . . . . . . . . . . . . . . . . . . . . . .31Fairchild Semiconductor . . . . . . . . . .C2Fairchild Semiconductor . . . . . . . . . . . . .1Fuji Electric . . . . . . . . . . . . . . . . . . . . .33
Infineon Technologies . . . . . . . . . . . . . . .1International Rectifier . . . . . . . . . . . . .C4International Rectifier . . . . . . . . . . . . .1,50Intersil . . . . . . . . . . . . . . . . . . . . . . . . .1,10iSuppli . . . . . . . . . . . . . . . . . . . . . . . . . .12Lecroy . . . . . . . . . . . . . . . . . . . . . . . . . .51LEM Components . . . . . . . . . . . . . . . . .3LEM Components . . . . . . . . . . . . . . . . . .1Linear Technology . . . . . . . . . . . . . . . . .5Linear Technology . . . . . . . . . . . . .1,27,52Maxwell . . . . . . . . . . . . . . . . . . . . . . . . . .6Mitsubishi Electric . . . . . . . . . . . . . . . .23Mitsubishi Electric . . . . . . . . . . . . . . . . .45National Semiconductor . . . . . . . .28,29National Semiconductor . . . . . . . . . .1,6,8Ohmite . . . . . . . . . . . . . . . . . . . . . . . . . . .1On Semiconductor . . . . . . . . . . . . . . . .1,4
Pemuk . . . . . . . . . . . . . . . . . . . . . . . . . .35Power Integrations . . . . . . . . . . . . . . . .7Power Integrations . . . . . . . . . . . . . . .1,16Power Systems Design Franchise . .C3Semikron . . . . . . . . . . . . . . . . . . . . . . . . .1Silica . . . . . . . . . . . . . . . . . . . . . . . . . . . .4ST Microelectronics . . . . . . . . . . . . . . . . .6SynQor . . . . . . . . . . . . . . . . . . . . . . . . . .1Tektronix . . . . . . . . . . . . . . . . . . . . . . . .51Texas Instruments . . . . . . . . . . . . . . . .17Texas Instruments . . . . . . . . . . . . . . .1,50Tyco Electronics . . . . . . . . . . . . . . . . .1,49University of Defense . . . . . . . . . . . . . .40Delft University of Technology . . . . . . . .40Wurth . . . . . . . . . . . . . . . . . . . . . . . . . .39Yokogawa . . . . . . . . . . . . . . . . . . . . . . .32Zetex . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Please note: Bold—companies advertising in this issue
Linear Technology announces theLTC3412A, a high efficiency, 4MHz,synchronous buck regulator using aconstant frequency, current mode archi-tecture. It can deliver up to 3A of contin-uous output current at voltages as lowas 0.8V from a 4mm x 4mm QFN (or athermally enhanced TSSOP-16) pack-age. It operates from an input voltage of2.25V to 5.5V, making it ideal for bothsingle cell Li-Ion, or NiMH applications,
as well as more general purpose fixedrail systems. Its 4MHz switching fre-quency allows the utilization of tiny lowcost capacitors and inductors with lessthan 1.5mm profile. High frequencyoperation also keeps switching noiseout of critical wireless and xDSL fre-quency ranges, making it ideal for xDSLmodems, cellular base stations andautomotive applications.
The LTC3412A uses internal switches
with RDS(ON)s of only 0.065 Ohm and0.077 Ohm to deliver efficiencies ashigh as 95%. It also utilizes low dropout100% duty cycle operation to allow out-put voltages equal to VIN. No load qui-escent current is only 64uA, and lessthan1uA in shutdown, making it ideal forapplications such as automotive powersystems that require ultra-low supplycurrents. For optimum efficiency at lightloads, the LTC3412A utilizes selectableBurst Mode® operation to reduce gatecharge losses. The current at which theBurst Mode operation initiates is userprogrammable, enabling the designer to optimize light load efficiency. If theapplication is noise sensitive, theSYNC/MODE pin can also be config-ured to provide forced continuous oper-ation to reduce noise and RF interfer-ence. Additional features include aPower Good voltage monitor, externalsynchronization capability, and thermalprotection. The LTC3412A is an ideal,for applications requiring 3A of outputcurrent, and where a small solution sizeand low supply current are critical.
www.linear.com
4MHz, Synchronous Step-Down Regulator
