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CONTENTS
ViewpointCalifornia Power Dream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Industry NewsC&D Technologies European Distribution Account Manager . . . . . . . . . . . . . . . . . . . . .4
Sales Manager for Artesyn’s Power Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Analog Devices Celebrates 20th Anniversary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Ericsson Signs Distribution Agreements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Rutronik Announces New Franchising Partner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Micrel Announces Sub-Micron 0.35 Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
10A DC/DC uModule Provides New Level of Power Density in a Compact Package . . .8
The Role of Power Semiconductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
MarketwatchEuropean and Japanese Power Semis Face Currency Challenges . . . . . . . . . . . . .12
Cover StoryModular Inverters for High Power Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Industrial ElectronicsAmplifier ICs Driving Piezo Electric Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Fast Body Diode MOSFET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Lamp Ballast Design with Less Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Applying Thermal Simulation Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Integration Streamlines Industrial Motor Control Design . . . . . . . . . . . . . . . . . . . . . . .40
Unwinding the Mysteries of Switching Transformer Design . . . . . . . . . . . . . . . . . . . . .44
New Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51-56
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 TechnologyRüdiger 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 October 2005
Fall is good for Europeans to take off a fewdays and watch the Ocean in California. Thistime I watched the Pacific and learned moreabout the Power of Mother Nature.
Solar Farms and Wind Farms are an answerto generate green power and help to conserveour natural resources. Driving the pacific coastup to San Francisco you can see wind powerat work with the many wind mills, too many to count.
The solar farm in the desert region is another example of green power. The demand ofpower is the one side, the efficient generationand the minimizing of losses is on the otherside, the challenge for the engineers.
The semiconductor technology makes it hap-pen that solar cells have been developed andoperate more and more efficient over time.
The MOSFET is the switch to handle thevoltage and current levels for solar cells.Converters are needed to get the sinusoidalline voltage generated. Here is the IGBT readyto play its game at the mains.
The windmill generates sinusoidal current athigher voltage therefore the switches are IGBTmodules to do the job. The driver IC technolo-gy is the complimentary part to have thedevices optimized in their switching perform-ance. All together it is power management thatmakes it the efficient solution for us.
In our October issue you will see Semikrontelling us about IGBT modules and their appli-cations. The industrial aspect of power semi-conductors is a large market in Europe. IR tellsus about motion applications. Fairchild and aswell Infineon covers optimization of efficientfluorescent lamps. Not to underestimate todaythe simulation of thermal conditions as the die shrinks and but still carries the same current or more. All of it is important for indus-trial applications.
Mother nature has shown us our limits withhurricane Katrina, APEC 2006 has now movedfrom New Orleans to be in Dallas, Texas.
Looking forward to seeing you at the upcom-ing shows, SPS in Nuremberg, Productronicain Munich and APEC in Dallas.
Best regards,
Bodo ArltEditorial DirectorThe Power Systems Design Franchise
California Power DreamAGS Media Group
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Volume 2, Issue 8
VIEWPOINT
4 Power Systems Design Europe October 2005
INDUSTRY NEWS
C & D Technologies European Distribution Account Manager
C&D Technologies
has further
strengthened its
distribution team
with the appoint-
ment of Mark
Hillier as distribu-
tion account man-
ager for the com-
pany’s Power
Electronics Division.
Based at the Power Electronics Division’s
European headquarters in Milton Keynes in
the UK, Mark will work within the EMEA
(Europe, the Middle East, and Africa) group,
where he will have responsibility for selected
European distributors.
Mark brings a wealth of experience in the
electronics industry to C&D Technologies,
having previously worked in component sales
for both IBM and NEC.
The Power Electronics Division of C&D
Technologies, Inc. has its headquarters in
Tucson, Arizona, USA, with manufacturing in
USA, Mexico, UK and China plus sales loca-
tions in the USA, UK, France, Germany,
China and Japan. The division designs, man-
ufactures and distributes DC/DC converters,
AC/DC power supplies and magnetics, and
offers these products in custom, standard
and modified-standard variations. These
products, which are built to exacting require-
ments in ISO9000:2000-approved facilities,
are typically used worldwide by Original
Equipment Manufacturers (OEMs) within
telecommunications, computing, industrial
and other high-tech applications.
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
ArtesynTechnologiesannounced theappointment ofRobert Sobingeras EMEA RegionalSales Manager forthe company'sPower Conversiondivision. He willassume immediateresponsibility for
sales of all standard power conversion prod-ucts in Central and Eastern Europe, theMiddle East and Africa.
Mr. Sobinger has a solid background inelectronics, including more than 13 years'experience of the power conversion industry.Immediately prior to joining Artesyn he wasDirector of Sales for the specialist Germanelectronics distributor, Fortec Elektronik AG,whose key product lines include Astec ac-dcpower supplies and dc-dc converters.Sobinger has also worked for Astec directly,holding various senior management positionsin engineering and sales support during his9-year tenure with the company.
“We are extremely pleased that Roberthas joined our sales team”, says StephenNolan, Artesyn's VP of Worldwide Sales for
Standard Products. “His power background,combined with his customer and distributorknowledge, will prove to be key assets inhelping us to grow market share, especiallyin central Europe. Robert is also renownedfor his leadership qualities, and I know thatour distributors will welcome having a strongchampion to their cause.”
Sales Manager for Artesyn's Power Conversion
Analog Devices today celebrated the 20thanniversary of its office in Vienna, Austria,and of the successful operation in EasternEurope and Russia that has been managedfrom this location.
Analog Devices’ office in Vienna wasopened in August 1985 by Walter Raiger,who continues today as the general directorfor Austria and Eastern Europe. In 1987, theAustrian team started working with customersin Hungary and the former Yugoslavia. Twoyears later, Analog Devices expanded itsactivities into Russia, and participated in itsfirst electronics show in Moscow in September1989. Since then, the company has steadilyexpanded its presence and grown its salesthroughout the region.
“Throughout the last two decades, ADI’ssuccessful strategy in Eastern Europe hasbeen based around innovative customers,close links with local distributors, and a loyaland hard-working team,” said Thomas Wessel,Managing Director for European Sales andMarketing, Analog Devices. “I congratulateWalter Raiger and his entire team on reach-ing this 20th anniversary milestone.”
Today, the region spans 25 countries with direct sales and a strong presence of distributors.
The biggest industry sector for AnalogDevices in Eastern Europe is industrial andinstrumentation (I&I). I&I applications designedby Eastern European and Russia customersinclude power, heat- and flow-meters in addi-
tion to industrial controllers. The consumerand communications markets have alsoexperienced considerable growth with astrong focus on the development of telephoneexchange systems and the automotive seg-ment is becoming increasingly important.
Analog Devices Celebrates 20th Anniversary
www.analog.com
www.artesyn.com
6 Power Systems Design Europe October 2005
INDUSTRY NEWS
Power Events
• SPS/IPC/DRIVES, Nov. 22 - 24, Nuremberg,
www.mesago.de/sps
• PRODUCTRONICA, Nov.15 - 18, Munich
www.productronica.com
• New location and date to note!
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
Micrel announced it has achieved a majormilestone towards implementing sub-micron0.35 technology processing in its world classfab facility located in San Jose California. Withthe purchase of specialized equipment,Micrel’s fab can now run more advanced sub-micron 0.35 CMOS processes. The new toolenables the fab to run sub-micron 0.35 tech-nology in full production mode. This milestoneeffectively takes the fab technology from 0.5 tosub-micron 0.35 capability.
“We are excited about this new equipment,not just for its sub-micron 0.35 capability, butalso because of the increased demand we areseeing from customers for our sub-micron 0.5production,” noted Guy Gandenberger, vicepresident of wafer fab and foundry operations,Micrel. “Not only were we able to secure thissophisticated piece of equipment at a signifi-cantly reduced cost, but we will also add muchneeded capacity at the sub-micron 0.5 level, toinsure that we continue to meet world classstandards for customer service.”
Micrel’s San Jose California-based waferfabrication facility has been certified toISO14001:1996, the InternationalEnvironmental Management System Standard.The Company continues to focus on continu-ously improving its quality, safety and environ-mental practices and, to that end, was recentlyable to significantly reduce water and energyconsumption, saving significant operatingfunds while continuing to preserve the environ-ment. To ensure compliance with the Europeandirective on the restriction of use of hazardoussubstances (ROHS) and other similar regula-tions, the vast majority of Micrel products maynow be ordered in lead-free versions.
Micrel Announces Sub-Micron 0.35 Capability
www.micrel.com
As part of its program to strengthen localsupport, gain a closer understanding of cus-tomers’ culture and language, and as part of its ongoing strategy to achieve the highest lev-els of communication and service, Ericsson Power Modules has signed distribution agree-ments with European distributors UltimateRenaissance and the French power expert BM Energie.
Under the agreements, UltimateRenaissance will support Ericsson PowerModules’ sales in Italy, France and Spain,
serving global customers and expandingdemand creation in many of the market seg-ments addressed by EPM’s products portfolio,while, by its specificity BM Energie will supportindustrial and computerized applications, with-out excluding demand creation in other busi-ness areas.
“By the nature of the industry in SouthernEurope, and the extension of Ericsson PowerModules’ portfolio to Intermediate BusArchitectures and its strong development of abroad range of POL (Point Of Load) products,
both distributors will contribute to increase the level of support to all of Ericsson PowerModules’ customers moving forward on thenext generation of power management.” SaidPatrick Le Fèvre, Marketing Director at EricssonPower modules. “It is exciting to be to movingforwards with Ultimate Renaissance and BMEnergie and I feel very confident that our cus-tomers will appreciate their expertise and longterm investment in the power industry.”
Ericsson Signs Distribution Agreements
www.ericsson.com/powermodules
Rutronik has augmented its franchises in theelectromechanics sector throughout Europewith leading manufacturers. The franchises willbe expanded with Panasonic, Fujitsu andComus to all Europe. In the batteries segment,Rutronik is cooperating with BMZ, one of thelargest manufacturers of battery packs, also ona European level. The franchise for Panasonicbatteries will be expanded from Germany toinclude Scandinavia, Benelux, Switzerland,Austria and Eastern Europe. The connectormanufacturer FCI (until now only a partner in
France) has expanded its franchise agreementwith Rutronik to include Scandinavia andEastern Europe. The long-standing successfulcooperation with Molex in Germany and Francewas the decisive factor for expanding the fran-chise area to include Austria and EasternEurope. Further connector manufacturers, suchas ITW Pancon, expand the connector portfolioacross Europe. For Odu, Rutronik will be oper-ating with immediate effect in Scandinavia. Theswitches segment has been expanded with theEuropean franchise for Diptronic products. For
Rutronik, this step means a further expansionin the electromechanical business sector and a virtually pan-European harmonisation of itsproduct portfolio for connectors, relays, batter-ies, fuses and switches. With this franchise situ-ation Rutronik is becoming a leader for electro-mechanical products in Europe. The focus willmainly be on the automotive, mechanical engi-neering, medical technology and consumerelectronics market segments.
Rutronik Announces New Franchising Partner
www.rutronik.com
8 Power Systems Design Europe October 2005
Anew uModule™ (micro-module)from Linear TechnologyCorporation provides designers a
complete 10A switching power supply ina tiny (15mm x 15mm) footprint, lowprofile (2.8mm) land grid array (LGA)package. The LTM®4600 is a synchro-nous switchmode DC/DC step-downregulator with built-in inductor, support-ing power components and compensa-tion circuitry. The LTM4600 is the first ina new family of uModules from LinearTechnology that leverages the compa-ny’s core strengths in power manage-ment and conversion. By simplifyingpower system development, this newhigh-density power supply reducesdevelopment time for a broad range of systems, including network routers,blade servers, cellular basestations,medical diagnostic equipment, testinstrumentation and RAID systems.
The LTM4600 accommodates a wideinput voltage range of 4.5V to 28V. Thehigh level of integration and synchro-nous current mode operation allows theLTM4600 to deliver superior transientresponse and up to 10A continuous cur-rent (14A peak) at up to 92% efficiency.It simplifies power supply design andconstruction, requiring only input andoutput bulk capacitors and a singleresistor to set the output voltage within a range of 0.6V to 5V. Containing allLinear Technology silicon and supportedby Linear Technology’s rigorous in-house testing and high reliabilityprocesses, the LTM4600 brings compo-nent-level reliability and industry-leadingperformance to demanding applications.
The LTM4600 DC/DC uModule is acomplete stand-alone surface-mountpower supply that can be handled andassembled like a standard integratedcircuit. Moreover, its low profile designpermits the LTM4600 to be solderedonto the back side of a circuit board,freeing up valuable board space.
The LTM4600 DC/DC uModules areself-protected against overvoltage andshort circuit conditions. The devices’ fasttransient response minimizes requiredbulk output capacitance. Furthermore, twoLTM4600s can be operated in parallel,increasing load current capability to 20A.The LTM4600 is offered in two versions:standard and high input voltage. TheLTM4600EV operates from 4.5V to 20V,whereas the LTM4600HVEV has anoperating voltage range from 4.5V to 28V.
Pricing for the LTM4600EV starts at$16.50 each and the LTM4600HVEVstarts at $19.50 each in 1,000-piecequantities. The LTM4600IV andLTM4600HVIV, which are tested and
guaranteed to operate over the -40°C to85°C temperature range, are also avail-able. The device is currently samplingand the company is accepting volumeorders this quarter.
Summary of Features: LTM4600• A Complete Switchmode Power
Supply with Integrated Inductor &Power Components
• 10A Continuous, 14A Peak OutputCurrent
• 15mm x 15mm x 2.8mm Land GridArray (LGA) Package
• Wide Input Voltage Range of 4.5V to20V (up to 28V for HV version)
• Output Voltages down to 0.6V• Pb-free and RoHS compliant• Current Mode Control• Fast Transient Response• Synchronous Rectification for up to
92% Efficiency• Short Circuit and Overvoltage
Protected
www.linear.com
First in a New Line of Module Products
10 Power Systems Design Europe October 2005
Doing more with less - a greenpaper on energy efficiency issuedby the Directorate-General for
Energy & Transport of the EU commis-sion, states that in 2005 the world willconsume approximately 1,725 Mtoe(Megatons of oil equivalent). Accordingto experts, oil reserves are only enoughto cover today’s needs for about 40years! Combined with the increasingdemand in particular from China andIndia to power growth and to improvethe standard of living for their citizens,there is an energy crisis looming overour heads. In 2002, buildings (residen-tial & tertiary) consumed about 40% ofthe energy with industry and transportaccounting for the remaining 60%(approx. 30% each). Electricity constitut-ed about 20% of the energy demand.
Here comes the role of power elec-tronics and in particular, power semicon-ductors in play. Be it the use of state-of-the-art LTT (Light Triggered Thyristor) inpower generation/distribution systems,super-junction MOSFETs in consumer andcomputing electronics, or Silicon CarbideSchottky’s in power conversion systemsbased on renewable energy sources(solar converters); Infineon together withit’s customers are one-step ahead !
Electricity used in stand-by mode canreach between 5% to 10% of total ener-gy consumption in the residential sector.CoolSET F3 devices incorporatingCoolMOS can help reduce this. Thermalefficiency can also be increased by useof induction cooking methodology ascompared to electric stoves or gasovens – even cooking in a much fasterand efficient manner, using inverterbased technology. Reverse-ConductingIGBTs (Insulated Gate Bipolar Transistor)are specially optimized to suite thisapplication. Recently it was demonstrat-ed that using thinQ diodes (SiC based)
in combination with CoolMOS CSseries, up to 99% efficiency could bereached in the PFC stage for a 1,500Wpower supply. As standard semiconduc-tor fabrication techniques can be utilizedin the manufacture of the above tech-nologies, outstanding performance-costtrade-offs can be achieved.
An energy-saving bulb uses five timesless power than a standard one.Estimates show that replacing bulbs cansave up to _100 annually for a house-hold. Digital control of power conversionis the next step. By implementing asym-metric regulation loops, highly effectiveand faster transient responses can beachieved and capacitors in the output fil-ter saved. One such example is the useof lamp ballast controller ICB1FL01G.
Pumps, fans and compressors are tra-ditionally controlled by valves while themotor is constantly running at ratedspeed, resulting in high power losses.Or they are using smaller, inefficientengines operated intermittently like inrefrigerators or other small HVAC’s. It isestimated that about 15 large electricitypower stations are needed to fuel all thefridges of Europe. With installation ofVSD (variable speed drives) a great
amount of energy can be saved. Use ofnew trench-based field-stop IGBT3 incombination with EmCON (emitter-con-trolled) diodes enhances that further.Conduction and switching losses consti-tute for most of the losses occurringwithin these power semiconductors.Reduction in chip thickness especiallyfor power switches (diodes & transis-tors) enhances the electrical and ther-mal performance of these devices fur-ther, resulting in compact systems atreduced system costs.
90% of energy used in 2002 by thetransport sector in EU came from oil.Increasing oil prices combined with envi-ronmental concerns necessitate themove towards Hybrid Electric Vehicles(HEV). Once again, to have the highestpossible efficiency, use of highly opti-mized IGBTs in combination with low-loss diodes (SiC based potentially) is apossibility. HEVs are gaining share andestimations are that in the next 5 to10years a significant portion of the newcars manufactured will be HEVs.
In 2001, California faced a majorenergy crisis. To address this crisis, itlaunched a public information campaignand reduced energy use by more than6%. With additional policies, it is expect-ed that in the residential sector (EU-15)we could not only limit, but actually evenconsume less in 2010 (333TWh/y), thanwhat we did in 2003 (378 TWh/y).
We congratulate and thank our cus-tomers for having taken together with usthe first steps, towards making use ofenergy in a more efficient manner. Thisis clearly evident not only by the increasein market share of Infineon but alsomaintaining the number-1 position infield of Power Semiconductors in 2004,as reported by IMS.
www.infineon.com
By Arunjai Mittal, VP & GM, Power Management & Drives business unit Infineon
www.powersystemsdesign.com 1312
But can market share losses be entirely attributed to exchange rates?
By Chris Ambarian, Senior Analyst, iSuppli Corporation
The last few years have been greatfor power-management semicon-ductor suppliers—but only for
those based in North America. ForEuropean and Japanese makers of ICsand discrete components that are usedfor the conversion and management ofpower, recent years have brought arapid decline in market share relative totheir North-American competitors.
During the period from 2003 to 2005,North American-based power-manage-ment semiconductor suppliers areexpected to gain 6 percentage points ofmarket share compared to companiesheadquartered in other regions. This will
give the North-American suppliers a 49percent share of worldwide market rev-
enue by the end of this year, iSuppliCorp. predicts. In contrast, Japanesesuppliers during the same period willhave lost between 4 and 5 percentagepoints of share, and European supplierswill cede 1 to 2 points.
Figure 1 presents market share forpower-management semiconductor sup-pliers based in different regions of theworld, using U.S. dollars as a baseline.
One of the major factors behind theregional market-share realignment is adramatic swing in currency exchangerates for the U.S. dollar, the Europeaneuro and the Japanese yen.
As presented in Figure 2, the yen dur-ing the last 11 quarters has gained invalue compared to the dollar, peakingwith a 12 percent surge in the first quar-ter of this year. Although the rise beganto reverse itself in the second and thirdquarters, the yen remained nearly 6 per-cent higher than it was in first quarter of2003. All other factors being equal, astronger yen means that a pricecharged by a Japanese supplier in yenis not as competitive as a price chargedby a U.S. supplier in dollars.
Even worse, the Euro gained a whop-ping 18.2 percent in value versus thedollar up until the first quarter of 2005,before retreating to a degree during thesecond and third quarters. However, theeuro remains nearly 12 percent highercompared to the dollar than it was in thefirst quarter of 2003.
Such dramatic swings in exchangerates can have an effect on global busi-nesses, and certainly large fluctuationssuch as these can be expected to have
MARKETWATCH
Power Systems Design Europe October 2005
an impact. To make matters worse forthe European and Japanese suppliers,iSuppli measures market share on aU.S. dollar basis.
If the shift in currency is accountedfor, and we measure based on somecompromise value, we can see that theNorth American suppliers effectivelygained even more than the 6 percent-age points mentioned earlier—probablycloser to 8 points. In an industry thatnormally sees regional market-sharefluctuations measured in tenths ofa percentage point, these shiftscome as a real shock to the system.
If the whole of the power-man-agement semiconductor marketconsisted of commodity parts,then these shifts could be attribut-able largely to exchange ratemovements. In a typical powerapplication, pennies count—soeven small shifts in currency valuecan make a big difference. Thus, if power-management were com-pletely a commodity market, aEuropean or Japanese suppliermight reasonably anticipate that itsshare of sales will be restoredonce it attains a more favorableexchange rate.
However, nearly half of thepower-management semiconduc-tor market consists of non-com-modity products. This raises aquestion: Is the recent shift in mar-ket share purely a result ofexchange-rate fluctuations—or issome other factor also at play here?
This analyst believes that thereare other issues involved that arerelated to competitiveness—issuesthat will persist even if exchangerates return to previous levels. Itwould behoove the managementteams of European and Japanesepower-management semiconduc-tor suppliers to take a serious lookat their competitiveness, beyondcost and exchange rates.
Both the European andJapanese suppliers have excellentbase technologies from which to
work. However, it appears that whatNorth American suppliers are doing wellat the moment—or perhaps what theyare doing a higher percentage of thetime—is applying new technologiescost-effectively in end products.
Of course, there are success storiesin all three regions, so there are excep-tions to this observation. But on balance,it appears that a disproportionate amountof innovation—not to mention loud mar-keting—is being generated by the North
American suppliers, and the marketshare numbers are telling the story.
Hopefully, the response from Europeand Japan will be renewed vigor, inno-vative ideas and greater value deliveredto the power-management semiconductorcustomer. The customer almost alwaysbenefits from healthy competition and abalanced supply base.
MARKETWATCH
Source: iSuppli Corp. Power Management Service October 2005
Source: World Semiconductor Trade Statistics
www.iSuppli.com
14 Power Systems Design Europe October 2005
COVER STORY
High power configurations to offerratings from 320 to 1550A
Modular power systems must offer user benefits in terms of shorter lead times and lower costs.
The modular SEMIKUB B6CI is a compact, easy to maintain and flexible system for forced
air-cooled inverters from 300A up to 1550A.
By Paul Newman, Managing Director Semikron United Kingdom
Built around the latest IGBT tech-nology for industrial modules bySemikron, this inverter/converter
platform is also the result of 45 years ofexperience which Semikron has in thepower stack business. A global networkof solution centres provides worldwidesupport for local service with develop-ment and production capabilities as closeas possible to the customers’ market.
Designers of many high-power sys-tems, particularly in developing marketsectors such as distributed power gen-eration, often act as systems integratorsand in some cases may not have inter-est in the detailed knowledge of powerelectronics. The speed of developmentof silicon makes it necessary to adapt all interfacing components, such asheatsinks, drivers, capacitors, snubbers
and busbars. These designers need reli-able system building blocks to servetheir power needs, but they also needversatile solutions, which can best beprovided by a modular approach. Modularpower systems can also offer user benefits in terms of shorter lead timesand lower costs.
Semikron has used modular tech-niques to develop SEMIKUBE – aninverter/converter platform for applica-tions up to 900kW with forced-air cool-ing. The modular approach reduces the design time and simplifies on-siteinstallation. It also reduces the spacerequired for spares storage, because asmall number of standard parts can bekept in stock and used in various config-urations as required. The new platformcan accommodate cubes in compact or high-power configurations to offer ratings from 320 to 1550A. In the high-power configuration, a system fan isattached to each module, thus eliminat-ing “thermal stacking” effects by provid-ing a flow of ambient-temperature air to each module in the system. Thisapproach offers a power/volume ratiopreviously only available from water-cooled systems.
Figure 2. Model ratings of the SEMIKUBE range.
Figure 1. SEMIKUBE range.
16 www.powersystemsdesign.com
COVER STORY
A SEMIKUBE usually comprises one,two or three cubes, each of which con-tains two, three or four blocks. Eachblock can contain diodes, thyristors ortwo half-bridge IGBT modules mountedon a high-performance, purpose-designedheatsink. A cube also incorporates itsown bank of capacitors, which is sepa-rately fan-cooled to reduce size andmaximise reliability. By using different
component blocks, a range of currentratings can be offered.
A purpose-designed, optimised driver,based on Semikron’s SKYPER 32 PROcore driver, is incorporated into eachcube. All functions and protection ofSKYPER 32 PRO such as soft turn-offand external error input are maintained.The driver for each cube operates inde-
pendently, but has a common user inter-face, which is accessible from the out-side of the SEMIKUBE unit. Each driveris controlled by the user’s applicationcontroller and provides all necessaryprotection and monitoring features,including galvanic isolation, a safe extralow voltage (SELV) interface, tempera-ture monitoring, short-circuit protection,current and DC voltage scaling and
current balancing. In addition, for main-tenance purpose, a set of LEDs hasbeen added to detail the last faultdetected by the driver. This is certainlyhelpful for the diagnosis and explanationof unattended shut down of the inverter.
Each block incorporates a high-speed,hall-effect current sensor. The monitor-ing of current balance between the mod-ules is achieved by multiple current sen-sors whose signals are individuallymeasured and compared. Any over-cur-rent or current imbalance would lead tothe driver interrupting IGBT gate drivesignals thus providing enhanced protec-tion for the system. This principle offerstriple protection against over currents:
• fast short-circuit via VceSat monitoring
• slow short circuit via current monitoring
• internal short circuit via currentimbalance monitoring
Such a high level of protection guar-antees a safe and reliable operation.
Blocks are interconnected by a modu-lar, co-planar busbar system. This inter-connection block achieves, in a coupleof turns of a screw, a reliable and lowinductive connection between the vari-ous DC blocks. SEMIKUBE™’s powerconnection system (patent applied for) is very easy to dismount and routes DCpolarities together to reduce inductanceand, therefore, oscillating currents. Thisresults in improving the lifetime of thecapacitors. In addition, the electricalconnection is achieved by a system ofspring bands to compensate the effectsof thermal expansion, which guaranteesa constant and long lasting connection.This configuration offers rapid and ver-
satile assembly. The connection can bemade from any side of each block,therefore many mechanical and electri-cal configurations are possible to suitalmost any possible requirement in thestated power range.
The higher power ranges of the SEMI-KUBE system requires up to 8 individualhalf-bridge IGBT modules to be connectedin parallel. Paralleling without de-ratingis a must for efficient design; thereforenovel DC and AC connecting busbarshave been developed. The AC busbarutilises electrically symmetrical, tin plat-ed copper designs.
These busbars are designed such that they have the same resistance andinductance between the load’s connec-tion and each module’s AC terminal.The DC connecting busbars have againbeen designed for low inductance andallow interconnection between DC termi-nals for each and every variant in theSEMIKUBE range.
A single cube can be used in a stand-alone application rated between 320and 390 A, including the rectifier and theinverter. If more power is required, twocubes can be connected in two differentlayouts: one that uses a single systemfan to save space or one that uses twosystem fans to maximise current han-dling. Ratings for these configurationsrange from 520 to 770A. Similarly, threecubes can be arranged in either of theseformations, with one or three systemfans, to offer current ratings from 830 to1550A. Another arrangement is alsopossible, featuring three inverter cubes,plus a fourth cube containing a rectifierand additional capacitance. This config-
uration uses two system fans, providingthe best of all worlds in terms of sizeand current handling. In fact, the systemplatform can accommodate any numberof cubes, offering a very high degree ofversatility, scalability and configurability.
The SEMIKUBE system allows verycompact inverters, converters and othertopologies to be constructed. The cubesthemselves are small and, in addition,clever design of the interconnect bus-bars allows three cubes to be mountedvery close to each other. Off-the-shelfcubes and off-the-shelf platforms allowrapid assembly of a very wide range of solutions.
The SEMIKUBE design, with its highstandardisation of parts allows for easyadaptation to many different topologies.Even though some standard configura-tions are proposed, there are no limits to the combination of possible arrange-ments. Four quadrant inverters, singlephase inverters, diode rectifiers withbrake choppers, polypropylene or elec-trolytic capacitors, all of these variantscan be included in the design to give the most optimized solution.
In the standard, converter/inverterSEMIKUBE, the following componentparts are employed:
The rectifier section can be configuredwith the following topologies; uncontrolled(B6U), half-controlled (B6HK) and con-trolled (B6C). The semiconductor devicesused are the latest IGBT generation of
Figure 3. SKYPER 32 PRO core driver is incorporated intoeach cube.
Figure 4. An inside view of SEMIKUBE 1,2 und 3.
COVER STORY
Power Systems Design Europe October 2005
Figure 5. Horizontal arrangement of SEMIKUBE.
Figure 6. SEMIKUBE Size 1.
17
Power Systems Design Europe October 2005
SEMIPACK® 1600V isolated (3kVac)modules, incorporating the provenruggedness and thermally efficientcopper base plate technology. Inaddition to trigger modules, RC snub-bers are standard and line fusesoptional. The input voltage should bein the range 380 to 500Vac (-15%/+10%), 45 to 66Hz. The maximumrectified DC voltage is 707V.
The DC link capacitors fitted asstandard, are long-life, electrolytic,screw terminal types. The typesselected have been chosen for cost-effectiveness, without compromisingperformance and longevity. The sizingof the capacitors is decided by thenominal current of the inverter andwill have an operating life timeexpectancy (LOP) > 60kHrs. The DCworking voltage is carefully chosen toallow for sudden IGBT switch off whichwould result in a significant rise in DClink voltage. The capacitor bank ishoused in the top half of a very robustframe for easy handling and mechan-ical protection. The top half of thisframe, containing the capacitor bankis seated into its corresponding lowerhalf of the SEMIKUBE frame, whichhas slotted fixing points. This allows,where volumes make it a cost-effec-tive option, the top half to be lifted toaccommodate larger capacitors with-out changing any other aspects ofthe mechanical design. The lowerhalf of the SEMIKUBE frame is fixedfirmly to the heatsink.
The heatsink used in all SEMIKUBEdesigns are highly efficient types butpresent a relatively high air pressuredrop. Consequently, a high pressurecentrifugal type fan is employed. Thefan is a 230V, 50/60Hz type withnoise levels that do not exceed72dBA. Thermoswitch protection isincorporated and the fans have zeromaintenance, long life bearings.Centrifugal fans may also be fitted tothe capacitor bank frame as an option.
The inverter topology is a standardthree phase (B6CI) and uses the latest 1200V soft punch through(SPT) silicon in the proven, costeffective SEMITRANS dual (half
bridge) IGBT modules. SPT siliconoffers efficient operation across a widerange of switching frequencies (up to20kHz) with typical combined switchinglosses around 21mJ (@125°C, per100A). The conduction losses are alsolow, being typically 2.0V @ 25°C. Thestandard inverter is optimised for aswitching frequency of 3kHz, giving asystem efficiency (conduction losses +switching losses + fan losses) of around98%. The gate charge required forthese IGBT modules is typically 1uC(VGE -8/+15V 100A) which is easilyaccommodated by the new SKYPER 32gate drivers employed.
By using common diode, thyristor orIGBT modules, capacitors, heatsinks,fans, bus-busbars and current sensorsacross the range, Semikron can offershort lead times and easy maintenancewith a reduced reference list of spares.All component parts of the SEMIKUBEsystem are fully qualified in areas suchas temperature, humidity, EMC andsafety. SEMIKUBE has been designedwith the RoHS directive in mind.
SEMIKUBE has been developed formedium-sized customers for whom thebenefits of an off-the-shelf, fully expand-able, completely tested and characterisedproduct is very attractive. In marketssuch as motor drives, solar inverters,wind-related power generation, uninter-ruptible power supplies and fuel cells,these new units offer designers thewidest range of off-the-shelf power blocksin the industry. Because the componentblocks can be manufactured in high vol-umes to meet many different medium-volume applications, prices are verycompetitive. Users will have the benefitof a single user interface across therange, the only difference for differentpower levels will be the number of boxes.
Semikron International SolutionsCentres are located in Australia, Brazil,France, India, Korea, Slovenia, SouthAfrica, the United Kingdom and theUSA. The network designs, developsand manufactures custom powerassemblies for a wide range of markets.
www.semikron.com
22 Power Systems Design Europe October 2005
INDUSTRIAL ELECTRONICS
Piezoelectric actuators require high voltage drivers delivering hundred of volts, peak-to-peak,
and since a typical actuator looks like virtually a pure capacitance to the driving amplifier,
almost all the power dissipation becomes the burden of the driving amplifier.
By Sam Robinson, Senior Applications Engineer, Apex Microtechnology Corporation
Industrial and medical are the applications
Across the industrial and medicalmarkets, piezo electric devicesare gaining great favor with design
engineers when their applications requirethe generation of very fine movement.The unique electro-mechanical proper-ties of piezo ceramic materials are prizedfor their ability to perform the finest oftasks with precise accuracy while exhibit-ing virtually no degradation to the piezodevice, thus reducing long-term operat-ing costs within the system’s they reside.
Beginning in the late 1980s, piezo ele-ments made an entrance into moremainstream end products such as surgi-cal tools and ultrasonic cleaning for onevery good reason: Piezoelectric actua-tors are the fastest-responding position-ing element available with microsecond-time constants. Also, they can producemotions in sub-nanometer increments.The development of more economicallypriced piezo elements is the drivingforce behind the dramatic widening oftheir popularity with designers.
Equally dramatic is the recent emer-gence of equally price competitive highvoltage power amplifier ICs necessaryfor driving the elements.
Piezoelectric actuators require high-volt-age drivers delivering hundred of volts,peak-to-peak, and since a typical actua-
tor looks like virtually a pure capaci-tance to the driving amplifier, almost allthe power dissipation becomes the bur-den of the driving amplifier. Until now, ifa HV solution was found, then speedand quiescent current were issues. Slewrates of at least 300V/µs are a must toeven be considered in the running. Aquick look through the abundance ofhigh-voltage, high-speed, small-signaloperational amplifier ICs would disclosemany amplifiers with bandwidths in thehundreds of megahertz. However, if you
need to combine that speed with morethan 12V, as you do if you are planningto drive a high-speed piezoelectricdevice; your choices of suitable ampli-fiers shrink pretty fast.
Compounding this sourcing challengehas been the very limited number offabs with high voltage and high speedprocesses. Finding a power amplifiercapable of operation at 100+ volts, with an IC form factor and an IC price,has been tough. Hybrid amplifiers have
Figure 1. APEX ink jet schematic.
24 Power Systems Design Europe October 2005
been the most available solution, but at a price difficult to design in.
The availability of these highly soughtafter, but attractively priced, high per-formance power amplifier ICs is finallybecoming reality. Leading the develop-ment is Apex Microtechnology Corporationbased in Tucson, Arizona USA. Apexhas a long-standing reputation as aleader in designing very high voltagepower operational amplifiers, but asproduct design technology has dictated,their best offerings have been in hybridform factors. The Apex design engineer-ing team has bridged the IC technologygap by combining its own patented ICcircuitry with a fabrication partner willingto evolve the high voltage, high speedsilicon processes. As a result, the com-pany is now able to offer designers poweramplifier ICs that deliver the cost-effec-tive, high power performance they seek.
One very popular industrial applicationfor piezos is as an actuator providingprecision placement of droplets by indus-trial ink printers (see Figure 1). Theseare the printers found in date codingand lot coding processes for everythingfrom cereal boxes to pharmaceuticals.
In this type of application, designersseek to marry the rigorous voltagerequirements with better amplifier speed.This tandem performance means thevoltage can be applied quickly to thepiezo thus allowing the overall system to work faster. The derived benefit fromthis combination of speed and voltage iscritical to date coding operations. Theproduction line moves faster when theink jet printer does its job quickly. Thenew ICs in the Apex high voltage ampli-fier product offerings are the PA78,PA86 and PA69 (see Figure 2). These devices offer the sought-after
combination of high speed and highvoltage. This high speed trio providescustomers with various combinations ofhigh speed, high voltage, and as anextra bonus, very low standby current.Capable of achieving slew rates of up to350V/µs on supply voltages of 350V, thePA78 series bests its nearest competitorby more than 2X. The PA78 series alsodelivers up to 150mA of output currentwhile generating very little standby cur-rent – less than 1mA depending on per-formance requirements.
The intellectual property behind thePA78 series provides the secret to itssuccess. The IC’s design provides forextremely highslew rates in pulseapplications whilemaintaining verylow quiescent cur-rent of under 1mA.Slew rate perform-ance is independ-ent of supply cur-rent while exhibit-ing a functionalrelationship to volt-age amplitude.More simply stat-ed, as the inputsignal increases,so does slew rate.
Customers CanSimplify DesignChallenges withPA78 SeriesTarget applicationsfor the PA78, PA86and PA69 will uti-lize the devices’abilities to delivervoltage with speedto control precisemovement.
Customers designing piezo drive anddeflection circuits will be extremelypleased with the performance optionsthese ICs make possible. The ICs’unique input stage has the effect ofadding variables to the power responseand slew rate characteristics of theamplifier. This also translates to inputrelated effects on open loop gain and phase.
Figure 2. Apex high voltage amplifierproducts.
www.apexmicrotech.com
INDUSTRIAL ELECTRONICS
Table1. Key Specifications for the PA78 Series.
26 Power Systems Design Europe October 2005
Electronic ballasts have becomevery popular due to the advan-tages these devices offer to the
lighting industry. The MOSFET is one ofthe key components for electronic bal-last. Saving in energy, green houseeffect, government regulations and technological advances are some of thekey driving forces behind this market.Generating more light with less con-sumption of electric energy is veryimportant but at the same time theseballasts have to work in very harsh con-ditions such as ones with wide inputvoltage variations as well as varyingambient temperature. Due to the harsh-ness of these conditions, reliability isvery important. Fairchild has released anew 400V fast body diode MOSFETwhich makes the half- bridge topologyused for ballast applications very reli-able and cost effective.
Introduction Electronic ballasts have been avail-
able commercially since late eighties,but traditionally magnetic ballasts havebeen used for lighting. Magnetic ballastsare bulky and have several disadvan-tages and consume about 30% moreelectrical energy compared to electronicballast. Although it is true that electronicballasts cost more compared to magnet-ic ballast but the higher costs of elec-tronic ballasts are compensated hand-somely by reduced energy costs in the
long-term. Even with these advantagesit is very surprising that electronic bal-last sales have barely started to exceedmagnetic (copper-wound) ballasts,which are known to be physically bulki-er, heavier, and much less energy effi-cient. It is a well known fact that elec-tronic ballasts provide steady flicker-freelight and an instant start capability. Thesefeatures lead to stress-free workingenvironments for the eyes. Power-factorcorrection capability can also be addedwith some additional cost. Lighting fix-tures consume 10-12% of the total elec-trical power produced world wide.
There are different types of applica-tions such as Compact FluorescentLamps (CFLs), Cold Cathode FluorescentLamps (CCFLs), High-Intensity Lamps(HIDs) and Light Emitting Diodes (LEDs).However, two types of gaseous dis-charge lamps are available in the mar-ket today. One is the high pressure typeand other one is the low pressure type.The fluorescent lamp is a low pressuremercury vapor discharge lamp, and isthe more commonly used lamp.Theselamps are available in many sizes,shapes and power ratings. In case ofthe fluorescent lamp, the mercury vaporunder low pressure is sustained in theionized state by an external currentsource. This ionized mercury does notprovide light directly. The fluorescentlamp has phosphor coating which emits
light when bombarded by the ultravioletradiation from conducting gas.Combining all these applications togeth-er, the total market for electronic bal-lasts is estimated to be above one bil-lion units and is still rising at a slowpace. The input harmonics are con-trolled by either passive PFC or some-times active PFC. A boost switch (MOS-FET or some other power switch) isneeded for an active PFC. The secondstage for electronic ballast circuitry isgenerally a half-bridge topology. Recentimprovements in power semiconductorsand other components coupled with theincrease in energy cost and increasedconcerns about the environment aremaking these electronic ballasts verypopular. The efficiency of fluorescentlamps increases when operated at high-er frequency compared to 50/60 Hzpower line frequency. The electronicsballast when operated at high frequencyat about 20-50 KHz can increase thelamp efficiency by about 10%.
Half-Bridge InverterThe lamp current should be sinusoidal
in shape to minimize EMI. The sinewave current also maximizes the life ofthe lamp. High the ratio of peak currentto RMS current will reduce the life of thelamp cathodes. The DC componentapplied to the lamp should also be mini-mized to increase the life of cathode.Because of this a series-resonant based
Generating more light with less consumption of electric energy is very important but at the
same time these ballasts have to work in very harsh conditions such as ones with wide
input voltage variations as well as varying ambient temperature.
By Sampat Shekhawat; Fairchild Semiconductor
The device for ballast applications
INDUSTRIAL ELECTRONICS
voltage fed half-bridge inverter is one ofthe most popular topology to drive theCompact Fluorescent Lamp (CFL). Thecontroller used here is generally a highvoltage IC that drives both high side andlow side MOSFETs of the half bridge.The controller provides all of therequired functions to the voltage fedhalf-bridge inverter required for thelamp. These functions include preheat,ignition, burn state and protection etc.These controllers also provide low sideand high side gate driver. The controllerhas to be optimized for the electronicballast so that it occupies the minimumprinted circuit board area by reducingcomponent count and lowering powerdissipation as well as cost. The initialpreheating time and frequency can beadjusted depending on the type of lamp
used. The ballast has to work from lowline AC to high line AC input. Sometimesthese voltage excursions are more thanis allowed. Under these excursions, thevoltage fed half bridge inverter ballastcan make the lamp flicker if the rightMOSFET is not chosen.
Figure 1 shows the circuit diagram forthe typical electronic ballast. The lampand its series inductor L1 connectedacross A and B nodes act as a load tothe voltage fed half-bridge inverter. Thecapacitor C3 across the lamp electrodesand in series with L1 forms the resonantnetwork. The capacitors C4 and C5 arepart of the network for the controller cir-cuit. When Q2 is on these capacitorsare discharged.
During normal conditions whenevereither MOSFET is turned on, first itsbody diode conducts so the MOSFETturns on without switching loss as shownin Figure 2 (a) & (b). Figure 2(b) showsthat when Q1 is turned off its outputcapacitance is charged and at the sametime the output capacitance of Q2 is dis-charged because of the direction of loadcurrent under resonance, and Q1 turnsoff at ZVS. Once the output capacitanceof Q2 is discharged the current flowsthrough the body diode of Q2 and itsdrain to source voltage is clamped by itsown body diode forward voltage drop.When gate voltage is applied to Q2 asshown in Figure 2(b) and when the cur-rent changes direction, the MOSFETchannel starts to carry current in the for-ward direction, hence the MOSFET turn-on switching loss is negligible. When thecurrent changes direction the voltageacross the MOSFET is negligible com-pared to the DC bus voltage.
The starting frequency of the ballast is very high compared to the resonantfrequency or burn state frequency.However, at low line or even at high lineit may be in a hard switched modebefore reaching to burn in state or thiscircuit can misbehave due to dioderecovery problem since MOSFET bodydiode may try to recover under certainconditions before reaching a burn state.In this mode the diode recovers when its complimentary MOSFET is turned onand this current flows through Rshunt.The voltage across the Rshunt can
www.powersystemsdesign.com28 Power Systems Design Europe October 2005
www.fairchildsemi.com
influence the controller. The C4 and C5across Q2 also influence on this prob-lem. The diode recovery current as wellas the charging current for these capaci-tors passes through Rshunt when Q1 isturned on.
Sometimes when this current is veryhigh the controller can shut-off the bal-last thinking that there is a shoot throughacross the DC bus. The controller canalso misbehave under this condition andcan keep the lamp in an undesirableflickering mode. It was also found thatthis problem occurs only due to the lowside MOSFET diode recovery and thecharging of capacitors connected acrossthe lower switch. The body diodes of Q1and Q2 alone were not causing thisproblem. It was the combination ofMOSFET body diode recovery current
and the charging currentof the capacitors acrossthe power MOSFET Q2that was causing thisproblem.
To eliminate and con-firm this problem, aSchottky diode was con-nected in series with thedrain of Q2 (betweenthe drain of Q2 andnode-B of the inverter)and then a fast recoverystandard diode with lowQrr and Trr was con-nected across the seriescombination of the
MOSFET and the Schottky diode(across the source of Q2 and node-B ofthe inverter). This eliminated the prob-lem at both the low line as well as highline of AC input voltage.
Figure 4 shows that the diode recov-ery problem was gone and only a smallcurrent blip is there which is due to thecharging of capacitors connected acrossQ2. Because of the smaller current blip,the controller did not misbehave. Theballast works fine without entering intoflickering mode.
The body diode recovery characteris-tics of Fairchild MOSFET FQP6N40C,competitor-A and competitor-B weremeasured as shown in Figure 4. It wasdecided that the body diode was caus-ing this problem.
A fast body diode MOSFET for ballastapplications was designed. The MOSFETsQ1 and Q2 were replaced by Fairchild’sMOSFET FQP6N40CF. Some standardMOSFETs worked fine from nominal ACvoltage input to high line voltage, buthad problem at low line voltage.Competitor-A’s MOSFET worked finefrom low line to nominal line voltage, butit had problem at high line AC input volt-age. Competitor-B MOSFETs workedfine from low line to high line voltage buttheir breakdown voltages were lowercompared to other MOSFETs, and werenot reliable enough and had some fail-ures. However a MOSFET with fastbody diode eliminated these problemsand worked well at all input line voltageconditions and at the same time therewere no reliability problems. The peakcurrent through the current monitoringresistance, Rshunt, was reduced andthe on-off mode (flickering mode) of theballast was eliminated.
ConclusionThis article demonstrates the value of
using a fast body diode MOSFET for elec-tronic ballast applications. This fast bodydiode MOSFET eliminates the ballastflickering problem from low line AC inputvoltage to high line AC input voltagewithout forcing the controller to misbehave.
INDUSTRIAL ELECTRONICS INDUSTRIAL ELECTRONICS
Figure 1. Voltage-fed half-bridge inverter for electronic ballast.
Figure 2a. Normal operation of ballast. Figure 2b. Normal operation of ballast.
Figure 3. Body diode recovery of standard MOSFETs.
Figure-4a. Standard diode recovery waveform. Figure 4b. Different MOSFETs body diode reverse recovery@ 2A, di/dt=200mA/Sec and Vdd=200V.
29
30 Power Systems Design Europe October 2005
For new generation of lamps the ICoffers optimized functionality
The new generation of fluorescent lamps of the T4 and T5 type are optimized for high efficacy. In
order to achieve long lifetimes, they require a specific, more complex start-up procedure and an
intensive monitoring of the operating behaviour compared to the older lamp T8 and T12 types.
By Michael Herfurth, Infineon Technologies AG
Infineon Technologies has introduceda new controller ICB1FL01G to themarket, which controls electronic lamp
ballasts for fluorescent lamps. The con-trol concept offers a unique set of fea-tures and a comprehensive functionalityto operate single and multiple lamps at aminimum effort of external components(see Figure1). The new generation offluorescent lamps of the T4 and T5 typeare optimized for high efficacy. In orderto achieve long lifetimes, they require aspecific, more complex start-up proce-dure and an intensive monitoring of theoperating behaviour compared to theolder lamp T8 and T12 types. For thisnew generation of lamps the IC offersan optimized functionality.
The ballast controller ICB1FL01Gcontrols in a first functional block a
boost converter as an active harmonicfilter for the power factor correction. Asecond block of the IC controls a half-bridge inverter. The driver for the float-ing high-side MOSFET operates accord-ing to the level-shift method and makesuse of the new Coreless Transformertechnology. The inverter feeds the lampvia a resonant circuit.
Different operating modes such assoftstart, preheating ignition and runmode according to a fixed andadjustable timing sequence are con-trolled by the operating frequency of theinverter. The adjustment of the parame-ters determining time and frequency isdone solely by resistors, completelyavoiding any capacitors for this task.The device detects a lamp removal aswell as the dangerous rectifier effect at
the lamp’s end of life in configurations ofone, two and four lamps (see Figure 2).
Operating behaviour during start-upof the ballast
After switching on the mains thecapacitors C12 and C13 are charged viathe start-up resistors R11 and R12. Thecurrent consumption of the IC is typical-ly below 100µA until the supply voltagehas reached Vcc=10V. Above this levela current source of typically 20µA at theRES pin is activated to detect the exis-tence of the low-side filament. As longas the voltage level at the RES pin isbelow 1.6V the filament is assumed tobe undamaged.
Via the resistors R24 and R25 a cur-rent is fed to the high-side filament andvia the resistors R31, R32, R33 to theLVS1 pin. A filament is detected, if thecurrent is above 15µA. For multi-lampoperation a second detection pin LVS2is available, which can be deactivatedby a ground connection in the same wayas LVS1. In other words: if the existenceof the filaments is detected and the volt-age at the PFCVS pin has reached atleast 0.375V, which is interpreted asclosed regulation loop for the boost con-verter, the IC can activate its driver out-puts as soon as the supply voltage Vcchas exceeded the turn-on threshold of 14V.
Figure 1. Reference design of an electronic lamp ballast with ICB1FL01G.
INDUSTRIAL ELECTRONICS
32 Power Systems Design Europe October 2005
Inverter to feed the fluorescent lampThe inverter starts at a frequency of
120kHz. Within 10ms the frequency isreduced in 16 steps to the preheat fre-quency adjustable by the resistor R22.The duration of preheating can beselected between zero and 2,000ms bythe resistor R23. Subsequently the fre-quency is further reduced in 128 stepsand a time period of 40ms to the run fre-quency adjustable by the resistor R21(see Figure 3).
With the first pulse the low side MOS-FET Q3 of the half-bridge is turned on.Then the floating capacitor C14, whichsupplies the high-side control logic like abattery, is charged from capacitor C13via R30 and the diode D6. At the outputof the half-bridge inverter the capacitorC16 together with the diodes D7 and D8acts as a charge pump in order to supplythe IC via C13. In addition C16 is usedto limit the voltage slew rate and to pro-duce zero voltage switching conditions.
During operation C16 is rechargedwithout losses in the dead time periodsof MOSFET Q2 and Q3 by the inductivedriven current of the load circuit. So thesucceeding turn on of the MOSFET occursat zero voltage. At turn-off C16 limits thevoltage slew rate in such a way, that theMOSFET channel is already turned offbefore the Drain to Source voltage hasreached considerable levels. Thereforethe inverter creates negligible switchinglosses at normal operation.
The load circuit of the inverter con-sists of a series resonant circuit with theresonance inductor L2 and the reso-nance capacitor C20. The lamp is con-nected in parallel to the resonancecapacitor. For a voltage mode preheat-ing the resonance inductor L2 has twoadditional windings. Each of those wind-ings drives a current in the filament viathe band pass consisting of L21/C21and L22/C22. The band pass filterensures a current flowing through the fil-aments only during the preheat phase.
During the ignitionperiod a high voltageat the lamp and a largecurrent in the resonantcircuit is generateddue to the unloadedresonant circuit (seeFigure 4).
The current in theresonant circuit ismonitored by theresistors R24 andR25. A voltage higherthan 0.8V at pin LSCS
increases the operating fre-quency of the inverter by acouple of frequency steps.As a result of this measurethe ignition phase isenlarged from 40ms up to235ms with a lamp not will-ing to ignite, while the volt-age at the lamp keeps onthe level of the ignition volt-age with a certain ripple. Ifthe run frequency is notachieved within 235ms afterfinishing, the preheatingperiod the IC changes overinto the failure mode. Arestart is initiated either by
lamp removal or after a new cycle ofturn-off and turn-on of the mains voltage.
Preconverter for power factor correction
Simultaneously with the inverter theMOSFET Q1 of the PFC boost convert-er starts the operation. Such a boostconverter (L1, Q1, D5, C10) can trans-form the input voltage to any arbitraryhigher output voltage. Using a suitablecontrol method, this converter is used asan active harmonic filter and for the cor-rection of the power factor. The inputcurrent follows the same sinusoidalwave form as the AC mains supply volt-age. On the output of the PFC precon-verter a feedback controlled DC voltageis available at capacitor C10 for theapplication. The PFC stage is operatedwith a controlled turn-on time withoutinput voltage sense. A turn-on time setby the control unit is followed by a turn-off time which is determined by theduration until the current in the inductorand hence in the diode too has reachedthe level zero. This point of time isdetected by the voltage level at the zerocurrent detector winding on the inductorL1 and feed to the IC via the resistorR13 and the pin PFCZCD.
The result is a gapless triangularshaped current through inductor L1 (socalled critical conduction mode) which issustained for a turn-on time in the rangeof 23µs down to 2.3µs. A further reduc-tion of the energy flow reduces the turn-on time down to 0.4µs while at the sametime the turn-off time is extended caus-ing triangular shaped currents with gaps
Figure 2. Application circuit of an electronic lamp ballast with ICB1FL01G for a single fluorescent lamp.
Figure 3. Exemplary variation of frequency and lampvoltage during start-up procedure with different operating modes.
INDUSTRIAL ELECTRONICS
34 Power Systems Design Europe October 2005
(discontinuous conduction mode). Sucha control method allows a stable opera-tion of the boost converter over a largerange of the input voltage as well as ofthe output power.
The ICB1LB01 includes the erroramplifier with entire compensation buildup by a digital PI regulator and a digitalfilter to suppress the 100Hz ripple.
Protection featuresThe PFC section is provided with a
current limitation and a monitoring ofthe bus voltage in respect to overvolt-age, undervoltage and open controlloop. The inverter detects an overcur-rent, when the voltage at pin LSCSexceeds the threshold of 1.2V forlonger than 400ns. A single event is sufficient to change over into failure mode.
During run mode of the inverter adeviation from the typical zero voltageswitching is recognized as an operationwith capacitive load. In such an operat-ing condition peak currents occur dur-ing turn-on of the MOSFETs due to
switched charging of the charge pumpcapacitor C16. In a situation with partialrecharge of capacitor C16 the ICchanges over into the failure mode,when the situation happens for longerthan 500ms. In a second situation,capacitor C16 is completely rechargedby the MOSFETs switching. In such acritical operating condition with high
power dissipation the IC changes intofailure mode already after 605µs.
When the fluorescent lamp reachesthe end of lifetime the lamp voltage canbecome unsymmetrical or increase. Theresistors R31, R32, R33 measure thelamp voltage by evaluating the currentthrough these resistors at pin LVS1. Themaximum lamp voltage is detectedwhen the current through the resistorsR31, R32, R33 exceeds +/- 230µA. Therectifier effect with unsymmetrical lampvoltage is detected when the ratio ofmeasured positive and negative peakvalue at pin LVS is higher than 1.15 orlower than 0.85. The change into failuremode will be initiated when an end-of-life criteria happens for longer than500ms.
The integrated circuit ICB1FL01G hasa unique combination of features thatmake a design of high-quality lamp bal-lasts with a low number of external com-ponents possible.
Figure 4. Lamp voltage dependent onoperating frequency without load (redtrace) e.g. before ignition and with load(black trace) e.g. after ignition assum-ing a constant load resistor.
www.infineon.com/smartlighting
INDUSTRIAL ELECTRONICS
36 Power Systems Design Europe October 2005
Have power semiconductor packages in focus
The increased power density of the applications together with a general decrease in overall
physical size creates a difficult environment for the MOSFETs employed; they are
expected to handle more power.
By Chris Hill, Senior Applications; Philips Semiconductors
There is a general trend in today’sDC-DC converter market towardsproducts with smaller size and
greater power density. The power semi-conductors employed in those applica-tions are typically N-channel MOSFETs,which usually act as the high frequencyswitches within the converter circuits. In most cases, the MOSFETs havebecome a significant source of powerdissipation within such applications.However, the increased power densityof the applications together with a gen-eral decrease in overall physical sizecreates a difficult environment for theMOSFETs employed; they are expectedto handle more power, yet are placed inenvironments where cooling of theMOSFETs is increasingly more difficult.In all cases, it is essential that neitherthe MOSFET’s maximum operating tem-perature nor the maximum temperaturelimit of the PCB is exceeded.
Thermal resistancesIn all but the simplest cases, it is not
possible to manually calculate the tem-perature of MOSFET device(s) in a typi-cal application. The “traditional” meas-ures of thermal performance usuallyfound in device data sheets are the so-called “thermal resistances”. Thermalresistances are analogous to electrical
resistances and quantify the resistanceto the flow of heat energy along a pre-defined path. Thermal resistances aredefined in the following general manner;
Where;
Rth is the thermal resistancebetween two points
∆T is the temperature differencebetween the points
q is the heat flux flowing betweenthe points
The thermal resistance figures foundin MOSFET data sheets are Rth j-mb andRth j-a, and are applicable only undervery specific conditions – conditionswhich rarely, if ever, match those foundin a real application.
Rth j-mb is the thermal resistance fromjunction to mounting base, as shown inFigure 1.
Rth j-mb is relatively easy to measureand understand, however its usefulnessin a design situation is limited as it onlydescribes one small part of a thermalscenario comprised of many series andparallel paths.
Figure 1. Definition of Rth j-mb for an LFPAK MOSFET.
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38 Power Systems Design Europe October 2005
SummaryThe results of Table 1 show a good
correlation between measured and sim-ulated data – the simulated results arewithin ±6% of the measured results.Potential sources of error include thecalibration accuracy of thermocouplesand other test equipment and uncertain-ties as to precise thermal properties ofthe materials used in the simulation.
On the basis of these results, the useris able to have a high degree of confidenceboth in the PIP212-12M thermal modeland the thermal simulation software itself.
Detailed thermal models for a widerange of Philips MOSFETs are available
for download from http://www.smart-parts3d.com. The models cover manypopular package types including TO220,D-Pak, D2-Pak, LFPAK, SOT23 andTSOP6 and are provided free of charge.
Finally, Figure 4 demonstrates the useof the PIP212-12M thermal model in thesimulation of a “Point of Load” (PoL)DC-DC converter application. In thisexample, the PIP212-12M is mountedon a small rectangular PCB and fittedwith a heatsink on the topside of thedevice package in order to aid cooling.For clarity, the heatsink has been made“invisible” in this picture.
Literature/resources
Flothermhttp://www.flotherm.comJEDEChttp://www.jedec.orgSmartparts3dhttp://www.smartparts3d.com
www.semiconductors.philips.com/power
Table 1. The corresponding figures of Rth j-a.
Rth j-a is a measure of the total thermalresistance from the junction to ambientand takes account of all thermal path-ways, including those through the PCB.See Figure 2.
Whilst Rth j-a may appear to be a use-ful figure for the circuit designer to use,any given value of Rth j-a dependsheavily on test conditions, PCB con-struction, etc., and so probably will notbe appropriate in a designer’s specificapplication.
A full description of the test methodol-ogy for determining thermal resistancesmay be found in JEDEC specificationsJESD51-1 through JESD51-10. Itshould be noted that the Rth figuresdescribed in these documents werenever intended to be used in the designof real applications, despite widespreadattempts in the industry to do so.
In summary, therefore, it is not usuallypossible to manually calculate the tem-perature of MOSFET device(s) in a typi-cal application, and hence the circuitdesigner is often faced with the problemof needing to calculate device operatingtemperature, but having no practicalmeans of doing so. It is to meet thisneed that thermal simulation techniqueshave been applied to the field of elec-tronic circuit design.
What is thermal simulation software?The thermal simulation software
described in this article usesComputational Fluid Dynamics (CFD)techniques to analyse complex thermalscenarios involving coupled heat transferby conduction, convection and radiation.Although the principles of CFD are gen-erally applicable to many fields of engi-neering, Flomerics’ “Flotherm” package
is specifically targeted at users in the fieldof electronic and electrical engineering.
A particular strength of thermal simu-lation software is that it enables design-ers to eliminate unusable configurationsfrom their designs at a very early stagein the design process. Hence a finished,working solution may be arrived at in amuch shorter time compared to a situa-tion where thermal simulation softwareis not used, and actual prototype con-struction may be unnecessary untilmuch later in the design process.
Thermal modeling of the PhilipsPIP212-12M Integrated Solution.
The “Wire Frame” view of the PIP212-12M thermal model is shown in Figure 3.
This is an example of a “detailed”model where internal components suchas the silicon and leadframe have beenincluded. The PIP212-12M IntegratedSolution is a good example of a thermal-ly complex device. The PIP212-12M ishoused in a 56-pin Quad Flat Packpackage and comprises three internalheat sources (two MOSFET die plus adriver chip) together with various con-ductive leadframe and wire-bond com-ponents. Heat energy is free to flow notonly from the sources to ambient butalso between the sources via the otherinternal conductive components.
Verification of the PIP212-12M ther-mal model.
A sample of the PIP212-12M wasmounted on an aluminum test PCBmeasuring 35mm x 30mm x 1mm. The junction temperatures of the twoMOSFETs were measured separatelyfor known values of junction dissipation(PD) using the “body diode thermome-try” method - see JEDEC specificationJESD51-1 for a full description of the test method. Using the methoddescribed in JESD51-1 we are able todetermine the junction temperatures ofthe PIP212-12M for a correspondingrange of values of PD and hence thecorresponding figures of Rth j-a. Theresults are shown in the table 1.
Figure 2. The numerous thermal pathways from junction to ambient for anLFPAK MOSFET.
Figure 3. Wire Frame view of the PIP212-12M detailed model.
Figure 4. PIP212-12M detailedmodel after simulation, showingtemperature plot.
INDUSTRIAL ELECTRONICS INDUSTRIAL ELECTRONICS
40 Power Systems Design Europe October 2005
The IPM eliminates around 20 discrete components
The IRMCK203, implements all control algorithms in dedicated hardware logic, enabling very high
bandwidth closed loop control. In practice, the device is faster than traditional motor control DSPs,
and can perform a complete Field Orientation Control (FOC) loop in 6µs.
By Naresh Shetty, International Rectifier
Permanent magnet (PM) ACmotors generally deliver morepower and torque for their size
than induction motors, and thereforeenable numerous enhancements to awide variety of industrial, scientific andmedical (ISM) equipment. But develop-ers must be able to configure suitablevariable speed drives quickly, if they areto make the most of these inherentadvantages. Bringing up a custom solu-tion is lengthy and requires expensivedesign and integration skills. A well-con-ceived motor control design platformoffers the opportunity to enhance per-formance while at the same time reduc-ing time to market, design effort, anddesign risk.
PM AC motor designsThe favourable power and torque
characteristics of PM motors, especiallythe higher torque at low shaft speedscompared to conventional inductionmotors, allows designers to design-outexpensive gearboxes in favour of directdrive controls. The PM motor also doesnot display slip, which leads to improveddynamic control by eliminating the needfor slip compensation.
Hence PM motors will allow ISMequipment such as CNC machine tools,aerospace controls, robotic equipmentand light industrial machinery, and semi-conductor processing equipment suchas wafer handlers to become smaller,lighter, more efficient, and more cost-effective. Also, industrial appliancessuch as air conditioning units and com-mercial refrigerators can benefit fromthe same acoustic noise and efficiencyadvantages that PM motors bring todomestic appliance markets. Here, theability to operate at the optimal speedfor any given set of conditions and userdemands, rather than running continu-ously at full speed, can dramaticallyreduce overall electricity consumptionleading to significant savings in opera-tional costs for commercial enterprises.
In many ISM applications, rangingfrom machine-shop automation to small,precision instruments such as dentaldrills, traditional software-based meth-ods of motor control simply do not reactquickly enough to suit modern require-ments. In addition, equipment develop-ers need a much more highly integrated– and easy to configure - solution to PM
motor control, which will allow them tofocus on additional value-added fea-tures while at the same time reducingtime to market and leveraging the inher-ent PM motor performance benefits.
Solutions for rapid developmentA suitable rapid development solution
for PM motor control will comprise a dig-ital control block – preferably a single IC- with register-customisable controlalgorithms already implemented in hard-ware. But this alone is not enough tosignificantly reduce the design and inte-gration effort for state of the art motordrives. Developers also need compati-ble, plug and play components includingdriver stages, IGBTs from low to highcurrent ratings, and functional blocks to perform analogue duties such asmotor protection.
International Rectifier has created adigital control IC for sensor-less high-speed permanent magnet motors. The IC supports operation over a widespeed range, and is ideal for sinusoidalcurrent control. This device, theIRMCK203, implements all control algorithms in dedicated hardware logic,
INDUSTRIAL ELECTRONICS
www.powersystemsdesign.com42 Power Systems Design Europe October 2005
This floating capability allows differen-tial-mode signal processing on top of a600V or 1200V common-mode voltage.Integrated HVIC gate drivers such asInternational Rectifier’s IR2214 andIR22141, which combine as a high-sideand low-side pair, save considerabledesign complexity, effort and risk. Forexample, the technology now allowsdesigners to create a single-chip solu-tion to the challenge of driving a MOS-FET or IGBT in the high side position ofa half-bridge topology or 3-phase invert-er leg, where the gate voltage is refer-enced to the source rather than to ground.
With HVIC, implementing full protec-tion - including ground fault protection –is now viable for a wide range of appli-cations. In the past, this has only beenfeasible in high-end systems. TheIR2214 and IR22141 gate driversinclude parameter matching, such aspropagation delay for high- and low-sidechannels as well as deadtime insertion.Low quiescent current on the high-sideenables economical and space-savingbootstrap supply topology. There is alsofault feedback on IGBT de-saturation,which automatically shuts down theIGBT when used in multi-phase configu-rations. The IR2214 includes desatura-tion detection for both sides as well asan internal biasing resistor, while theIR2241 includes an active de-saturationdiode bias. The IR2214 and IR22141can be connected together via a dedi-cated pin to protect the drive systemfrom phase-to-phase short circuits.Finally, separate power and signalground pins, enable emitter shunt con-figurations to simplify low-side IGBTcurrent sensing.
Figure 2 shows how the IRMCK203and IR22141 and IR22141 may be com-bined to create a 380/460V AC sensor-less permanent magnet motor controlsystem for use in a professional industri-al application such as a high-speedspindle or pump.
One Step FurtherAn Integrated Power Module (IPM)
enables even higher integration forlower voltage industrial drives, such asthose in the range 85V-253V and 750-
1200W. The IPM eliminates around20 discrete components by combin-ing HVIC gate drivers and sensing with a three-phase inverter powerstage built using IR’s non-punch-through (NPT) short-circuit-ratedIGBT technology.
One example, internationalRectifier’s 20A, 600VIRAMY20UP60B has an internalshunt resistor as well as a built-intemperature monitor, and enablesover-current and over-temperatureprotection as well as under-voltagelockout: all in a compact SIP3 pack-age featuring internal heat spread-ers for the power die. A similardevice, the IRAMX20UP60A doesnot include the shunt resistor but ispackaged in a more compact SIP2outline. An open emitter configura-tion of the low-side IGBT switchesoffers easy current feedback andover-current monitoring for high precision and reliable control.Similar IPMs, rated to 16A, are also available.
Together with a few external com-ponents and a controller, the IPMenables a complete motor drivesystem. This greatly accelerates thedesign path compared to a multi-discrete solution. Other integratedfeatures such as the bootstrapdiodes for the high-side drive func-tion and the single polarity powersupply, simplify the system design while reducing overall cost anddelivering the wider benefits of high-er integration, including boardspace savings, enhanced reliabilityand easier inventory management.
www.irf.com
enabling very high bandwidth closedloop control. In practice, the device isfaster than traditional motor controlDSPs, and can perform a completeField Orientation Control (FOC) loop in6µs. By comparison, a high performancemotor control DSP typically requires 15-20ms. Where a practical implementationmay call for a torque control bandwidthof 4kHz, which implies a maximum com-putation update period of 25ms, theDSP has little headroom to implementother functions. These may includepower management, start-up retry,phase loss detection, low loss and low
EMI space vector PWM, and variousdrive protections. A single DSP or MCUusing a real-time multi-tasking operatingsystem will struggle to perform thesediverse tasks in a timely manner, but theIRMCK203 performs all of these on-chipin addition to executing the FOC algorithm.
To configure a controller using theIRMCK203, the developer writes appli-cation-specific parameters into on-chipregisters during system configuration,via a PC-based development environ-ment. The actual inverter hardware canalso be designed within this environment,
which enables the added advantage ofperforming “hardware in the loop” sys-tem evaluation with a real, industrialquality drive, to by-pass time-consumingiterative bread-boarding of hardwareand software. Hence this approachdelivers a complete motor control systemdevelopment platform that allows a smallteam to manage the complete designprocess while meeting the increasingdemand for higher performance.
No programming effort is required tofinalise complex PM motor control algo-rithms for execution in the IRMCK203.Combined with optimal IGBTs and highvoltage gate drivers and current sensingfabricated using International Rectifier’sHigh Voltage Integrated Circuit (HVIC)technology, the user can implement acomplete AC servo and sensorless con-trol with minimum component count anddesign effort.
Integrated Protection and SensingIGBT gate drive, protection and sens-
ing functions can all now be integratedonto a single monolithic chip using HVICtechnology as shown in Figure 1. HVICessentially enables low voltage CMOScircuits to be referenced to a high-volt-age floating supply level for high-sidegate-drive and signal-processing circuits.
Figure 1. Implementing 380/460V sensorless PM motor system.
Figure 2 Common circuit blocks of HVIC.
INDUSTRIAL ELECTRONICS
44 Power Systems Design Europe October 2005
Decades of transformer design experienceare built into the tool
PI Transformer Designer is the first tool that automatically creates complete transformer
designs with detailed specifications. Considering the ever-shrinking design windows that
today’s marketplace demands, this tool will be indispensable to those who design low-cost,
low-EMI power supplies.
By Peter Vaughan, Power Integrations
IntroductionPower supply ICs that include a MOS-
FET integrated with a controller on thesame piece of silicon have been com-mercially available for about a decadenow. Some of these ICs also have themost commonly used support functions,such as over-temperature shutdown,under- and over-voltage protection, andcycle-by-cycle current limiting integratedonto the chip. The reduction in compo-nent count, circuit complexity, size, costand design cycle time that results fromdesigning power supplies around theseICs has made them very popular withpower supply design engineers.
The integration of support functionsonto these ICs has also greatly simpli-fied the process of designing safe,robust, energy-efficient power supplies.This has enabled engineers who are notexpert power supply designers to pro-duce solid designs quickly and easily.With the deadlines for complying withthe newest energy-efficiency standardsclose at hand, many applications needto have compliant solutions quickly
designed to replace line-frequency, lin-ear-regulated power supplies, which willnot be able to comply.
Tools, tools and more toolsAlthough these ICs have helped to
greatly simplify switched-mode supplies,most models still require a custom high-frequency power transformer. With somany variables involved in the design ofpower magnetics, designing optimizedtransformers can be challenging, evenfor experienced magnetics engineers.Good transformer design is all the moreimportant since high light-load efficiency,low no-load consumption and low EMIare all impacted by the performance ofthe transformer.
Most IC manufacturers provide appli-cation notes and software aids to sup-port their devices, but these tend tofocus mainly on the electrical circuitdesign. At best, some of these aids willproduce a list of electrical transformerparameters, and at worst, many providelittle more than a few rules of thumb forexperienced transformer designers.
With the burden of designing commer-cial magnetics increasingly falling uponengineers who have little knowledge ofthe art, Power Integrations recognizedthe need for a solution more compre-hensive than a list of electro-magneticdesign parameters. With this in mind,the latest version of the company’seasy-to-use PI Expert Suite design soft-ware contains a utility that provides acomplete transformer specification.
Introducing PI Transformer DesignerPI Transformer Designer is the first
tool of its type that automatically pro-duces full specification, step-by-steptransformer winding instructions anddetailed winding diagrams. Decades oftransformer design experience are builtinto the tool, which allows even a noviceto create a design that can be wound ina lab, or sent out to a magnetics vendorwith assurance that the samples built to the winding instructions will workproperly the first time.
INDUSTRIAL ELECTRONICS
46 Power Systems Design Europe October 2005
Simple to Use Yet ComprehensiveTo use PI Transformer Designer, the
engineer simply opens a design that hasbeen produced using PI Expert. In thedefault mode, everything is calculatedautomatically, and a finished transformerspec is produced without any user inter-action. In the fully manual mode, theuser makes all of the design decisions.This flexibility allows the tool to be use-ful to engineers of all experience levels.
PI Transformer Designer providessupport for designs that use tape mar-gins and those that use triple-insulatedwire to meet electrical isolation require-ments. Wire gauges and filar count (the number of parallel strands woundtogether) are calculated based on manyvariables including input and output cur-rent limits, usable winding window area,etc. The tool also specifies foil windingswhen it makes the most sense to usethem. The number of layers a particularwinding occupies in the bobbin isdynamically calculated based on thespecific wire / filar combinations or the
foil sizes selected. Where necessary,split primary construction is used toreduce leakage inductance and improveefficiency. If directed to do so, the toolalso specifies layers of tape betweenthe primary winding layers in order toimprove light-load efficiency and reduceno-load power consumption.
To aid the designer in selecting a suit-able transformer bobbin, the minimumnumber of pins required on the bobbin is shown, taking into account the maxi-mum number of individual strands ofwire that can be terminated onto a sin-gle pin. This helps the user to select asuitable bobbin, and helps to ensurethat the finished transformer can be successfully produced in high volumes.Once a bobbin has been selected andthe number of actual primary and sec-ondary pins has been chosen, the soft-ware automatically updates all of the pinreferences in the electrical diagram andthe winding instructions, reducing thechance of errors.
Shield Windings Defend Against EMIEMI is always a challenge in power
supply design. Engineers often have toresort to expensive EMI filter compo-nents to make a power supply meet EMIstandards. However with the click of amouse, the user can incorporate PowerIntegrations’ patented E-Shield windingtechniques into a transformer design.The software automatically selects themost appropriate shielding scheme and optimizes it for the specific design.These winding techniques reduce thegeneration of EMI currents, the need forfilter components, and the time and effortit takes to make a supply meet its EMIrequirements, which shortens the timeto market for the end product. To illus-trate this, figure 2 compares the con-ducted EMI measurements (EN55022 Blimits) of the same power supply using atransformer that was built without the E-Shield techniques (plot “a”) versus onebuilt with E-Shields enabled (plot “b”).
Figure 1. PI Transformer Designer Provides Detailed a Transformer Specification Automatically.
INDUSTRIAL ELECTRONICS
www.powersystemsdesign.com 4948 Power Systems Design Europe October 2005
The difference can be dramatic, with typically 15-20 dBmV of noise levelreduction occurring, especially in simple,low-power designs with limited input fil-tering. For designs where very low leak-age currents (<10 mA) are specified,
such as chargers for metal-encased cell phones, this reduction in EMI canallow the Y-class capacitor normallyused to bridge the isolation barrier to be significantly reduced in value orremoved completely.
Optimizing the shielding of a transformerto reach an acceptable EMI solution cantake weeks of work, and require thewinding of 10, 20 or even 50 trans-former samples, each with subtle varia-tions of shielding schemes, winding
Figure 2. Enabling Shields Has a Dramatic Effect on Conducted EMI.
INDUSTRIAL ELECTRONICS
www.powersystemsdesign.com 51
NEW PRODUCTS
STMicroelectronics has introduced areference design platform for the emerg-ing market for electronic power meters.Electronic energy meters are replacingtraditional electromechanical meters inmany residential, commercial and indus-trial applications because the versatilityand low-cost afforded by electronic meterdesigns allows meter manufacturers toimplement many features that were impra-ctical with the older mechanical designs.
By drawing on its port-folio of dedicated andstandard products andworking closely withindustry leaders in thepower-metering field. Thereference platform pro-vides a modular solutionthat can be adapted bysoftware to meet the utili-ty company’s particularneeds. It comprises twoprinted circuit boards,one dedicated to the
mains power measurement functionsand one implementing sophisticatedcomputational and supervisory func-tions. The measurement board supportsall current measurement technologies,from the most accurate Rogowski coilsto inexpensive shunt resistors. It canmonitor both Live and Neutral currentfor tamper detection and complies withall international standards such as IEC-
62052-11 and IEC-62053-2x for meter-ing equipment (AC).
The STPM01 can be used as a stand-alone device in 1-phase kWh meters oras a peripheral in microprocessor-based 1-phase or 3-phase energymeters, in which case active (base andwide), reactive and apparent energy,VRMS, IRMS, instantaneous voltage andcurrent, and line frequency readings areavailable through the SPI bus.
The Control Board is based on anST7 microcontroller and is supplied witha library of C-code software, with manyadditional software routines availablefree of charge from the ST website. The reference design also includes theM41ST87 real-time clock chip, a 256-kbit serial SPI bus EEPROM and a dedi-cated 32-character alphanumeric LCDwith on-glass driver.
www.st.com/metering
Simplifying ‘Smart’ Electric Power Metering
www.power-one.com
Power-One has expanded its BLP55Series by adding the BLP55-3000 andthe BLP55-3300 triple-output ac-dcpower supplies. These products areideal for 1U "pizza-box" applications asthey are very cost effective and can pro-vide enhanced flexibility in the physicallayout and power distribution architec-
ture of the host system. Host-system physical-
layout flexibility isenhanced by reducedairflow requirements(eliminating the need tobe directly adjacent to acooling fan) and a low1.25" height that reducesairflow shadowing toimprove cooling of down-stream devices. Power-distribution architectureflexibility is enhanced bythe availability of 3.3 and5V outputs, suitable for
any desired combination of bus voltageand/or direct-power usage.
Both models accept a wide-range 85to 264VAC input, and only need 10 LFMof cooling to provide full-rated power.The BLP55-3000 delivers +5V @ 5A,+12V @ 2.5A, and -12V @ 0.7A. The
BLP55-3300 provides +3.3V @ 5A, +5V@ 2.5A, and +12V @ 0.7A. Additionalfeatures include a compact 3.00 x 5.00x 1.25 inch (76.2 x 127.0 x 31.8 mm)package that is compatible with indus-try-standard footprints and connectors,remote sense, and output overvoltageprotection.
Regulatory agency approvals includeUL recognition to UL60950-1/CSA 22.2No. 60950-1 and TUV approval toEN60950-1. Onboard EMI filtering pro-vides Class B compliance to FCC CFRTitle 47, Part 15, Sub-Part B -Conducted; and EN55022/CISPR 22Conducted Class B.
Multi-Output Power Supplies
arrangements, wire type, and numbersof turns. The process becomes evenmore laborious if taking EMI measure-ments means trips back and forth to alocal test facility. Thus, this one featureof the software alone can save thedesign engineer weeks of work.
Speeding PrototypesOnce the transformer design is com-
plete, the results can be used to make aprototype in-house, or sent to a vendorto have samples made. The detailedinstructions and diagrams reduce thechance of construction errors. Manymagnetics vendors prefer that samplesbe specified in this way because it elimi-nates several cycles from the samplingprocess. The design results can beexported in a variety of formats for docu-mentation purposes. Finally, clicking theTransformer Vendor List button on thetool bar will open a web page that listsvendors who regularly work with PItransformer specifications.
SummaryPI Transformer Designer is the first
tool that automatically creates completetransformer designs with detailed speci-fications. Considering the ever-shrinkingdesign windows that today’s marketplacedemands, this tool will be indispensableto those who design low-cost, low-EMIpower supplies for tomorrow’s applica-tions. Finally, can such a valuable toolbe affordable?
Since PI Expert Suite 6.0 can beordered or downloaded for free from thePower Integrations web site, (www.pow-erint.com/designsoftware) who canafford to pass it by?
www.powerint.com
INDUSTRIAL ELECTRONICS
www.powersystemsdesign.com5352 Power Systems Design Europe October 2005
Advanced Power Technology Europeannounced a new product line of FieldStop, Trench Gate IGBT standard powermodules. These new products broadenour offering of 600V products in the SP3and SP6-P, and introduce a completenew line of 600V, 1200V and 1700Vdevices in SP4 and SP6 packages.
All these products offer minimum
VCE(sat) saturation voltage (typically1.5V for 600V, 1.7V for 1200V and 2Vfor 1700V). They are dedicated to lowfrequency operation where overall sys-tem efficiency is a concern. The idealswitching frequency is 20 kHz for 600V products, 10 kHz to 20 kHz for1200V products and up to 10 kHz for1700V products.
These modules are offered in buck,boost, dual buck, dual boost, dual common source, phase leg, full bridge,asymmetrical bridge, triple phase leg and triple dual common source configurations.
Current rating range from 20A to 600Afor 600V devices, 50A to 400A for1200V devices and from 50A to 300A @for 1700V devices, all rated withTc=80°C.
Key Features are: Very Low Profile –Same as Industry Package SOT-227Height for SP3 and SP6-P; Space andCost Savings - Small Footprint;
Solderable Terminals - Easy PCBMounting for SP3, SP4 and SP6-PPackages; M5 Screw Terminals for SP6;Wide Range of Voltage and CurrentRatings; Very Low Inductance; HighEfficiency - Low VCE(sat) SaturationVoltage; Very Short Tail Current;Isolated Package - Easy Mounting toHeat Sink and Easy to Parallel - PositiveTemperature Coefficient.
Main applications for this extendedfamily are motor drives, UninterruptiblePower Supplies, welders, plasma cutters,solar inverters, inductive heating, solidstate relays for three phase mains andother applications where low conductionis of primary concern. The very low pro-file offering low parasitics inductancesmakes this product range a componentof choice when space, electrical per-formance, weight and cost are a concern.
Field Stop, Trench Gate IGBT Power Modules
www.advancedpower.com
NEW PRODUCTS
Littelfuse has introduced its Lead-freeand RoHS compliant SL0902 series asa new addition to its Greentub family ofproprietary gas plasma arresters (GasDischarge Tube or GDT).
Designed for use in broadband andhigh-speed telecommunications the
SL0902 series, is a miniature gas plas-ma arrester (GDTs) designed to be aviable alternative to silicon surge protec-tors when high bandwidth and lowcapacitance are required. The SL0902is Littelfuse’s smallest “BroadbandOptimized” gas plasma arrester. Forovervoltage components such as theSL0902, “broadband optimized” meansthat the product enables performanceenhancement through a combination oflow insertion loss, no capacitance varia-tion with voltage and temperature, andexcellent voltage clamping — all ofwhich are requirements for broadbandequipment in order to prevent surge
damage while maintaining data integrity.The SL0902 meets these requirementswithin a very small footprint.
The SL0902 series is designed towork in conjunction with the LittelfuseTeleLink surface mount fuse in applica-tions where both fusing and surge pro-tection are necessary. The small foot-print SL0902 series can be accommo-dated on D0-214AA solder pads, provid-ing that a D0-214AA is present on theboard allowing for replacement of ahigher capacitance silicon device withthe ultra low capacitance SL0902 series.
www.littelfuse.com
Gas Plasma Arresters
www.irf.com
International Rectifier has launchedthe R6 line of high-reliability (HiRel)100V, 150V, 200V and 250V radiation-hardened (RAD-Hard) MOSFETs forpower management circuits.
The R6 devices are designed for DC-DC converters, motor controls and solid-state switching circuits with input volt-ages of 24V to 48V in launch vehicles,satellites and other demanding applica-tions enabling them to be made morecompact, reliable and efficient.
For example, the IRHNJ67130, with
0.042Ohms device on-resistance reducespower dissipation in power supply appli-cations. Its low total gate charge of 35nCfurther reduces power consumption.
The new R6 MOSFETs have SEE rat-ings to LET of 90MeV and improvedprompt dose response and SEE absorp-tion versus other equivalent devices. Inaddition, the new devices are optimizedfor use in Hybrid - MIL-PRF-38534“Class K” modules for satellite applica-tions, including low Earth orbit (LEO),middle earth orbit (MEO), geostationary
earth orbit (GEO) and deep space mis-sions. Devices are available in surface-mount as well as new low-ohmic TO-254and TO-257 packages. Tab-less TO-254and TO-257 packages are also available.
Radiation reports are available on theHiRel Radiation Reports page:www.irf.com/product-info/hi-rel/radrpt.html
The new R6 mid-voltage RAD-HardMOSFETs are available immediatelyand are subject to U.S. export controllaws and regulations.
RAD-hard MOSFETs deliver 40% better on-resistance
ABB is producing the first VoltageDetector VD1500, adapted completelyto meet the major specifications of thetraction market. The new ABB VoltageDetector VD1500 has been designedincorporating a new ABB innovation, a100% electronic solution. This safetyproduct will be used in applications suchas on-board railway equipment (main
converters, auxiliary converters) and inpower electronics systems (batterychargers, choppers, sub-stations, etc.).It allows the maintenance operator toverify the presence of a dangerous volt-age (AC or DC) up to 1500V on anyequipment. Dangerous voltage indica-tion is provided via 2 independent LEDsthat flash when the voltage detected ishigher than a specified limit (maximum50V according to standards such asCF60-100). The mechanical and elec-tronic concept ensures an excellent reli-ability of the product through two inde-pendent electronic boards (redundancyof the same function in only one prod-uct). The Voltage Detector (VD) oper-ates from –40°C up to +70°C. The VDrange has been designed to comply with traction standards: EN50155 for
high-tech electronic design and tests,EN50124-1 for electrical insulation andEN50163 for voltage. The VD range hasalso been designed in compliance withsafety standard EN50129 for communi-cation, signalling and processing systems.
The ABB Voltage Detector provides acost-effective solution that is easy toinstall and use.
ABB has been concerned for long withthe protection of the environment andhas been ISO 14001 certified in 1998.This environmental approach is particu-larly noticeable in the production of the VD range with the reduction of thenumber of components, use of a low-energy manufacturing procedure andrecyclable packing.
www.abb.com/lowvoltage
ABB Voltage Detector
NEW PRODUCTS
54 Power Systems Design Europe October 2005
LEM has introduced two new mem-bers of its IT family of current transduc-ers to address high-current applications.The IT 400-S and the IT 700-S arespecified respectively for 400 and 700ARMS nominal. As with other membersof the family, they offer very high accu-racy, based on resolution better than
0.05 ppm, linearity better than 3 ppmand an initial offset between 30 and 50ppm. Thermal offset drift is extremelylow, at only 0.5 ppm/K.
Featuring galvanic isolation, the IT400-S and IT 700-S can be used for current measurement of any kind ofwaveforms (including DC, AC, mixedand complex). They have been designedto operate from a bipolar +/-15 V DCpower supply and will accommodateround primary conductors of 26 and 30mm diameter respectively.
In addition to their normal current output, the transducers offer an addi-tional output indicating the transducer
state (opened or closed contacts), and an external LED showing the normal operation.
With an operating temperature rangeof +10 to +50°C, the transducers willfind applications in high-precision powersupplies and high-performance gradientamplifiers for MRI (Magnetic ResonanceImaging), as well as medical equipmentsuch as medical X-Ray imaging, butalso calibration test benches in labora-tories and test departments. They canalso be used as interfaces for poweranalysers when high accuracy is required.
www.lem.com
High Accuracy Current Transducers
NEW PRODUCTS
Continuing to provide power supplymanufacturers with innovative ways toreduce power consumption, ONSemiconductor (NASDAQ: ONNN)today introduced the NCP1603 – a comboPFC/PWM controller with integrated stand-by and high voltage startup capabilities.
The NCP1603 combines a power fac-tor correction (PFC) controller chip anda pulse width modulation (PWM) controlchip in a single, 16-pin SOIC package.This combination simplifies the task ofdesigning an offline, ac-dc power supplythat simultaneously meets governmentalrequirements for power factor correctionand low standby power consumption.Target applications for this device includeproducts such as notebook and LCDadapters, and other consumer electronics.
In these applications, PFC is typicallyrequired when a power supply is operat-ing under normal load conditions.However, in light-load and no-load con-ditions, a PFC is not required and gen-erates losses that make it almost
impossible to meet the limits on standbypower consumption established by theCalifornia Energy Commission, EnergyStar, and other organizations.
Under light load conditions, theNCP1603 PWM controller disables thePFC function, saving in the range of 200milliwatts (mW) of power. Currently, themost aggressive standards limit standbypower consumption to 500 mW withplans to lower this limit to 300 mW in thefuture. Given those goals, the powersaved by turning off the PFC is signifi-cant. Moreover, disabling the PFCensures that the controller can meeteven the 300 mW limit for standby power.
www.onsemi.com
Efficient PFC/PWM Controller
IXYS announces the release of a newfamily of 100V to 600V Standard andHiPerFET Power MOSFETs based onIXYS New Technology Platforms, PolarHTand PolarHV incorporating a proprietarycell-design that reduces on-resistanceby 30%, enabling improved efficiency.
IXYS’ proven HiPerFET process yieldsPower MOSFETs with a fast intrinsicbody diode for low Qrr and enhanceddV/dt ruggedness. IXYS’ HiPerFETs aretargeted at hard switching inverter andpower supply applications. These prod-ucts are currently finding significant use
in demanding IT and telecom switch-mode power supplies that require effi-cient switching and energy conversion intight enclosures, as well as applicationswhere high reliability is critical.
The PolarHT line is available to sup-port applications requiring voltage rat-ings from 100V to 300V, ranging acrossa broad spectrum of consumer, industri-al and automotive markets. Examplesinclude telecomm switch mode powersupplies and motor drives for the indus-trial market, plasma display and audioamplifiers for consumer applications and
ignition systems and electric vehicles forthe automotive market. These devicesbridge the gap between high voltagetechnology and low voltage TrenchMOSFETs.
PolarHV starts at 500V and 600V, withextension to higher voltages planned.IXYS offers one of the broadest rangesof current ratings, with product extend-ing from 1A to 80A and above. Productswill be offered in various standard pack-ages, including the full spectrum of sur-face mount and discrete packages.
www.ixys.com
Fast and Rugged Power MOSFET Technology
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3 Power Systems Design Europe October 2005
NEW PRODUCTS
Companies in this issue
Company Page Company Page Company Page
ABB Switzerland . . . . . . . . . . . . . . . . .1,53Advanced Analogic Technology . . . . . . .56Advanced Power Technology . . . . . . .24Advanced Power Technology . . . . . . . .29Anagenesis . . . . . . . . . . . . . . . . . . . . . . .1Analog Devices . . . . . . . . . . . . . . . . . . . .4Ansoft . . . . . . . . . . . . . . . . . . . . . . . . . .11Ansoft . . . . . . . . . . . . . . . . . . . . . . . . . . .1APEC . . . . . . . . . . . . . . . . . . . . . . . . . . .47Apex Microtechnology . . . . . . . . . . . . . .22Artesyn Technologies . . . . . . . . . . . . . .1,4Bergquist . . . . . . . . . . . . . . . . . . . . . . . .9C&D Technologies . . . . . . . . . . . . . . . . . .4CT-Concept technology . . . . . . . . . . .27Curamik . . . . . . . . . . . . . . . . . . . . . . . . .1Danfoss . . . . . . . . . . . . . . . . . . . . . . . .34EPCOS . . . . . . . . . . . . . . . . . . . . . . . . .43Ericsson . . . . . . . . . . . . . . . . . . . . . . . . . .6Fairchild Semiconductor . . . . . . . . . .C2Fairchild Semiconductor . . . . . . . . . . .1,26Ferraz Shawmut . . . . . . . . . . . . . . . . . .52Fisher Elektronik . . . . . . . . . . . . . . . . .48
Fuji Electric . . . . . . . . . . . . . . . . . . . . .31Hitachi . . . . . . . . . . . . . . . . . . . . . . . . . .13Infineon Technologies . . . . . . . . . .1,10,30International Rectifier . . . . . . . . . . . . .C4International Rectifier . . . . . . . . . . .1,40,53iSuppli . . . . . . . . . . . . . . . . . . . . . . . . . .12IXYS . . . . . . . . . . . . . . . . . . . . . . . . . . .16IXYS . . . . . . . . . . . . . . . . . . . . . . . . . . .54LEM Components . . . . . . . . . . . . . . . . .3LEM Components . . . . . . . . . . . . . . . .1,54Linear Technology . . . . . . . . . . . . . . . . .5Linear Technology . . . . . . . . . . . . . . . .1,8Littelfuse . . . . . . . . . . . . . . . . . . . . . . . .53Magnetics . . . . . . . . . . . . . . . . . . . . . . .50Micrel . . . . . . . . . . . . . . . . . . . . . . . . . .25Micrel . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Mitsubishi Electric . . . . . . . . . . . . . . . .20National Semiconductor . . . . . . . .18,19National Semiconductor . . . . . . . . . . . . .1Ohmite . . . . . . . . . . . . . . . . . . . . . . . . .33Ohmite . . . . . . . . . . . . . . . . . . . . . . . . . . .1On Semi - EBV Elektronik . . . . . . . . . .37
On Semiconductor . . . . . . . . . . . . . . .1,54Philips Semiconductors . . . . . . . . . . . . .36Power Integrations . . . . . . . . . . . . . . . .7Power Integrations . . . . . . . . . . . . . . .1,44Power One . . . . . . . . . . . . . . . . . . . . . . .51Power System Design China . . . . . . .49Power System Design Europe . . . . . .55Productronica . . . . . . . . . . . . . . . . . . .41Rutronik . . . . . . . . . . . . . . . . . . . . . . . . . .6Semikron . . . . . . . . . . . . . . . . . . . . . . .23Semikron . . . . . . . . . . . . . . . . . . . . . .1,14SPS/IPC Drives . . . . . . . . . . . . . . . . . .45ST Microelectronics . . . . . . . . . . . . . . . .51SynQor . . . . . . . . . . . . . . . . . . . . . . . . . .1Texas Instruments . . . . . . . . . . . . . . . .15Texas Instruments . . . . . . . . . . . . . . . . . .1Tyco Electronics . . . . . . . . . . . . . . . . .39Tyco Electronics . . . . . . . . . . . . . . . . . . .1Vishay . . . . . . . . . . . . . . . . . . . . . . . . . .35Wurth . . . . . . . . . . . . . . . . . . . . . . . . . .48
Please note: Bold—companies advertising in this issue
Advanced Analogic Technologies(AnalogicTech) has introduced theAAT2803, a multi-function, high efficien-
cy, dual charge pump that supports bothwhite LED backlight and camera flashapplications for portable systems that
run on lithium-ion/polymer batteries. The device offers independent control of three separate LED banks (two forbacklight and one for camera flash) andfeatures seven channels total (six forbacklight and one for camera flash). The AAT2803 delivers major power andspace savings for handsets featuringtwo displays, and adds a light loadmode to minimize power consumptionwhen the handset display is active instandby mode.
Most of today’s handsets feature twodisplays, either in a clamshell designwith a main display on the inside and asecondary display on the outside or in abar design with a main display and akeypad backlight by combining inde-pendent control of two separate banksof backlight LEDs with flash capabilityand a light load mode in a single device,the AAT2803 charge pump helpsdesigners minimize power consumptionwhile reducing component count andpackage size.
www.analogictech.com
Six-Channel Backlight Charge Pump from AnalogicTech
