Systems Design Motion and Conversion April 2007

ZKZ 64717

04-07ISSN: 1863-5598

Bodo s Power SystemsBodo s Power Systems

IGBT Modules

Power Management

Magnetic Materials

Communication Power

MAKING MODERN LIVING POSSIBLE

The big E – family

Danfoss Silicon Power GmbH • Heinrich-Hertz-Straße 2 • D-24837 Schleswig, Germany • Tel.: +49 4621 9512-0 • Fax: +49 4621 9512-10E-mail: dsp-sales@danfoss.com • http://siliconpower.danfoss.com

• Widest range of E-type modules• Standard or individual housings• Flexible pin-out• Custom or standard circuits• Silicon from world class suppliers• IGBTs and MOSFETs• Low and high voltage• For industry, electric vehicles,

renewable energy and medical

To meet your exact requirements 3099

C O N T E N T S

1www.bodospower.com Bodo´s Power Systems - April 2007

Viewpoint

Oscar, Hollywood meet Goofy, Anaheim . . . . . . . . . . . . . . . . . . . .2

Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7

Product of the Month

ORing-FET Controllers Reduce Power Loss . . . . . . . . . . . . . . . .8

Guest Editorial

Power Electronics Engineers Needed

By Claus Petersen, Danfoss Silicon Power . . . . . . . . . . . . . . . .10

Market

The Lennox Report; By Robert Lennox . . . . . . . . . . . . . . . . . . .12

Market

Low-Power Wireless to Push DC-DC

Converter & Regulator ICs; By Linnea Brush,

Senior Research Analyst, Darnell Group . . . . . . . . . . . . . . . .14-16

VIP Interview

Interview on Power Management Technology

with Donald E. Paulus, Vice President and General Manager,

Power Products, Linear Technology . . . . . . . . . . . . . . . . . . .18-19

Cover Story

Smart Pumping: Motion-Control Advancements Aid

Intelligent-Pumping Applications

By Aengus Murray, International Rectifier . . . . . . . . . . . . . . .20-22

IGBT Modules

Improving the Thermal Cycling Capability

of Cu Baseplate Modules; By K. Guth and Th. Schütze;

Infineon Technologies AG, Germany . . . . . . . . . . . . . . . . . . .24-25

Opto

Simple Technique for LED Driver Applications

By Ajmal Godil, Intersil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26-27

Magnetic Materials

New Ferrite Material Improves Split-Core Current

Transformers for Power Measurement; By Pierre Turpin,

Energy & Automation Project Manager, LEM . . . . . . . . . . . .28-29

Product of the Quarter

Heavy - Duty Ultracapacitor Module; By Maxwell . . . . . . . . . . . .30

Power Management

Overcoming Challenges in Design

By Robert Bell, Applications Engineer

National Semiconductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32-25

Snap Shots of Product Innovation at APEC . . . . . . . . . . .36-41

Communication Power

Single Port PoE Controller Simplifies PSE Design

By Alison Smith, Product Marketing Manager, Mixed Signal

Products,Linear Technology Corporation . . . . . . . . . . . . . . . .44-45

New Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46-48

Bodo´s Power SystemsBodo´s Power Systems

Bodo´s Power Systems - April 2007

Going to California in winter is always nice.

Having a few days of summer weather and

seeing friend’s in El Segundo is a great start

for the season of conferences and exhibi-

tions.

Browsing in Hollywood the weekend before

APEC provided glamorous pictures from the

entertainment world - and their main event,

the Oscar Awards ceremony. APEC is a

similar event for power electronics – but

instead of getting Oscars, everyday we had

Goofy around. I have chosen a few of what I

believe could be Oscars for Power

Electronics and have listed them as “Snap

Shots of Product Innovation” at APEC. The

experts meet at APEC - Hollywood should

consider them for Oscar awards - it is their

basic work that keeps all the fancy elements

going to create today’s movies.

Power electronics provides the heartbeat of

communications and entertainment, but we

need efficient conversion technologies to

keep up with all the toys we are collecting. I

learned from an Article published by the

IEEE Computer Society that 15% of the USA

electrical consumption is used for comput-

ing-related power usage. This area has

potential to further reduce waste and

increase efficiency. Computing usage

increases inevitably, and the services related

to computer-supported entertainment have

become a fast growing market. To keep up,

we need to improve efficiency in power con-

version.

Back home in our neighbourhood in Europe,

the exhibitions and conference season also

has begun. The race to the summer holiday

started with the EMC conference in Stuttgart.

Stuttgart clearly showed that EMC is based

on good design. Testing only provides confir-

mation of meeting directives. Design is the

essential level, as testing does not accom-

plish good performance.

Moving ahead - the upcoming SMT show in

Nuremberg has a strong tie to efficiency in

power electronics. Optimised modules and

hybrids, together with the right semiconduc-

tors, are in pursuit of the remaining percent-

ages in efficiency. Void free soldering tech-

nology is one step to homogeneous thermal

conditions and a platform for optimised ther-

mal management. So the SMT show is an

avenue to more efficient module solutions.

These range from IGBT-modules to DCDC

power supplies.

The next big event is PCIM Europe, in

Nuremberg in May. My special focus there

will be the Green Power subject. Mark your

calendar for the podium discussion “Green

Power - The Challenge of Smarter Design”

on Wednesday, 23rd of May 2007, 12:05-

12:50, Hall 12 Booth 357.

Stop by at Bodo’s Power Systems booth and

a chance to win a young engineers educa-

tion kit: a Märklin starter set. Electric Trains

have given a lot of influence to my career

and should be a good start for young kids

today. Just drop off your business card at

our booth, Hall 12 Booth 457 and mark your

children‘s name and age on it. The drawing

will take place on Wednesday, 23rd of May

2007, 14:00. The winner has to be present

at the booth to take away the prize, not the

children – just yourself !

Looking forward to see you and chat in

Nuremberg.

Best Regards

Oscar, Hollywood - meets

– Goofy, Anaheim

Bodo´s Power SystemsBodo´s Power Systems

A Media

Katzbek 17a

D-24235 Laboe, Germany

Phone: +49 4343 42 17 90

Fax: +49 4343 42 17 89

editor@bodospower.com

www.bodospower.com

Publishing Editor

Bodo Arlt, Dipl.-Ing.editor@bodospower.com

Creative Direction & Production

Repro Studio Peschke

Repro.Peschke@t-online.de

Free Subscription to qualified readers

Bodo´s Power Systems magazine

is available for the following

subscription charges:

Annual charge (12 issues) is 150 €

world wide

Single issue is 18 €

subscription@bodospower.com

Printing by:

Central-Druck Trost GmbH & Co

Heusenstamm, Germany

A Media and Bodos Power magazine

assume and hereby disclaim any

liability to any person for any loss or

damage by errors or omissions in the

material contained herein regardless of

whether such errors result from

negligence accident or any other cause

whatsoever.

Events

TI Power Supply Seminars Q2,

http://www.ti.com/europe/power07-b

Hannover Fair, April 16-20, Hannover,

http://www.hannovermesse.de

National Power

Management Design Seminars,

April 25 – May 16

http://www.national.com/euseminars

Fairchild Power Seminars

www.fairchildsemi.com/powerseminar07

SMT, Hybrid, April 24-26, Nuremberg,

http://www.mesago.de

PCIM Europe, May 22-24, Nuremberg,

http://www.pcim.de

Sensor+Test 2007, May 22-24, Nuremberg,

http://www.sensor-test.de

euroLED2007, June 5-7, Birmingham UK,

http://wwweuroled.org

EPE, September 2-5, Aalborg DK,

http://www.epe2007.com

Husum Wind, September 18-22, Husum D,

http://www.husumwind.com

Electrical Power Quality and Utilisation,

Oct. 9-11, Barcelona.

http://www.epqu2007.com

V I E W P O I N T

2 www.bodospower.com

To help your innovationwe make ourselves small.

Minisens is taking miniaturization to the next level as it is a fully fledged current

transducer for isolated current measurement including magnetic concentrators

in an IC SO8 size. This allows you to include all the functionalities you are look-

ing for into the space that you have available.

• Non-contact current measurement

with no insertion loss

• Isolation provider

• Attractive price

• Flexible design allows a wide

range of current measurement

from 2-70 ARMS

• +5V power supply

• Access to voltage reference

• Ratiometric or fixed gain and offset

• Standby mode pin

• Dedicated additional fast output for

short circuit detection

• High performance gain and offset

thermal drifts

www.lem.com At the heart of power electronics.

Minisens, FHS Current transducer

Maxwell Technologies, Inc. announced that

Professor Burkhard Goeschel, who retired in

November 2006 as a member of the six-per-

son Management Board of BMW Group, with

overall responsibility for research, develop-

ment and purchasing, has been appointed to

Maxwell’s board of directors.

Dr. Richard Balanson, Maxwell’s president

and chief executive officer, said that

Goeschel’s extensive experience and con-

tacts in the automotive industry will make

him a valuable strategic resource to man-

agement as the company accelerates devel-

opment and delivery of ultracapacitor-based

energy storage and power delivery solutions

for transportation applications.

“Professor Goeschel understands ultra-

capacitor technology and how it can be

applied to optimize energy storage solu-

tions for hybrid and electric drive trains

and to better satisfy the growing electri-

cal system needs of all vehicles,”

Balanson said. “He has indicated that he

intends to take an active role as a

sounding board for our technical staff, as

well as tapping his extensive worldwide

network of transportation industry con-

tacts to assist in Maxwell’s business

development efforts.”

Goeschel, 61, joined BMW in 1978, and

advanced through a series of technical

and management positions in the com-

pany’s automotive and motorcycle

groups before being appointed to its

Management Board in 2000. Earlier, he

spent two years as a Group Leader for

engine product development with

Daimler Benz.

He holds a PhD

degree in engi-

neering from

Stuttgart

University and

bachelors and

masters degrees

in mechanical

engineering from

the Technical

University of

Munich. He is an honorary professor of the

Technical University in Graz, Austria, holds

an honorary doctorate from the Technical

University of Munich and is a member of the

university’s management board

and a trustee of its Institute for Advanced

Studies. He is a member of the Council for

Technical Sciences of the Union of German

Academies of Sciences and Humanities,

serves on the Research Commission and

the Scientific and

Ethical Advisory Board for state of Bavaria,

and was general chairman of the Society of

Automotive Engineers

(SAE) 2006 World Congress.

www.maxwell.com

Maxwell’s New Member on the Board of Directors

N E W S

4 www.bodospower.comBodo´s Power Systems - April 2007

Ansoft Corporation executives Dr. Zoltan

Cendes, founder and CTO, and Nicholas

Csendes, CEO, received the Emerald Asset

Management E-3 award for entrepreneurial

excellence in the Science and Technology

Company Executive category at the 14th

annual Emerald Groundhog Day Investment

Forum in Philadelphia.

“We’re honored that Emerald has given us

this prestigious award,” said Csendes. “Our

solid business model and entrepreneurial

spirit have served us well since our found-

ing, and we will continue to

provide our customers with innovative high-

performance electronic design software

while nurturing a productive work environ-

ment and generating even more value for

our shareholders.”

Emerald’s team of research analysts and

portfolio managers award corporate leaders

who have demonstrated a creative approach

to corporate achievement; an entrepreneurial

approach that maximizes

human initiative; a corporate culture that pro-

motes excellence; an established record of

creating jobs, stimulating growth and

enhancing share-

holder value; and

an ability to effec-

tively identify and

adapt

cutting-edge tech-

nologies and

processes.

www.ansoft.com

www.teamemerald.com

Ansoft Executives Receive Emerald E-3 Award

Power manage-

ment with a dif-

ference present-

ed by Alex Lidow

CEO

International

Rectifier at PCIM

2007 on

Tuesday the

22nd of May at

13:00 on the

Forum Hall 12 Booth 347.

The more efficiently we use our energy, the

better we live because the cost of energy

saved goes back directly into our standard of

living once the cost required to effect the

energy savings is subtracted.

Almost one third of the world’s global con-

sumption of all forms of energy can be

saved as a result of improved power man-

agement. This paper will discuss how adopt-

ing electronic power management technolo-

gies that deliver energy-savings at cost pari-

ty when compared to traditional electro-

mechanical solutions will significantly grow

our global standard of living while minimizing

the impact on our environment.

www.irf.com

Delivering Global Energy Savings

PowerManagement

DesignSeminars

Meeting Power Design Challenges

Europe’s leading event on the topic of

System Integration in Micro Electronics takes

place in Nuremberg, with

SMT/HYBRID/PACKAGING 2007. From

design and development, PCB production,

components, construction and placement

technologies right through to test equipment,

the complete spectrum will be presented in a

comprehensive and compact way.

The combination of exhibition and applica-

tion oriented conference provides all atten-

dees with an ideal overall platform, offering

interesting synergy effects. Suppliers, scien-

tists and experts from all over the world will

display and explain how today´s burning

issues of production in the highly minia-

turised electronics world may be solved in

an economic approach.

Highlights of SMT/HYBRID/PACKAGING

2007:

The production line in Hall 7, presented joint-

ly by “VDI/VDE Innovation + Technik GmbH”

and partners from industry and research,

promises to be a real hit. A live production is

demonstrated under the motto:

“Multifunctional Packaging - an Innovative

Trend in Electronic Module Manufacturing”.

In addition the presentations are supported

by numerous demonstration islands.

Feature Area: The Bob Willis Process

Advice & Defect Clinic

Each day of the exhibition visitors will be

able to visit the “Process Advice & Defect

Clinic” with questions, process issues or

defects for examination and discussion. This

is an ideal opportunity to gain practical inde-

pendent advice on the most common causes

of production problems and field failure.

Optic meets Electronic - Photonic System

Integration at SMT

The advent of optical technologies is another

important topic in electronics. The trend-set-

ting advantage of optical joining techniques

in essential areas is a decisive aspect here.

Under the conceptual auspices of the

“Fraunhofer IZM”, companies show their

know-how on the key topics: electro-optical

packages, modules and assemblies, optical

interfaces and materials, production tech-

nologies and plant for among others, optical

and automotive communication, optical sen-

sor technology and systems, integrated illu-

mination systems, illumination and many

more.

Exhibition Forums

The SMT/HYBRID/PACKAGING 2007

Exhibition Forums will offer a 3-day compre-

hensive programme. Numerous companies

will present their products, solutions and

services, and sector experts will discuss,

amongst others, the following topics:

10 Months RoHS: First Experiences; users

give an account of success and problems,

25 April 2007, 14.00-15.00, led by: Hilmar

Beine, Hüthig Verlag

Practical Lead-Free Rework & Reliability

Issues, 25 April 2007, 15.00-16.00, Bob

Willis

Conference and Tutorials

The SMT/HYBRID/PACKAGING conference

with tutorials, taking place concurrently with

the exhibition, is the most important applica-

tion-oriented meeting point of the micro elec-

tronics industry, providing insight into and

the opportunity to discuss the latest research

results, solutions and user experience.

The conference day on April 25, 2007 (held

in German) will deal with “Architecture and

Technologies for High Current Circuit Boards

and Thermal Management”, an imperative

topic to deal with, given the increasing com-

plexity and integration density, both horizon-

tally and vertically, on and in the circuit

board, the approach of electronics into high

temperature functional groups and increas-

ingly intensive utilisation of the circuit board

for assemblies of power electronics

After an introductory presentation by the

company DaimlerChrysler, 13 renowned

speakers from industry and development will

pay closer attention to the topic. The focal

point will be on implementation examples

with different concepts of thermal transfer,

the architecture of high current circuit boards

and relevant aspects of electro migration

through to high temperature soldering mate-

rials. It is the aim of this conference day to

provide insight into resolution methods of

thermal management for ever more sensitive

electronics and improved and novel strate-

gies in assembling high current circuit

boards. Contributions on the topics electro

migration, soldering materials and soldering

will conclude the topic. Prof. Dr. Wolfgang

Scheel, Fraunhofer Institute for Reliability

and Microintegration, and Annemarie Biener,

Fuba Printed Circuits GmbH, will be chairing

the sessions.

In addition 27 half-day tutorials are on the

program on April 24 and 26, 2007, of which

9 will be presented in English. The variety of

topics spans across the entire value adding

chain of electronic assembly production,

from design through process technology to

quality assurance. Leading experts of the

sector will report in three-hourly sessions

about their concrete experiences and will

demonstrate their solutions. Developers,

manufacturers, suppliers and users will find

answers to their day-to-day questions.

www.smt-exhibition.com

N E W S

5www.bodospower.com Bodo´s Power Systems - April 2007

SMT/HYBRID/

PACKAGING 2007

System Integration in Micro Electronics International Exhibition & Conference

24 - 26 April 2007, Exhibition Center Nuremberg

N E W S

6 www.bodospower.comBodo´s Power Systems - April 2007

Within the

scope of

expanding and

complement-

ing its technol-

ogy and prod-

uct portfolio,

Epcos has

acquired Aktiv

Sensor GmbH.

This medium-

sized electron-

ics company (headquarters: Stahnsdorf/

Berlin/ Germany, sales in 2006: over EUR 5

million, approx. 60 employees) specializes in

the market for pressure sensors and sys-

tems. Aktiv Sensor possesses comprehen-

sive competence in development, production

and applications. By contrast, Epcos is one

of the world’s leading manufacturers of sen-

sors and sensor systems for temperature

measurement. With the acquisition of Aktiv

Sensor Epcos now becomes an electronic

components manufacturer able to offer tem-

perature and pressure sensors from a single

source.

“Aktiv Sensor’s technology and product

range fit very well with our existing portfolio,”

says Dr. Werner Faber, Member of the

Management Board and Chief Technology

Officer of EPCOS. “This acquisition opens

up new business opportunities to us in the

future-oriented sensor market, strengthens

our technology competence and thus

improves our market position and competi-

tiveness in this growth market.”

The combination of temperature and pres-

sure sensors creates a comprehensive syn-

ergy potential for EPCOS. On the one hand,

both product groups are frequently used in

the same applications – especially in auto-

motive and industrial technology – and are

consequently in demand by the same cus-

tomer group. On the other, the market is not

only demanding discrete components, but

increasingly combined sensors that can

measure both pressure and temperature.

www.epcos.com

Epcos buys Aktiv Sensor

Nextreme Thermal Solutions, a manu-

facturer of advanced thin film thermo-

electric components designed and pro-

duced to address the thermal manage-

ment needs of the electronics, photonics,

bio-tech and defense/aerospace indus-

tries, has recently appointed Dr. Seri Lee

as Chief Technology Officer.

Prior to joining Nextreme, Dr. Lee served

as Senior Thermal Scientist for the

Silicon and Platform Solutions Group at

Intel Corporation, where he was respon-

sible for executing corporate thermal

directions for consumer products and

technology development requirements.

As an active member of the ASME Heat

Transfer Division K-16 Committee on

Heat Transfer in Electronic Equipment

and the IEEE/SemiTherm Executive

Committee, Dr. Lee brings a wide range

of thermal management experience to

Nextreme.

“I am excited to welcome Dr. Lee to

Nextreme, as his experience is a part of our

plan to build a world-class technology team

focusing on electronic and opto-electronic

packaging and thermal management,” said

Jesko von Windheim, CEO at Nextreme. “I

believe that Dr. Lee’s addition positions the

company to address many of the most

demanding issues in thermal management

for advanced technology products; in addi-

tion, Dr. Lee will bring a new focus to the

company’s efforts in the area of thermoelec-

tric power generation.”

Dr. Lee has also previously held positions at

Amkor Technology as Manager of Thermal

Characterization, Aavid Thermal

Technologies as Director of Advanced

Thermal Engineering and at the University of

Waterloo in Ontario as Assistant Professor of

Mechanical Engineering.

http://nextremethermal.com

New CTO at Nextreme Thermal Solutions

... in Paris, Prague,Darmstadt, Hanover,Madrid, Rome, Zurich,Stockholm and Coventryfrom April 25 – May 16.

Dates, agenda and registration under:

www.national.com/euseminars

Parker Hannifin Corporation, parent compa-

ny of Chomerics Europe, has announced the

acquisition of the Tecknit Division of

Technical Wire Products, LLC and its affili-

ates, a global provider of electromagnetic

interference (EMI) shielding products.

Revenues of the acquired business totaled

approximately $18.3 million in 2005.

Earnings are expected to be accretive to

Parker in the first full year. Terms of the deal

were not disclosed.

Commencing operations in 1958, the Tecknit

business is headquartered in Cranford, New

Jersey, employs approximately 250 people,

and occupies over 90,000 square feet of

manufacturing and office space in the U.S.,

UK, Mexico and China. Its manufacturing

facilities are ISO 9001:2000 certified.

Steven Ferrie, CEO of Technical Wire

Products, LLC stated, “The acquisition of the

Tecknit division by Parker provides Tecknit’s

customers, employees, and many valued

business partners the opportunity to work

with a world class company that is commit-

ted to providing innovative EMI Shielding

Material solutions to the many markets that

Tecknit serves.”

Tecknit will be integrated into Parker’s

Chomerics division, a unit of Parker’s global

Seal Group. Heinz Droxner, President of

Parker’s Seal Group, commented that

“Tecknit’s facilities in strategic locations in

Europe, North America and Asia enable us

to more effectively integrate manufacturing,

sales, service and logistics to serve our

global customers in an increasingly competi-

tive environment.

www.parker.com

www.chomerics.com

Parker’s acquisition of Tecknit

N E W S

7www.bodospower.com Bodo´s Power Systems - April 2007

Fairchild Semiconductor will hold its annual

Power Seminars at locations worldwide start-

ing April, 2007. Fairchild is The Power

Franchise and its power experts will provide

the latest in design techniques for optimizing

system power with analog, discrete, and

optoelectronic solutions at these one day

events.

The 2007 Power Seminar technical sessions

include:

• Low Cost, Isolated Current Source for

LED Strings.

• Design Considerations of LLC Resonant

Converter.

• Application Review and Comparative

Evaluation of Low-Side MOSFET Drivers.

• Understanding Diode Reverse Recovery

and its Effect on Switching Losses.

• Tips and Tricks to Get More Out of Your

SPICE Simulations.

• Design Review: Power Stage Design for a

200W Off-Line Power Supply.

The Power Seminars will be held in Europe,

North America, Asia, Korea, and Central and

South America. For a complete listing,

including abstracts of the sessions, a

detailed schedule, and to register for a semi-

nar please go to Fairchild’s website at

http://www.fairchildsemi.com/powersemi-

nar07

www.fairchildsemi.com

Worldwide Technical Seminars

This year’s EMV Exhibition & Workshops

closed its doors in Stuttgart and 134

Exhibitors attracted 2572 Visitors. Stuttgart is

imbedded in the heart of an economy region,

which is marked

by mechanical engineering and automotive

industry like no-where else. Once again

EMV was the international meeting place of

the EMC industry for users and experts from

all areas of the electrical and electronic

industry. The exhibition even exceeded the

exhibitors´ expectations.

The positive atmosphere during the three

days in Stuttgart proved EMV 2007 to be the

exhibition and conference highlight for the

EMC-World. Based on the high quality of the

attendance, the exhibitors anticipate good

follow-up business after the fair.

EMV 2007 Stuttgart stands out for its the-

matically broad spread and above all practi-

cal workshop programs. Fourty one half-day

workshops in German and English tackled

the full spectrum of electromagnetic compati-

bility. 1291 guest had signed up for a work-

shop.

Once again, the number of workshop book-

ings showed how much the programs fitted

the industry’s need. Looking forward to 2008

in Düsseldorf.

www.mesago.de

Successful EMC Conference

Thomas

Winkler (38),

since the

beginning of

2007 is

Executive Vice

President of

Mesago

Messe

Frankfurt

GmbH and its

subsidiaries

Mesago Messemanagement GmbH and

Mesago PCIM GmbH. Together with

President Chairman Joseph Rath, Thomas

Winkler promotes the success of the special

interest exhibitions, congresses and semi-

nars of Mesago and is particularly committed

to the establishment and expansion of new

activities. Before joining Mesago Messe

Frankfurt GmbH, Thomas Winkler was for

six years General Manager of Enea

Embedded Technology GmbH, Munich,

responsible for the central European region.

His particular focus was Sales. Thomas

Winkler gained international experience par-

ticularly through setting up a sales organisa-

tion for Enea Embedded Technology in India.

Thomas Winkler is a qualified engineer in

Electrotechnology. He completed his studies

at the University of Rostock. At the Open

University Business School he completed a

Master of Business Administration (MBA)

programme by correspondence study.

www.mesago.de

Executive Vice President of Mesago

Microsemi announced the addition of a new

single-port gigabit power over Ethernet

(PoE) midspan to its PowerDsine(tm) prod-

uct portfolio.

Designated the 3001G, this newest member

of the PowerDsine 3000 midspan family

eliminates the need for external power sup-

plies at remotely deployed Wireless LAN

access points and other low-density net-

works having 10/100/1000 Base-T Ethernet-

connected devices. It is fully compliant with

the IEEE 802.3af PoE standard and can pro-

vide remote power to either 802.3af-compli-

ant or pre-standard devices.

The 3001G midspan offers a proprietary

interlocking feature that allows users to scale

WLAN deployments by linking together multi-

ple one-port midspans as new devices are

added to the network. With the interlocking

feature, users no longer have to deal with

conventional single-port power injector solu-

tions that do not interlock and often cause

troublesome entanglement of wires as new

devices are added.

Combined with a centralized UPS power

supply, the 3001G midspan provides a cost-

effective way to distribute back-up power to

every WLAN access point in the network,

increasing service reliability by ensuring con-

tinued operation in the event of power fail-

ures.

Complete product information is available at

http://www.powerdsine.com

www.microsemi.com.

Powering Remote Wireless LAN Access Points

Texas Instruments introduced a family of ORing power controllers

with advanced features and high performance that improves power

distribution in 12-V blade servers, N+1 telecom systems and redun-

dant low-voltage processor power supplies. The integrated circuits

provide a high-efficiency replacement for ORing diodes, and offer

intelligent monitoring and control of power supplies to prevent bus

transient events from causing board-damaging faults or voltage

spikes during operation. TI demonstratet the new controllers at the

Applied Power Electronics Conference (APEC), February 26 - March

1, 2007, in Anaheim, Calif. See: www.ti.com/sc07025.

TI’s new TPS241x family of ORing controllers support input voltages

of 3 V to 18 V, and can control power supply voltages down to 0.8 V.

When used with a low Rdson N-channel MOSFET, the controllers

significantly increase system efficiency and reduce power dissipation

compared to today’s standard ORing diode solutions. The TPS241x

devices seamlessly manage power distribution to multiple supplies,

while protecting the system from potentially dangerous reverse-cur-

rent or transient events by providing an extremely fast turn-off

response of 130 nanoseconds. In addition, the controllers feature a

programmable turn-off threshold and an input filtering function to pro-

tect the power supply’s integrity, especially when the system must

adjust to various bus characteristics caused by extreme and heavy-

use operating conditions.

The TPS2410 and TPS2412 con-

trollers incorporate linear gate

control, giving power system

designers greater flexibility to

implement ORing in high-power

applications. The TPS2411 and

TPS2413 controllers utilize

ON/OFF gate control to support

low-power buses that may experience large transient steps.

The TPS241x devices seamlessly manage power distribution from

multiple supplies, while protecting the system from service interrup-

tions or damage due to shorted power sources. Bus integrity is pro-

tected by providing an extremely fast turn-off response of 130

nanoseconds. The controllers feature a programmable turn-off

threshold, and programmable input filtering on the TPS2410 and

TPS2411, to provide flexible tailoring to various bus characteristics

caused by extreme and heavy-use operating conditions.

The TPS2410 and TPS2412 controllers incorporate linear gate con-

trol, giving power system designers the ability to eliminate continuous

reverse current into a lower-voltage input which can be very large in

high-power applications with low-Rdson MOSFETs. The TPS2411

and TPS2413 controllers utilize forward voltage ON with reverse volt-

age OFF gate control which is especially useful in systems that expe-

rience large transient steps from light load.

Key Specifications of the TPS2410:

• Controls external FET for N+1 and Oring

• Wide supply voltage range of 3 V to 18 V

• Controls buses from 0.8 V to 18 V

• Linear or on/off control method

• Accurate and adjustable threshold permits

precise control of turn-off

• Control mechanisms permit device operation to be tailored to the

application

• Soft turn-on feature reduces bus transients

• Internal charge pump for N-channel MOSFET

• Industrial temperature range of -40o to +85oC

Available Now

The TPS241x family of power controllers is available now in volume

production from TI and its authorized distributors. The devices come

in a 14-pin, plastic, thin small-outline package. Suggested resale

pricing for the TPS2410 and TPS2411 is $1.70 each in quantities of

1,000 units. The low-cost TPS2412 and TPS2413 versions, which

come in an 8-pin, thin small-outline package, are $1.20 each in quan-

tities of 1,000. Evaluation modules for the TPS2410 and other TI hot

swap controllers and power management application notes and

design tools are available through power.ti.com.

About Texas Instruments:

Texas Instruments Incorporated provides innovative DSP and analog

technologies to meet our customers’ real world signal processing

requirements. In addition to Semiconductor, the company includes

the Education Technology business. TI is headquartered in Dallas,

Texas, and has manufacturing, design or sales operations in more

than 25 countries.

www.ti.com

P R O D U C T O F T H E M O N T H

8 www.bodospower.comBodo´s Power Systems - April 2007

ORing-FET Controllers

Reduce Power Loss

Protect N+1 and Redundant Power Supply Systems

CO2 emission has recently moved up on the

international political agenda and most likely

will be the object of numerous near term leg-

islation. While writing this editorial, the EU

heads of state are negotiating maximum

CO2 emission targets and targets for the

binding rates of renewable energy to be

achieved by each country. From the per-

spective of a Power Electronics manufactur-

er this is good news. Power Electronics play

a significant role in a large number of CO2

emission reducing activities.

Renewable energy generation technologies

such as wind turbines, photovoltaic and

wave power all involve use of Power

Electronics, as do many energy consumption

technologies all the way from home appli-

ances to industrial automation. These seg-

ments from which Power Electronics has

been enjoying good growth in the past will

certainly contribute with higher growth rates

in the future.

In the decade ahead, however, the automo-

tive OEM market will emerge as a fast grow-

ing segment for Power Electronics. Fuel

saving Power Electronics applications such

as Electric Steering, Battery Management,

Electric Water pumps, Turbochargers and

Air-conditioning Compressors will contribute

with immediate growth. The Hybrid Car will

be an especially significant contributor and

will probably make the automotive industry,

by far, the single largest market segment for

Power Electronics.

Being a 2nd Tier automotive supplier with all

the know-how and intellectual property it

takes to succeed in the automotive Power

Electronics sector, this is just what you like

to hear, unless, of course, stumble blocks

are piling up ahead.

Significant challenges lie ahead. There will

be new component and system level tech-

nologies to develop and investments in new

manufacturing facilities, etc. However, the

greatest challenge will be training future sci-

entists and engineers with the necessary

skills in Power Electronics and attracting

them to the world of Power Electronics.

Noted automotive specialist Prof. Dr.

Ferdinand Dudenhöffer last month stated

that recently proposed EU CO2 emission lim-

its would probably generate 50,000 new jobs

and 9 Billion Euro additional turnover, in the

automotive supply industry. Although these

50,000 new jobs are not all in Power

Electronics, a quite high portion will be and

of those the engineers will have to be there

first, in order to engineer the Power

Electronics answers to the CO2 emission

goals.

And we all know that the number of Power

Electronics engineers graduating in the com-

ing few years not is going to grow, at best

we will be able to avoid decline. This will

become a major stumble block if not

changed and requires immediate action.

What we should do is to take advantage of

the present interest in the environmental

issues and make it clear to present and

future students that if they want to contribute

to saving the world from the negative effects

of CO2 emission a career within Power

Electronics is the right choice.

One good way of doing that is to join forces

through the European Center for Power

Electronics e.V. (ECPE). In this forum most

of the main players in the Power Electronics

business are present from device manufac-

turers over system integrators to OEM’s.

Such a forum has the power necessary to

open all the doors from local authorities to

the top floors in Brussels.

The ECPE is very active in generating coop-

erative R&D projects with universities across

Europe and in spreading Power Electronics

knowledge through frequent training courses

in all aspects of power electronics. If the

ECPE would be just as active in promoting

Power Electronics in media outside of the

Power Electronics circles, I’m sure it would

have a significant impact on the interest for

our industry among potential Power

Electronics engineers.

The big question is what activities can the

ECPE and all of us in the Power Electronics

industry put in place that will attract students

to Power Electronics, make them aware that

the car of the future accelerates quickly and

noiselessly due to Power Electronics, cause

them to understand that the wind turbine is

producing electricity of high quality due to

Power Electronics and that the way to signif-

icant energy savings in industrial environ-

ments, air-conditioning and home appliances

is possible only due to Power Electronics.

Suggestions are very welcome.

http://siliconpower.danfoss.com

G U E S T E D I T O R I A L

10 www.bodospower.comBodo´s Power Systems - April 2007

Power Electronics

Engineers Needed

By Claus Petersen, CEO Danfoss Silicon Power

Input Power4.5V to 5.5V

Isolated DataCommunicationVia SPI or I2C

DCH010505S3kV Isolation 1WDC/DC Converter

Isolated 5V

Instrumentation Amp

Thermocouple

3.3V

Isolation Barrier

INA128

ISO721

ISO721

TPS76333LDO

ADC124424-bitADC

REF3125

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Technology for Innovators and the red/black banner are trademarks of Texas Instruments. 1718A1 © 2007 TI

Applications– Data acquisition

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– Professional audio

– Ground loop elimination

Features– 3kV isolation

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– Up to 78% efficient

– Industry standard SIP-7 package/footprint

– Single or dual output

– UL60950 certified product

– 54 million hour MTBF

POWER MANAGEMENT

Device Input Voltage Output Voltage Output Current (mA)DCH010505S 4.5 to 5.5 5 200DCH010505D 4.5 to 5.5 +5 100DCH010512S 4.5 to 5.5 12 83DCH010512D 4.5 to 5.5 +12 42DCH010515S 4.5 to 5.5 15 67DCH010515D 4.5 to 5.5 +15 33

New DCH01 DC/DC Converters from Texas Instruments

Order samples and download

datasheets now!

GENERAL

As usual a New

Year is facing uncer-

tainties as the emer-

gence of India and

China as well as the

economic power of

the European Union

and Russia call for

changes in the world

order both politically and economically. One

example is the migration of banking busi-

ness from the US to sites abroad as US dis-

closure and immigration laws have been

strengthened. Competition from China is

expected to intensify as “designed in

Europe, made in China” changes to heavier

Chinese involvement in design. On the posi-

tive side a huge Chinese program to

improve its IT infrastructure to cover much of

the country should benefit foreign suppliers.

SEMICONDUCTORS

According to the WSTS global semiconduc-

tor sales grew 9% in December 2006 over

prior year but were down 3.6% sequentially

to $ 21.745 B. All regions gained over prior

year with Asia Pacific up 13.6%, Japan

7.1%, Americas 2.5% and Europe 5.4% (-

2.7% in Euros). Worldwide sales gained

8.9% last year. MEDEA+ chairman recently

claimed that European R&D in nano-elec-

tronics is at world class level. The group’s

long-time office manager Gérard Matheron is

returning to STMicroelectronics to head the

Crolles operation. He is succeeded by Guy

Dubois, also ST while Eberhard Schmid,

Bosch, assumes responsibility for applica-

tions as vice president.

With revenues in excess of $ 1.2 B

International Rectifier is a leader in the

power semiconductor market. About 34% of

its products go into IT applications, 27%

energy efficiency, 15% commodity and 12%

aerospace and defense. Its iMOTIONä inte-

grated design platform reduces energy con-

sumption and allows more features for appli-

ance makers, among others.

STMicroelectronics posted a fourth quarter

net profit of $ 276 M, up from $ 183 M in

2005 but revenue rose only 3.9% to $ 2.48

B and current quarter sales are expected to

decline 3% to 11% sequentially as margins

are to decline to between 34% and 36%

from 36.3% in the previous period partly due

to cheaper mobile phones sold in China and

India by Nokia, its largest customer.

Infineon saw quarter ended December 31,

2006 revenue jump 27% to € 2.13 B and

net profit of € 120 M compared to a prior-

year loss of € 183 M thanks in large part to

the 86% owned memory firm Qimonda which

contributed € 179 M in net profits on sales

up 73% to € 1.17 M due mainly to ASP

increases.

Also optimistic on Europe is Microchip’s

CEO Steve Sanghi who has broadened dis-

tribution coverage via new distributors like

Melchioni in Italy, Anglia in the UK and

Ireland, Burish and Ineltro in Austria, Acal in

the UK, Benelux, Nordic Region and

Rutronik in the same areas plus France and

Spain. A design center was opened in

Rumania last year adding to an existing one

in Switzerland acquired when the firm

bought TelCom Semiconductor in 2001.

Fairchild’s executive VP and GM Functional

Power Dr. Bencuya sees one of his firm’s

strength in application specific integrated

Smart Power Modules featuring multi-chip

packaging technologies. Fairchild has analog

design centers in Korea, China and the US,

is considering a European presence as part

of a plan to reach $ 450 M to $ 500 M in

analog revenue by 2008.

ABB’s Lenzburg, Switzerland, power semi-

conductor operation recently celebrated its

15th anniversary, is focused on IGBTs for

motor controls with no plans to enter the

Intelligent Power Module segment.

AUTOMATION COMPONENTS

EMVA represents the European machine

vision industry and counts as members 79

companies, two research institutes and five

national associations. Activities include con-

ferences, standardization efforts, research

funding and participation at trade fairs such

as Automatica and the Vision Show which

will move to new quarters near the Stuttgart

airport.

Silicon Software received a Vision Award for

its VisualApplets software while Aylesbury

Automation is cooperating in robotics with

Cognex and Omron has opened an

Automation Competence Laboratory in

Istanbul.

Artificial Vision events will be held in Turin

and Vicenza May 17 and May 23 respectively.

PRINTED CIRCUIT BOARDS

PCB equipment supplier HMS Höllmüller is

reported to have opened a plant in Poland,

its fourth while Finland’s Aspocomp is facing

severe profitability problems at its local facility.

Fuba, now controlled by Tunisia’s OneTech,

is producing PCBs in volume in Tunisia while

two German sites specialize in prototypes

and more advanced products.

Electrovac curamic is a producer of ceramic

PCBs for power modules and cooling sys-

tems made in Germany and Austria, supplies

both BMW and Mercedes.

OTHER COMPONENTS

The global switching power supply market is

forecast by Frost & Sullivan to grow to $

15.6 B by next year, up from $ 10.1 B in

2002 with the Greater China region (China,

Taiwan, HongKong) to surpass all others.

Power One’s CEO Bill Yeates believes that

in a few years all power supplies will be digi-

tally controlled with iSuppli seeing DCP as a

means to reduce heat in equipment such as

for telecommunications.Siemens VDO is to

be quoted on the stock exchange with

Siemens however to retain control of the €

10 B, 53 000 staff automotive equipment

maker.Acquisitions include Midcom (trans-

formers) by Wurth Elektronik.

DISTRIBUTION

The fourth quarter 2006 European semicon-

ductor distribution market grew 11.3% over

prior year to € 1.27 B resulting in an annual

growth of 17% to € 5.4 B no doubt exceed-

ing total European semiconductor market

growth, so DMASS. Germany was again the

largest market with a 32% share of the

DMASS total of € 1.7 B, +21.9% followed

by Italy, € 710 M, up 14.5%, UK € 606 M,

+8.6%, France € 496 M, +9.1% and Nordic

+16.1% to € 498 M. Eastern Europe grew

26.9% to € 507 M. Highest annual growth

rates were recorded by Russia, 44.3%,

Czech Republic 33.3%, Denmark 29.9%,

Germany 21.9% and Israel 21.6%. In prod-

uct terms analog increased 21.6% to reach €

1.34 B, 25% of DMASS total while MOS

Micro grew 21.4% to € 1.47 B, DSPs,

SRAMs and other memories had growth

rates of over 30% as had other complex and

design-in intensive products pointing to the

importance of distribution’s role in demand

creation

THE LENNOX REPORT

ELECTRONIC COMPONENTS INDUSTRY

M A R K E T

12 www.bodospower.comBodo´s Power Systems - April 2007

WITH FOCUS ON THE INDUSTRIAL INVERTER MARKET the PrimePACKTM is the

new trendsetter in the medium power range. PrimePACKTM IGBT modules present a spe-

cially optimized concept for integration in modern converters.

Our contribution to your success at the glance:

Improved thermal properties

Low stray inductance

Wide range of operating temperatures

Infineon‘s 1200 V and 1700 V Trench & Field Stop technology

www.infineon.com/PrimePACK

Efficient POWER for your applications

These emerging technologies will enable

standalone micro-sensors and micro-actua-

tors with wireless communications to realize

new and cost-effective system architectures

in a variety of industrial, commercial, medical

and other applications. This means the

demand for lower-power dc-dc

converters/regulators used in these applica-

tions will go up.

The worldwide dc-dc converter/regulator IC

market is projected to grow from 12.3 billion

units in 2006 to 18.6 billion units in 2011, a

compound annualized growth rate (CAGR)

of 8.6%, according to Darnell Group’s latest

analysis of the dc-dc converter market (see

Figure 1).

Low dropout regulators (LDOs) will remain

the largest converter/regulator IC segment

throughout the next five years, increasing

from approximately 7.0 billion to 9.8 billion

units between 2006 and 2011, a CAGR of

7.0%. This was 57% of the market in 2006,

declining to 53% by 2011 (see Figure 2).

The LDO market is growing, but slowly.

LDOs are linear dc-dc voltage regulator ICs

that operate even when the input voltage

barely exceeds the desired output voltage.

Advantages include the ability to extract

“maximum” energy from a battery supply,

simplicity, and low cost. Disadvantages

include low efficiency and limited power-han-

dling capability. They are a less expensive

solution than switching regulators, and they

have lower noise, which makes them suit-

able for RF applications.

LDOs are most commonly found in applica-

tions that require less than 1A. The less-

than-1A segment represents the largest seg-

ment of the dc-dc converter/regulator mar-

ket, at 68% in 2006. Of that figure, sub-

250mA converter/regulators make up more

than half of the unit sales. Lower-power dc-

dc converters/regulators are primarily found

in established applications such as MP3

players, mobile phone handsets, laptop com-

puters, and so on. Over the next five years,

however, growth will be increasingly driven

by a number of emerging ultra-low power

(ULP) wireless applications.

In contrast to today’s portable applications,

ULP devices tend to be “stationary” devices,

such as the sensor and control nodes in

wireless mesh networks (see Figure 3). The

challenges facing ULP wireless mesh net-

works, however, parallel the demands

placed on portable power management,

including the demand for long runtime, bat-

tery and energy source power management,

power efficiency and high levels of integra-

tion.

M A R K E T

14 www.bodospower.comBodo´s Power Systems - April 2007

Low-Power Wireless

to Push DC-DC Converter

& Regulator ICsCost savings is one of the drivers for these technologies

Energy harvesting and low-power wireless technologies (primarily ZigBee™-based mesh networks) could be the “Next Big Thing” that will drive growth opportunities for

power conversion and power management.

By Linnea Brush, Senior Research Analyst, Darnell Group

Figure 1 – Worldwide DC-DC Converter/Regulator IC Market, by Amperage

1,000

2,000

3,000

4,000

5,000

6,000

7,000

<250mA 250-500mA 500mA-1A 1-3A 3-5A 5-10A >10A

2006 2011

Mill

ion

so

fU

nit

s

Figure 2 – Worldwide DC-DC Converter/Regulator IC Market, Unit Market Share

Unit Sales

LDO57% 53%Switching

Regulator 39%

SwitchingRegulator

44%

Charge Pump3% Charge Pump

4%

© National Semiconductor Corporation, 2007. National Semiconductor and are registered trademarks of National Semiconductor Corporation. All rights reserved.

LP3878 – 18 µV Noise, Stable with Ceramic or Tantalum Capacitors

Low-Noise LDOs Power Noise-Sensitive Analog Loads

Frequency (Hz)

1

0.1

0.01

Noi

se (µ

V/ H

z)

10010 1K 10K 100K

LP3878S/D

IN OUT

ADJBYP GND

0.01 µF

4.7 µF

S/D

1kΩ

GND

10 µF

1.8 VOUT

TP5

2.5 to 16 VIN

33 nF80Ω

LP3878 Typical Application Circuit Output Noise vs. Frequency

Power Designer

Expert tips, tricks, and techniques for powerful designs. Sign up today at

power.national.com/designer

For samples, datasheets, online design tools, and more on LDOs, visit us today at: ldo.national.com

Phone: +44 (0) 870 240 21 71Email: europe.support@nsc.com

Applications: Ideal for low-noise amplifiers, voltage controlled oscillators, RF receivers, medical instrumentation,automated test equipment, and measurement devices.

Product ID VIN VOUT Load Output Noise Package

LP3878 2.5V to 16V ADJ (1.0 to 5.5V) 800 mA 18 µV PSOP-8, LLP-8

LP3879 2.5V to 6V 1.0, 1.2V 800 mA 18 µV PSOP-8, LLP-8

LP5900 2.5V to 5.5V 1.5V to 3.3V 100 mA 6.5 µV micro SMD-4, LLP-6

Power Management

Design Seminars

April 25 – May 16

www.national.com/euseminars

16 www.bodospower.comBodo´s Power Systems - April 2007

Examples of mesh network applications

include medical sensors/monitors, home and

building automation, and military applica-

tions. Radio frequency identification (RIFD)

tags fit into both the portable and ULP con-

text. Further in the future, so-called “smart

dust” or “wireless motes” are expected to

contribute significant growth opportunities.

Cost savings is one of the drivers for these

emerging technologies. Copper wiring is

increasingly expensive. The latest wireless

networking systems promise substantial sav-

ings and improved performance compared

with traditional wired alternatives. For exam-

ple, use of piezoelectric-based energy har-

vesting ULP wireless lighting control in a

recently built warehouse saved over 70% in

construction costs compared with the equiva-

lent wired solution, and reduced construction

time.

Industrial/commercial buildings are a good

opportunity for wireless lighting sensors and

control, with tax incentives and energy sav-

ings contributing to this trend. According to

the New Buildings Institute, lighting controls

can reduce lighting energy consumption by

50% in existing buildings and by at least

35% in new construction. Industrial lighting

control is one application where the opportu-

nities appear to be in new construction rather

than retrofits, at least in non-residential appli-

cations such as library, retail, hospital, gov-

ernment, recreational and industrial facilities.

A survey from Ducker Research found that

nearly 80% of new construction projects

completed by respondents over the previous

two years featured automated lighting con-

trols, while less than half of retrofit projects

included them.

Advanced ULP wireless systems will incorpo-

rate various combinations of thin-film batter-

ies, micro-electromechanical systems

(MEMS), wireless sensors, low-power micro-

controllers, and other advanced components.

Energy harvesting, energy storage and

power management, including larger num-

bers of dc-dc converter/regulator ICs, are

some of the leading opportunities in terms of

the commercial rollout of next-generation

ULP systems. As a result of the rise of these

ULP systems, the sub-250mA segment will

grow, with the specific growth opportunity

being significantly below the 250mA cutoff.

Companies and research groups are still

defining “energy harvesting” in different

ways. In general, energy harvesting is the

process by which energy is captured and

stored. Potential energy sources include

light, vibration, thermal gradients, pressure

differential, motion and piezoelectric (from

manual depression of push-button switch).

Energy harvesting is getting increased atten-

tion in wireless mesh network applications

due to the problems with batteries. With mil-

lions of wireless sensors expected to be

deployed in the next decade, replacement of

millions of batteries (or entire sensor units)

presents a major expense, especially for

embedded sensors and sensors that are not

easily accessible.

Wireless sensor networks are getting more

complex, also, placing greater demands on

the batteries. The need to access more data,

more frequently; in situ processing and

analysis; hard-to-reach locations or where it

would be too costly to replace large numbers

of batteries; these are the situations where

energy harvesting could provide value. One

power supply company has said, “If anyone

gets a reasonable power density from an

energy harvesting device that can operate in

an industrial temperature range, they will win

big.” Another company believes that while

energy harvesting costs a few dollars more

than battery-powered versions today, they

should be comparable in cost by 2008 or

2009. Batteries are problematic for large-

scale wireless applications. Today’s cost pre-

mium is typically below what it costs to swap

the battery one at a time, including battery

cost, labor and so on. Over an expected life-

time of 15 years, a self-powered sensor

could provide “significant” cost savings.

Is there an ideal energy source for wireless

sensors? Will power management or energy

harvesting provide the biggest breakthrough

for low-power systems? These questions will

be explored at the nanoPower Forum in San

Jose, California, June 4-6, 2007. Business

models usually determine the success of any

market, so pricing, product roadmaps, and

traction of existing technologies will be cru-

cial for companies who recognize ULP’s

breakthrough potential.

www.darnell.com/converters.php

M A R K E T

Figure 3 – Wireless Mesh Network Model

18 www.bodospower.comBodo´s Power Systems - April 2007

Bodo Arlt: What end markets will drive

Power Management technology?

Don Paulus: Linear Technology is engaged

in a broad range of end markets, including

networking and communications infrastruc-

ture, computing, industrial/medical, automo-

tive, avionics and aerospace, and digital

consumer. Each end market brings its own

challenges that drive power management

technology. In particular, we are excited

about increasingly demanding applications in

the automotive sector driven by growth in

electronics systems ranging from advanced

telematics and entertainment to solid state

lighting to sophisticated ‘x-by-wire’ drive train

and body control.

Bodo Arlt: What is Linear Technology’s

position besides the wide range of discretes

and the selected modules?

Don Paulus: Linear Technology has main-

tained a singular focus on high performance

analog ICs since our founding 25 years ago.

Our culture of continuous innovation and

technical leadership has led to a broad port-

folio of leading edge products including lin-

ear and switching DC/DC converters, battery

chargers, LED and photoflash drivers, and

display bias generators. Increasingly we are

combining multiple functions into highly inte-

grated ICs that provide all of the high per-

formance power management functions

required for the application. Recently we

have championed the introduction of multi-

chip microModule power supplies that pro-

vide complete DC/DC subsystems in an IC-

like form factor to address high reliability and

other space-constrained applications.

BodoArlt: What are the technologies that

can offer innovation for leadership?

Don Paulus: Linear Technology has always

been a design-driven company. We believe

that world class design is a key determinant

of innovation in high performance analog

products, and we pride ourselves in main-

taining the finest design team in the industry.

In addition, since we are a vertically integrat-

ed company, Linear Technology is able to

tailor a variety of specialized technologies to

achieve optimum analog performance,

including CMOS, BiCMOS, DMOS and

Bipolar processes. We supplement these

core strengths with in-house assembly and

test operations to deliver outstanding value

to our customers.

Bodo Arlt: Is it more in silicon, or is it part of

packaging technology?

Don Paulus: In power management, pack-

age technology is increasingly important. In

particular, the ability to deliver high power

density and excellent thermal characteristics

are key to product performance and reliabili-

ty. At Linear Technology, our design team

works side by side with in-house package

engineering as well as outside suppliers to

provide direction and feedback regarding the

technologies needed to support our next

generation designs. Further, while test tech-

nology is often overlooked, it too is an impor-

tant factor in our ability to deliver industry-

leading products. Our many years of experi-

ence in developing high performance test

solutions constitutes another competitive

strength of Linear Technology.

Bodo Arlt: What makes Linear Technology

different from traditional IC suppliers?

Don Paulus: Linear Technology differs from

other suppliers in a number of respects.

First, as I mentioned previously, we have a

disciplined focus on high performance ana-

log ICs. So we have optimized and targeted

the company to serve this special market

segment, and we are careful to avoid prod-

ucts and markets that do not leverage the

performance we bring. Second, we are an

engineering-driven company in that the

strategic marketing and product planning

functions rest with design engineering. We

develop long term relationships with key cus-

tomers and put senior designers and design

managers into the field continuously in order

to sleuth out impending trends and to quickly

translate them into new products that will

V I P I N T E R V I E W

Interview on Power

Management Technology

with Donald E. Paulus, Vice President and General Manager, Power Products, Linear Technology

By Bodo Arlt, Editor BPSD

Don Paulus

Vice President and General Manager, Power Management

ProductsLinear Technology Corporation

Mr. Paulus has served as Vice President and General

Manager of Power Management Products since 2003, and

has been with Linear Technology since 2001, initially as

Director, Satellite Design Centers. Prior to joining Linear

Technology, he was a founder of Integrated Sensor

Solutions, Inc. (ISS), serving as Vice President of

Engineering and Chief Operating Officer from 1990 to

1999. Following the acquisition of ISS in 1999 by Texas

Instruments, Mr. Paulus served as TI’s General Manager,

Automotive Sensors and Controls until 2001. Prior to ISS, Mr. Paulus held various engi-

neering and management positions with Sierra Semiconductor, Honeywell Signal

Processing Technologies and Bell Laboratories. Mr. Paulus holds a BS in Electrical

Engineering from Lehigh University, an MS in Electrical Engineering from Stanford

University and an MBA from the University of Colorado.

19www.bodospower.com

V I P I N T E R V I E W

enable next-generation customer applica-

tions. And third, our goal is to be the suppli-

er of choice for high performance analog

across our broad customer base, both large

and small. So we complement our products

with the industry’s best quality and shortest

production leadtimes and service our cus-

tomers with a highly technical direct sales

and applications team leveraged by strong

distribution partners in every major market

worldwide.

Bodo Arlt: How much is Linear Technology

involved in the end customer’s application?

Don Paulus: Often very involved. Power

management is a very applications-intensive

business, and system cost and performance

are dictated by factors ranging from choice

of system architecture to component selec-

tion and board layout. But power expertise

is increasingly limited, even at large systems

companies. So the Linear Technology appli-

cations team provides a variety of tools to

support our customers, including circuit sim-

ulators, product macromodels and related

design tools, demonstration circuits and lay-

outs, as well as direct design and problem

solving support.

Bodo Arlt: How much is Linear Technology

involved in motion applications using the

advantage of high voltage IC technologies?

Don Paulus: Our in-house process tech-

nologies, both Bipolar and MOS-based,

support voltages from less than 1V to more

than 100V. These processes enable a wide

range of applications that demand these

voltage extremes. In particular, the trans-

portation industry is an important target mar-

ket, with tough requirements to support cold

crank and load dump transients while provid-

ing clean power to sensitive digital ICs with

high efficiency over a wide range of load

conditions. Similarly, selected industrial

applications, including process control,

instrumentation and robotics value the same

high voltage capabilities.

Bodo Arlt: What will be the target to intro-

duce new products?

Don Paulus: New products are the life

blood of Linear Technology. We have more

than 7000 products in our portfolio and we

do not obsolete them; we still sell products

today that were introduced to the market

almost 25 years ago. This year we will intro-

duce over 200 new products, with power

management representing more than half of

that total. Further, instead of investing

development resources on cost reduction

efforts, we focus on new products that will

extend the state of the art in performance or

functionality, thereby providing system lever-

age for our customers.

Bodo Arlt: What will be the future for line

voltage and driver technology in Linear

Technology?

Don Paulus: In the networking and commu-

nications infrastructure markets we see a

continuing trend away from multiple output

AC/DC converters toward intermediate bus

architectures which in turn drive the need for

high performance point of load regulators to

service the continuing proliferation of low

voltage (sub-5V) power rails. At the same

time, many applications demand wide input

voltage capability to accommodate multiple

input power sources. Increasingly even

portable products must be compatible with

power sources as diverse as single cell lithi-

um batteries, USB ports, AC wall adapters

and automotive power ports. Linear

Technology offers a very broad product line

to address these diverse market needs.

Bodo Arlt: Do we expect more monolithic

solutions in power management?

Don Paulus: I believe that monolithic solu-

tions will be attractive to more and more cus-

tomers. Products with integrated power

devices and synchronous rectification pro-

vide superior performance and power densi-

ty while simplifying the power system design

task. Integrated subsystem products, like

Linear Technology’s microModule product

line go a step further, providing ‘turnkey’

solutions that bring high performance power

system design within the reach of digital and

systems designers. But in the hands of a

power design expert, discrete designs utiliz-

ing state of the art controllers and separate

power stages may still offer the most flexible

and cost-effective solutions. As a result,

Linear Technology offers a full range of prod-

ucts with complexity ranging from simple

DC/DC controllers to complete microModule

power subsystems.

Bodo Arlt: Who are your competitors you

believe will stimulate the race for leadership?

Don Paulus: We face different competitors

in different markets. In the digital consumer

market, for example, there are a number of

companies that offer single function power

management products with minimally

acceptable performance at very low prices.

At the other extreme, a different set of com-

panies provides highly customized solutions

with resultant compromises between solution

size, complexity and performance. Linear

Technology has chosen a unique path,

focusing on the high performance power

needs of targeted applications, and meeting

those needs with elegant, highly integrated

standard products. In the automotive mar-

ket, on the other hand, we face a different,

much smaller number of established com-

petitors who also have the necessary infra-

structure and global presence to overcome

the significant barriers to entry. Here

Linear’s quality focus, culture of continuous

improvement and in-house operations are

important assets, complementing our design

innovation and applications know-how.

Finally, in the broad industrial market we dif-

ferentiate ourselves from a large set of com-

petitors through product performance and

our strong technical field sales and applica-

tions support.

Bodo Arlt: Are you ready for 2007?

Don Paulus: Absolutely. Over the past two

years, Linear Technology has made major

investments in our design and sales organi-

zations. In design, we have increased our

staff by more than 30%, including three new

design centers in Phoenix and Dallas and

our first European design center in Munich.

Our expanded design capability will translate

to an acceleration of new product introduc-

tions throughout 2007. Further, our growing

geographic presence will enable us to stay

even closer to our customers and to more

quickly address their rapidly changing

needs. Our larger sales and field applica-

tions force enables more focused support for

our larger customers, as well as a greater

reach to our broad base of smaller cus-

tomers worldwide. After a relatively slow

second half of 2006, we believe that we are

well positioned for a very successful 2007.

Bodo Arlt: Thank you Don for the time and

we look forward to a successful future for

power management technology.

www.linear.com

Variable-speed intelligent pumps are rapidly

gaining favour in applications as diverse as

chemical processing and building services.

The growing demand for these pumps is

largely due to efficiency improvements over

conventional fixed-speed ‘on/off’ designs.

Companies find that using intelligent pumps

to improve efficiency helps them comply with

environmental legislation and also leads to

operating-cost reductions.

Traditional fixed-speed pumps always work

at full capacity. Variable-speed systems

match pump speed to demand. The pump-

drive circuitry need only supply the power

necessary to satisfy the system’s instanta-

neous demands. Designers can choose

smaller, lighter, less expensive pumps while

customers benefit from the fact that a pump

that operates most often at a fraction of its

full capacity is inherently more reliable.

Water and wastewater management and

building automation are typical target appli-

cations for intelligent pumps. They are sensi-

tive to operating costs and are commonly

subject to Governmental control. Building

regulations and other legislation designed to

address environmental concerns, such as

the UK Government’s Code for Sustainable

Homes are influential in these applications.

Intelligent pumps can contribute most in sys-

tems with widely fluctuating fluid demand or

narrow-ranging pressure requirements over

a wide range of flow rates. An example is

the system supplying chilled water in an

office building’s heating and cooling system.

Estimates suggest that a variable-speed

pump can reduce energy consumption in

such systems by 30 to 70% (ARC Advisory

Group Intelligent Pump Market Analysis).

In these applications, however, energy effi-

ciency and cost of ownership tell only a part

of the story. Just as important is the need to

keep acoustic noise as low as possible.

Moreover, such applications often require

fast response times and high control accura-

cy to accommodate the full range of flow

requirements and to quickly match supply

with demand. All of this increases the com-

plexity of controlling the PMSMs (perma-

nent-magnet synchronous motors) at the

heart of intelligent-pumping designs.

A PMSM controller must sense or calculate

both the rotor angle and speed. The tradi-

tional method of detecting these parameters

uses external components such as Hall-

effect sensors. Such sensors require addi-

tional circuitry, however, adding to the sys-

tem cost. Sensor-based designs are also

less reliable than sensorless alternatives —

a fact that is exacerbated by the environ-

ment in which the motors operate.

Consequently, more designers are looking

towards sensorless PMSM-control schemes

for intelligent-pumping deployments.

Sensorless control

Historically, however, designing a sensorless

PMSM controller has been a challenge for

pump-system OEMs. The most straightfor-

ward method measures the motor-winding

currents and derives estimates of the rotor’s

position and speed. Direct measurements of

motor-phase currents are expensive to

C O V E R S T O R Y

20 www.bodospower.comBodo´s Power Systems - April 2007

Smart Pumping:

Motion-Control Advancements

Aid Intelligent-Pumping

Applications

Sinusoidal current control ensures quiet operation

The latest motion-control semiconductor technologies help designers rapidly implement intelligent-pump controls.

By Aengus Murray, International Rectifier

Figure 1: International Rectifier’s iMOTION platform includes a digital motor controller, a cur-rent sensor, and a three-phase power stage.

implement and, in general aren’t economic for many commercial

intelligent-pump applications. Cost-effective sensorless designs

make position and speed calculations based on an indirect current

measurement. The controller computes the motor-winding currents

from this indirect measurement and derives the rotor speed and

torque from the winding-current calculations.

Though practical in terms of implementation, sensorless pump con-

trollers until recently have required the design team to combine

pumping-systems knowledge, control algorithms expertise, and

advanced programming abilities. The latter are often unavailable in

house. Even when the requisite system-development skill set exists

in-house, writing and testing the complex code can increase design

risk, cost, and cycle time.

The need to quickly and cost-effectively build control systems for

PMSMs has created a demand for dedicated ICs that can imple-

ment sensorless control. Semiconductor manufacturers such as

International Rectifier have developed motor-control platforms com-

prising building blocks that OEM designers can quickly bring togeth-

er to create a finished variable-speed, sensorless drive design.

International Rectifier’s iMOTIONTM platform, for example, is based

on digital motor controllers running PMSM-control algorithms, cur-

rent sensing ICs, and power modules (Figure 1). Platforms such as

these accelerate the design process, cut component count, reduce

risk, and lower project costs.

Dedicated intelligent pump platform

International Rectifier’s latest iMOTION development is a platform

that delivers quieter operation and higher efficiency to PMSM-based

intelligent-pumping applications with power requirements up to 300

W. Combining IR’s mixed-signal motion-control IC with an intelligent

power module (IPM) such as the IRAMS06UP60B, engineers can

now rapidly develop a sensorless PMSM-control system for smart

pumps. This system achieves higher performance and reliability

than alternative discrete. Sinusoidal current control ensures quiet

operation while delivering the efficiency benefits of a PWM-based

design. Additionally, the control IC also enables smooth pump start-

up.

The IRMCF371 combines IR’s proprietary MCE (Motion-Control

Engine) with all of the control and analogue interface functions nec-

essary for accurate, sensorless, sinusoidal control of PMSMs using

DC link-current measurements (Figure 2). These include a differential

amplifier, dual sample-and-hold circuits, and a 12-bit ADC. Pre-

defined hardware blocks implement key sensorless-control-algorithm

components such as an angle estimator. The controller IC also fea-

tures an integrated 60-MIPS, 8-bit, 8051 microcontroller, which oper-

ates independently from the MCE to execute application-layer func-

tions.

The IRAMS06UP60B is a compact, intelligent, motor-driver power

module in an isolated package. The module includes short-circuit-

rated IGBTs, the measurement shunt, over-temperature and over-cur-

rent protection, under-voltage lockout. Integrated bootstrap diodes for

the high-side driver and single-supply operation simplify the pump-

control circuitry.

Pump motor control operation

The control IC’s ADC samples the low-voltage signal across the

power module’s DC-link shunt. The MCE’s algorithm reconstructs the

motor-winding currents from the samples. During two inverter-switch-

ing states the current flowing in the DC bus matches the current in a

motor winding. The controller measures two of the three motor-phase

currents by sampling twice within each PWM cycle. The three phase

currents sum to zero so the algorithm calculates the third current

from the two measurements. A Clarke transform converts the three-

phase current data into an equivalent two-phase dataset. A rotor-

angle estimator uses the two-phase current data and voltage values

from a forward vector-rotation block to calculate the rotor angle and

speed.

An FOC (field-oriented control) algorithm transforms the AC motor

winding currents into two DC components representing torque (IQ)

and flux (ID). This transform simplifies the controller design because

the current-loop tuning becomes independent of the motor speed.

The outer speed loop calculates the torque-reference command for

the IQ loop based on the speed error. There is a RAMP function at

the speed loop’s input, which limits acceleration to specified limits,

and a LIMIT function on the output to limit the motor current. An addi-

tional control function introduces phase advance to maximise the

torque output when driving an IPM (interior permanent-magnet)

motor.

21www.bodospower.com Bodo´s Power Systems - April 2007

C O V E R S T O R Y

www.electrovac.com

Your solution for high power density and extreme environmental conditions

DBC Substrates for power convertersand intelligent power modules

Moisture-proof casings for sensors,airbag release systems and optoelectronic components

22 www.bodospower.comBodo´s Power Systems - April 2007

Motion control programming

A graphical-compiler tool integrated into the

MATLAB/Simulink™ development environ-

ment facilitates programming the MCE. The

graphical programming method reduces

design errors and promotes quick design

cycles. The developer selects functions from

the available MCE-control elements includ-

ing proportional plus integral, vector rotator,

angle estimator, multiply/divide, low-loss low-

EMI space vector PWM, and single-shunt

IFB. The developer then uses the compiler

to link the functions together (Figure 3).

The 8051 8-bit microcontroller executes

sequencing, user interface, host communica-

tion, and upper-layer-control tasks. The

microcontroller includes a JTAG port for

emulation and debugging. The configurable

nature of the MCE also makes the iMotion

platform highly flexible for implementing vari-

ous control strategies or product variations

on a hardware set.

www.irf.com

www.irf.com/product-info/imotion

C O V E R S T O R Y

Figure 2: The IRMCF371 implements an FOC (field-oriented control) algorithm for intelligent pump control.

Figure 3: The iMOTION graphical programming environment promotes quick, error-freedesign cycles.

24 www.bodospower.comBodo´s Power Systems - April 2007

Major applications for IGBT modules are

power converters for traction and industrial

applications. In these converters the power

devices are used to modulate a voltage with

respect to its frequency and magnitude. The

applicable voltages and currents of IGBT

modules range from 600V to 6.5kV and

some tens to several thousands of Amperes.

In this article we will focus mainly on high

power modules with Cu baseplates for

industrial applications. Such modules usually

contain several IGBTs and diodes, which are

mounted onto a metallized ceramic substrate

(e.g. Al2O3 with Cu metallization).

Depending on the power classification of the

modules, up to nine substrates are mounted

into one housing on a baseplate and are

electrically wired. The most common pack-

aging technology for the substrate-to-base-

plate interconnection is the use of soft-solder

joints. In operation, due to thermal power

losses in the semiconductor components,

local temperature cycles occur and result in

high thermal stresses within the adjacent

wire bonds as well as the metal and solder

layers. Due to the large differences in the

coefficients of thermal expansion (CTE) of

the connected materials, these stresses

result in thermo-mechanical strain inside the

solder layers. Solder fatigue caused by the

periodic straining of the interconnection layer

leads to the formation and propagation of

cracks within the solder volume. As a result,

the interconnected partners delaminate with

increasing number of thermal cycles. The

delamination of the substrate from the base-

plate will increase the overall thermal resist-

ance between chip and heat sink. As a

result, the reliability of these solder connec-

tions is a restricting parameter for the long

term reliability of modules with Cu base-

plates. A simple but expensive way to

improve the thermal cycling capability is to

match the coefficient of thermal expansion

(CTE) of the interconnected materials. This

fact triggered the introduction of AlSiC base-

plates for traction applications.

Figure 1 shows the result of a comparative

thermal cycling (TC) test of Cu plus Al2O3

substrate versus AlSiC plus AlN substrate.

While no delamination can be observed after

20.000 cycles for the AlSiC baseplate,

severe delaminations occurred in the Cu

module already after 4.000 cycles.

Although AlSiC closely matches the CTE of

the substrate, its price ratio to copper of

approx. 3-4 to 1 limits its introduction to less

cost oriented product groups. To avoid the

high costs involved with AlSiC or equivalent

solutions like CuMo sandwich designs or

CuC baseplates Infineon has worked inten-

sively on an improvement of the solder

process for copper baseplate modules.

As a test procedure for the resistance to sol-

der fatigue in the substrate-to-baseplate

joint, the so-called thermal cycling test is

applied. A cyclic thermal power is induced

into the bottom side of the module by exter-

nal heating and cooling of a hot/coldplate.

The delamination of the substrate can be

monitored by means of ultrasonic imaging

(USM) and Rth measurements. A deeper

insight into the formation and propagation of

cracks can be obtained by the analysis of

cross sectional images via optical or electron

microscopy.

Thermal cycling results

There are two different strategies to test the

mechanical reliability of IGBT power mod-

ules. In both cases the modules are subject-

ed to temperature cycling between a mini-

mum and maximum temperature. In case of

a power cycling test (PC) a cyclic current is

applied to the module. The power losses of

the semiconductor components create cyclic

heat fluctuations which lead to thermal fluc-

tuations within the adjacent layers. In con-

trast to this, the thermal cycling test (TC)

I G B T M O D U L E S

Improving the Thermal Cycling

Capability of Cu Baseplate

Modules

Homogeneous solder layer even exceeds the impact of the solder material

Due to power losses as well as alternating external operating conditions in IGBT powermodules thermomechanical strain arises from the different coefficients of thermal expan-sion. Especially for the solder layers of Cu baseplates this cyclic straining leads to the

formation and propagation of cracks. As a result, the thermal resistance between chip andheat sink increases with increasing number of cycles. The influence of various design andmaterial parameters on the long term reliability of large area solder joints is discussed.

By K. Guth and Th. Schütze; Infineon Technologies AG, Germany

Figure 1: Thermal cycling test of standard(Cu-Al2O3) and traction modules (AlSiC-AlN). Functional joint area in bright grey anddelaminated area in red.

25www.bodospower.com Bodo´s Power Systems - April 2007

I G B T M O D U L E S

exposes modules to temperature cycles

which are externally generated by a hot/cold-

plate. In this case, heat is not generated

actively inside the module but by the exter-

nal hot/cold-plate. Due to longer cycling

times a homogeneous temperature distribu-

tion is reached inside the module.

Since the focus of our investigations was on

the solder fatigue, the TC test is a very suit-

able test procedure since it stresses the sub-

strate-to-baseplate joint more effectively than

a PC or a thermal shock test. Figure 2 dis-

plays a schematic cross-sectional overview

of a typical module mounted onto a hot/cold

plate while Figure 3 shows a representative

temperature profile.

Solder layer homogeneity and thickness

In TC tests it has been found, that the

delamination usually starts inhomogeneously

from one substrate edge only. This is due to

inhomogeneities in the solder thickness (see

Figure 4a). Based on this observation the

solder process was improved by the intro-

duction of spacers. Figure 4b shows an

image of an ultrasonic measurement from a

substrate-to-baseplate connection of a mod-

ule in spacer technology which has been

exposed to the same TC test as the module

in Figure 4a. While up to 45% of the solder

layer has already delaminated in the module

without spacers, the delamination in the

module with spacers is a mere 10%. The

cycling capability will increase correspond-

ingly.

Solder material

Due to the RoHS/WEEE EU-directive great

effort has been directed towards the intro-

duction of new lead-free solders. In this con-

text a variety of different solder materials has

been analysed with regard to their TC per-

formance. SnAg3.5 solder which is used for

medium power modules shows the best per-

formance of all tested materials. Figure 5

summarizes the results.

Substrate layout and material

Beside the solder material and its geometric

layout, the substrate offers additional

improvement potential. While substrate

material and layer thicknesses are obvious

influence parameters, the layout of top and

bottom side copper is often neglected. The

influence of the top side copper layout on

delamination is indeed insignificant, but its

influence on the increase of thermal resist-

ance for the power semiconductors has to

be considered. Interestingly, the design of

the copper layer on the bottom side can

directly influence the delamination. The aim

of the bottom side layout should be a reduc-

tion of the mechanical stress induced into

the corners of the solder connection. A way

to reduce this stress is to extend the bottom

side copper over the edges of the actual

ceramic material of the substrate (Figure 6).

The decoupling of the bottom copper metal-

lization from the Al2O3 ceramic leads to a

decelerated crack formation and propagation

within the solder layer (Figure 7).

Interestingly, the crack formation position for

the new substrate is not the outer edge of

the bottom Cu metallization (see Figure 6a).

Summary

Solder material and thickness are the key

factors influencing the quality of a solder

joint. Our experiments revealed that the

impact of a homogeneous solder layer even

exceeds the impact of the solder material.

Furthermore a new layout of the bottom sub-

strate metallization can drastically improve

the TC performance. Experiments show that

it is possible to reduce the delamination by a

factor of 3 to less than 10% for 10.000 ther-

mal cycles with a substrate whose outer

regions match the CTE of the baseplate.

www.ifineon.com

Figure 2: Cross-section of a module mount-ed onto a hot/cold plate in a thermal cyclingtest.

Figure 4: USM image of the substrate-to-baseplate delamination after 8.000 thermalcycles. (a) Inhomogeneous de-laminationwithout the use of spacers. (b) More homo-geneous delamination due the use of spac-ers.

Figure 6: Reduced delamination by the useof an enlarged Cu metallization on the bot-tom side of the substrate. All substrates aresoldered to Cu base-plates, which are notshown in the images.

Figure 3: Temperature profile of a TC testwith a swing of DT=80K and a cycle time of5 minutes.

Figure 5: Delaminated area after TC vs.number of cycles for different solder alloys(DT=80K).

Figure 7: Delamination vs. number of cyclesfor the two different substrate layouts fromFig. 6.

Most of the LED drivers in the past were

based on some sort of charge pump, where

the input voltage was multiplied by 2x and

the LED voltage was post regulated by same

sort of internal low dropout regulator.

Some high-power LEDs require much higher

current before they start emitting light; there-

fore, most of the current industry standard

LED drivers are based on boost topology

since the current can be up to a few amps.

For handheld applications such as cell

phones and PDAs, which are powered by

battery, system manufacturers require the

LED drivers to provide some sort of dimming

function. The reason for this is that battery

life is inversely proportional to light intensity,

and light intensity is directly proportional to

LED current. The simplest technique that

chip vendors have adopted is to provide an

EN pin that turns-on the boost regulator

when the voltage is above a certain thresh-

old; otherwise, it shuts-off. Since most of

these handheld applications use a micro-

processor or a microcontroller, it is very easy

to generate a rectangular pulse of a certain

frequency, amplitude and duty-cycle. If you

apply this PWM signal to the EN pin, one

can increase or decrease the LED current by

varying the duty cycle. So by increasing the

duty-cycle, you force more current into the

LED and it looks brighter compared to

decreasing the duty-cycle, where you force

less current into the LED, and it looks dim-

mer. This simple approach works very well

for dimming the LEDs, but it injects high rip-

ple current on the input supply, and in some

systems this is not acceptable since it drags

the input supply voltage down. See Figure 1,

which show the input supply current when

the LED current is reduced from 700mA to

350mA by using a 3V, 10 KHz, 50% duty

cycle PWM signal on the EN pin. This figure

shows that the peak-to-peak input ripple cur-

rent is approximately 3A, which is too high.

O P T O

26 www.bodospower.comBodo´s Power Systems - April 2007

Simple Technique for LED

Driver Applications

Minimizing input supply ripple current

LED applications in the consumer market have really taken off like a wild mushroom. In the past they were very popular in cell phone applications, but now you find them in:

home lighting applications, airplane cabin lights, automotive headlights, MP3 players, etc.

By Ajmal Godil, Intersil

Figure 1: Top is an input supply ripple current of approximately 3A pk-pk: Bottom is a PWMsignal used for reducing LED current from 700mA to 350mA.

Figure 2: EL7801 schematic for reducing input supply ripple current for dimming

VDC 1

VHI 2

OVP 3

SWD1 4

SWD2 5

BO

OST

/BU

CK

6

LE

VE

L7

TE

MP

8

FB9

TM

AX

10

SWS111

SWS112

EN/PWM13

MODE14

ENL15

VB

AT

16

NC

17

GN

D18

FAU

LT

19

VI N

20

U1EL7801

J1

5Vin C10.1uF

C210uF

L110uH

D2MBR140

C947n/50V

R11

0.2 Ohms

C51u

C80.1u/25V

R210

+ C1122U/50V

C40.1u/25V

D1LED

D3LED

D4LED

D5LED

D6LED

D7LED

D8LED

D9LED

R35k

R1

20k

R4

20K C30.1uF

PWM Signal, 5V 10KHz, 6% Duty Cycle175mV corresponds to 350 mA LED current

The circuit in Figure 2 addresses this issue

by using the Intersil’s EL7801 boost LED

driver that not only offers the “EN” pin but

also provides a “Level” pin. A DC voltage on

this pin controls the LED current. This circuit

also uses a 10 KHz PWM signal, but rather

than feeding it to the EN pin, one can mini-

mize the input supply peak-to-peak ripple

current by passing this PWM signal through

a low-pass RC filter (R4 and C3) with a time

constant of 2mS. This low-pass filter with a

time constant >> 1/Freq._PWM would pro-

duce an average voltage that can be con-

nected directly to the “Level” pin to control

the LED current. So a 5V, 50% duty-cycle

waveform would produce 2.5V waveform,

which after internal level shifting would cor-

respond to 500mV on the Level pin. The

average voltage for the level pin can be cal-

culated by the formula below:

Vavg_Level_Pin

= (PWM_Amplitude *Duty Cycle)*0.2

Iavg_LED = Vavg_Level_Pin / R11

(R11 in Figure 2 is 0.2 ohms)

Figure 3 shows the input supply ripple cur-

rent under the same test conditions by

reducing the LED current from 700mA to

350mA. It can be seen that the input ripple

current has been reduced to a negligible

level.

www.intersil.com

O P T O

27www.bodospower.com Bodo´s Power Systems - April 2007

Figure 3: Input supply ripple current for schematic in Figure 2 reduced to approximately 50µV.

28 www.bodospower.comBodo´s Power Systems - April 2007

Although ferrite materials had been well

known for years, their poor performance in

terms of saturation level and magnetic per-

meability did not allow their use at frequen-

cies as low as 50/60Hz. However, recent

developments have revolutionised the use of

ferrites at these frequencies, bringing many

advantages to a wide range of applications,

including the fast growing energy efficiency

market.

The use of a new type of ferrite with

improved magnetic permeability allows split-

core current transformers to perform accu-

rate measurement of AC signals in an

extended frequency range that includes

50/60Hz. The ferrite core provides high

accuracy and excellent linearity even at very

low current levels, and the transformers

have a particularly low phase-shift between

measured voltage and current. The hard and

dense core allows very small air gaps to be

achieved and is virtually insensitive to age-

ing and temperature changes, in contrast to

other materials, such as FeSi or FeNi.

The principal change in these new ferrite

families is that the permeability has been

improved, to such an extent that 50/60 Hz

current transformers can now use it in the

same way as FeSi or FeNi cores, despite

the magnetic saturation level remaining low.

This unlocks the other features of ferrites,

which until now have been unavailable to

50/60Hz applications because of the perme-

ability problem:

• Excellent linearity even at very low levels

• Hardness, allowing very small air gaps

• Large frequency range due to low loss

level

• Low cost

Until now, the best materials for split-core

current transformers have been FeNi (best

performance but high price) and FeSi (best

price but poor performance). The new high-

permeability ferrite offers the best of both

worlds, thanks to the above features.

The accurate measurement of true active

power or energy introduces specific require-

ments:

• Low phase shift between measured volt-

age and current

• High linearity of the analogue sensing

part, especially at low current levels

• Easy-to-install device such as split core

current transformers

and all that at an attractive price, of course.

The high-permeability ferrite material does

not give the best results in solid-core current

transformers, so let us focus on split-core

current transformers. The hardness of the

solid material (consider ferrite as a ceramic)

allows very fine machining, providing air

gaps down to a few microns that are stable

over many years. Laminated materials such

as FeSi or FeNi do not allow air gaps better

than 20 or 30 microns, and these are more

sensitive to ageing and temperature

changes. If this is added to the better lineari-

ty of the ferrite at low magnetic excitation

(i.e. for low current), the ferrite offers a bet-

ter performance than FeNi-80%, and a

lower cost.

Figures 1, 2 and 3 are extracts from simula-

tion comparing the phase shift behaviour of

FeSi, FeNi and high-permeability ferrite in a

5A current transformer.

M A G N E T I C M A T E R I A L S

New Ferrite Material

Improves Split-Core Current

Transformers for Power

MeasurementA few years ago, engineers designing for the 50/60 Hz domain were dreaming about

“magic” materials for magnetic cores, which would provide the best performance at thebest price. Unfortunately the available technologies offered either a good performance

for a high price or much poorer performance for a low price.

By Pierre Turpin, Energy & Automation Project Manager, LEM

Figures 1: Ip = 20% of rated current, F = 50Hz, Core: FeSi, Air Gap = 25mm (one leg)Results: 5% transfer ratio error, 20° phaseshift

Figures 2: Ip = 20% of rated current, F = 50Hz, Core: FeNi-80%, Air Gap = 25mm (oneleg) Results: 0.15% transfer ratio error, 3.8°phase shift

Figures 3: Ip = 20% of rated current, F = 50Hz, Core: Ferrite, Air Gap = 5mm (one leg)Results: 0.004% transfer ratio error, 1.9°phase shift

The phase shift for the ferrite is half that of the FeNi core, so FeNi is

definitely out of the competition. The reduced air gap of the ferrite

core also allows a better accuracy of transfer ratio (primary turns to

secondary turns)

Let us look at some areas of application where the new ferrite core

material brings strong benefits.

Saving energy, for both cost savings and environmental considera-

tions, is a growing issue in many countries, but the key question is –

how can a substantial and sustainable reduction of energy consump-

tion be achieved? The most credible solution is to establish an under-

standing of how users consume their energy and make them respon-

sible for it. Targeting this area remains an industrial concern but is

also increasingly gaining importance for the public sector. Many

countries are supporting this by introducing campaigns and incentive

budgets for reducing energy consumption. Sub-metering is an

extremely powerful tool and LEM has introduced the TT series of cur-

rent transformers, which use the new ferrite material. These split-core

current transformers dramatically improve the cost/performance ratio

of electrical sub-metering solutions, especially for existing buildings.

The TT series is also an ideal solution for many other applications

that require accurate active power measurement, especially thanks to

the particularly low phase shift between measured voltage and cur-

rent and the high linearity, even at low current levels.

Contactless split-core current transformers can simply be snapped

over a cable, without the need to screw or weld on complex brackets,

making installation and maintenance straightforward. Furthermore

they can be installed in electrical control panels – thus avoiding com-

plex wiring – to remotely monitor devices that often operate in harsh

environments. In particular, since they are so easy to fit and put into

operation, the new small, safe, self-powered, split core current trans-

formers can be retro-fitted into existing installations without shutting

down operation, even in environments with limited space.

Principal applications for current transformers based on the new fer-

rite material will be in the fields of energy sub-metering and cost allo-

cation, dynamic consumption and peak analysis, energy waste or

defective equipment detection and power quality control.

www.lem.com

www.bodospower.com

M A G N E T I C M A T E R I A L S

Figure 4: A TT transformer

More than just Power

Tyco Electronics is releasing a sixpack – flow90PACK 1 –and a rectifier configuration – flow90CON 1 – in the 90° housing. The flow90CON is compatible with theflow90PACK in power range and pinning. They are bothavailable in 600V and 1200V. Both families support designswith 90° mounting angle between heat sink and PCB.These modules are dedicated to motor and servo driveinverters, which require the heat sink to be in an uprightposition (at 90° mounting angle) with respect to the PCB.

flow90PACK 1

flow90CON 1Main features:W Support designs with

90° mounting angle between heat sink and PCB

W IGBT technology for low saturation losses

W Clip-in PCB mounting

Power range: W flow90PACK 1:

up to 75A at 600V and up to 35A at 1200V

W flow90CON 1: up to 75A at 1600V

W Input rectifier optionally half controlled

Tyco Electronics Power Systems Finsinger Feld 1 85521 Ottobrunn, Germany Tel.: +49 (0)89 6089 830 Fax: +49 (0)89 6089 833 em.customerservice@tycoelectronics.comwww.em.tycoelectronics.com

Maxwell Technologies has introduced a

rugged 390-volt BOOSTCAP® ultracapaci-

tor module to provide scalable, easy-to-inte-

grate, energy storage and power delivery

solutions for heavy hybrid and electric vehi-

cles and heavy duty industrial applications

requiring up to 1,170 volts.

The new Heavy Duty Transportation (HTM)

module delivers industry-leading perform-

ance and reliability and long operational life

for vehicles and industrial systems that use

electrical energy to enhance their efficiency

and environmental compatibility. The newest

addition to Maxwell’s HTM product family

features enhanced integration technology

and up to 2.8 times greater energy storage

than earlier products.

“Ultracapacitor-based

solutions increase the

efficiency of systems

that consume electri-

cal energy, which

saves fuel or grid

power, thereby reduc-

ing emissions of

greenhouse gases

and other pollutants

associated with con-

ventional internal

combustion vehicles and energy generation,”

said Dr. Richard Balanson, Maxwell’s presi-

dent and chief executive officer. “This

rugged, high-performance, module is

designed specifically to meet the demanding

requirements of regenerative braking sys-

tems in hybrid and electric buses, trucks,

electric rail and other heavy vehicles, as well

as cranes and other heavy-duty industrial

applications.”

The new module meets or exceeds trans-

portation industry requirements for watt-

hours of energy storage and watts of power

delivery per kilogram, and is designed to

perform reliably through one million or more

deep discharge cycles, or about 15 years of

operational life for most vehicles or industrial

systems. Integrated voltage management

circuitry and monitoring capabilities and

highly efficient, fan-driven, forced air cooling

results in good thermal performance at high

continuous currents.

“In addition to efficiently managing thermal

loads under high current cycling conditions,

this module is built to withstand the harsh

environments, shock, vibration and extreme-

ly demanding duty cycles that are typical

with heavy transportation applications,” said

Michael Everett, Maxwell’s vice president

and chief technical officer. “Improvements in

module design and advancing cell perform-

ance through material science are enabling

enhanced functionality and robustness while

significantly reducing manufacturing cost.”

The self-cooled HTM BMOD0018-P390 is

encased in a rugged, splash- and dust-proof,

IP 65-compliant, aluminium chassis. Each

module is rated at 18 farads, and up to three

modules may be linked in series to deliver a

total of up to 1,170 volts. Maxwell also

offers standard 16-, 48- and 125-volt mod-

ules, and a “Quick-Turn” program that offers

shipment within 14 days of receipt of a cus-

tomer purchase order for custom-configured

modules for applications requiring up to 540

volts. Complete information and data sheets

for Maxwell’s module products is available at

the company’s website:

http://www.maxwell.com/ultracapacitors/inde

x.asp

BOOSTCAP ultracapacitors deliver up to 10

times the power and longevity of batteries,

require no maintenance and operate reliably

in extreme temperatures. In transportation

applications, they efficiently recapture ener-

gy from braking for reuse in hybrid and all-

electric drive trains, reducing energy con-

sumption and emissions. They also provide

compact, lightweight, “life-of-the vehicle”

solutions to stabilize automotive power net-

works and power new, all-electric subsys-

tems, such as drive-by-wire steering. In mis-

sion critical industrial applications, where

backup power is critical for continued opera-

tion or a soft shutdown in the event of power

interruptions, they provide reliable, cost-

effective, maintenance-free energy storage.

In wind turbine blade pitch and braking sys-

tems and other industrial applications, they

provide a simple, solid

state, highly reliable, solu-

tion to buffer short-term

mismatches between the

power available and the

power required.

Maxwell is a leading

developer and manufac-

turer of innovative, cost-

effective energy storage

and power delivery solu-

tions. Our BOOSTCAP®

ultracapacitor cells and

multi-cell modules provide safe and reliable

power solutions for applications in consumer

and industrial electronics, transportation and

telecommunications. Our CONDIS® high-

voltage grading and coupling capacitors help

to ensure the safety and reliability of electric

utility infrastructure and other applications

involving transport, distribution and measure-

ment of high-voltage electrical energy. Our

radiation-mitigated microelectronic products

include power modules, memory modules

and single board computers that incorporate

powerful commercial silicon for superior per-

formance and high reliability in aerospace

applications.

www.maxwell.com

P R O D U C T O F T H E Q U A R T E R

30 www.bodospower.comBodo´s Power Systems - April 2007

Heavy – Duty

Ultracapacitor ModuleIntegrated BOOSTCAP® Unit Provides Scalable Solutions for Energy-Efficient,

Environmentally Compatible Hybrid and Electric Buses, Trucks, Electric Rail Vehiclesand Industrial Systems

wwwsmt-exhibition.com

Mesago Messe Frankfurt GmbH, Rotebuehlstr. 83-85, 70178 Stuttgartsmt@mesago.de, phone +49 711 61946-74

Free entry ticket and further information here

www.smt-exhibition.com

Two of the most common transformer based DC-DC converter

topologies are the Flyback and Forward. These topologies are very

effective for high input to output step-down ratios since the trans-

former turns ratio can be set to accomplish the majority of the step-

down conversion.

For example, the conversion equation for a Forward converter is

approximately:

VOUT = VIN x D x Ns/Np

Where D is the duty cycle of the modulating switch, and Ns and Np

are the quantities of the transformer secondary and primary turns.

For VIN = 66V and VOUT = 3.3 (20:1 step down) the transformer

turns ratio (Ns/Np) can be set to 1:10, requiring the modulation

switch duty cycle to be 50%.

For a 500 kHz operation, the 50% duty cycle equates to a switch on-

time of 1 µs. For applications that do not require ground isolation, a

Buck regulator is a more desirable topology. The Buck topology pro-

vides a lower cost solution since it does not require a transformer.

The conversion equation for a Buck regulator is simply: VOUT = VIN

x D

Buck regulator applications with a high input to output step-down

ratio require a small duty cycle. Coupled with high-frequency opera-

tion, the on-time for the modulating switch becomes very small. The

high frequency and high step down ratio imposes significant chal-

lenges for the pulse-width modulation (PWM) controller. A buck regu-

lator with VIN = 66V and VOUT = 3.3V operating at 500 kHz will

require an on-time of 100 ns.

Common modulation control methods often used in buck regulators

include Voltage Mode (VM), Current Mode (CM), and Constant On-

Time (COT) control. Current-mode control provides ease of loop

compensation and inherent line feed-forward compensation, which

make this method a favourite among power designers. Voltage-mode

control is typically less noise sensitive but under-performs current

mode in transient response and ease of stabilization.

Constant On-Time control eliminates most of the stability-related

issues and responds well to line and load transients. However, COT

controlled regulators do not operate at constant switching frequency

and cannot be synchronized to an external clock.

Figure 1 shows the block diagram of a buck regulator utilizing the

current-mode control method. The output voltage is monitored and

compared to a reference, with the resulting error signal applied to the

PWM. The origin of the modulating ramp is where voltage mode and

current mode control differ. The modulating ramp used in current

mode control is a signal proportional to the buck switch current. The

inductor current flows through the buck switch during the switch on-

time. During this time, the inductor current waveform has a positive

slope of (VIN – VOUT)/ L.

An accurate, fast measurement of the buck switch current is neces-

sary to create the modulating ramp signal. The main disadvantage of

current-mode control is the difficulties encountered creating the buck

switch current signal.

Propagation delays and noise susceptibility make it almost impossi-

ble to use conventional current-mode control for high input voltage,

large step-down buck regulator applications where very small on-

times are required. Measuring the buck switch current is challenging.

The measurement techniques commonly used are; make a voltage

measurement across a shunt resistor or the buck switch ‘on’ resist-

ance or use a current mirror circuit coupled to the buck switch.

Each method requires a level shift to transpose the measured signal

down to the ground reference for application to the PWM comparator.

Even with the best design practices, current sense and level shift cir-

cuits will add a significant propagation delay.

P O W E R M A N A G E M E N T

32 www.bodospower.comBodo´s Power Systems - April 2007

Overcoming Challenges

in Design

Step-Down Regulator Applications with ≥ 40V Input Voltage

Switching regulators are commonly used to step-down a higher level, unregulated inputvoltage to a regulated output voltage. In applications requiring DC-DC conversion from arelatively high input voltage, a switching regulator will dramatically improve conversion

efficiency relative to linear regulator alternatives.

By Robert Bell, Applications Engineer National Semiconductor

Figure 1: Buck regulator using current mode control

Fuji Electric Device Technology Europe GmbHGoethering 58 · 63067 Offenbach am Main · GermanyFon +49 (0)69 - 66 90 29 0 · Fax +49 (0)69 - 66 90 29 56semi-info@fujielectric.de

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TMD Modules

Another challenge is, when the buck switch is turned on, the free-

wheel diode (D1) will turn off. A reverse recovery current will flow

through the diode and the buck switch, causing a leading edge cur-

rent spike and an extended ringing period. This spike can cause the

PWM comparator to prematurely trip, causing erratic operation.

The most common solution is to add filtering or leading edge blank-

ing to the current sense signal. Attempts to filter or blank this leading-

edge spike increase the minimum controllable on-time of the buck

switch.

Creating an Emulated Current Sense Signal

The challenge of accurate and fast buck switch current measurement

can be avoided with a new method that emulates the buck switch

current without actually measuring the current. In a buck regulator,

the inductor current is the sum of the buck switch current and free-

wheel diode current, as shown in Figure 2. The buck switch current

waveform can be broken down into two parts, a base or pedestal and

a ramp.

The pedestal represents the minimum inductor current value (or val-

ley) over the switching cycle. The inductor current is at its minimum

the instant the free-wheel diode turns off, as the buck switch turns

on. The buck switch and the diode have the same minimum current

value, occurring at the valley of the inductor current. A sample-and-

hold measurement of the free-wheel diode current, sampled just prior

to the turn-on of the buck switch can be used to capture the pedestal

level information.

The other part of the buck switch current waveform is the ramp por-

tion of the signal. The voltage across the inductor is the difference

between the input (VIN) and output (VOUT) voltages when the buck

switch is on. This voltage forces a positively ramping current through

the inductor and the buck switch. The ramping current slope is equal

to: di/dt = (VIN – VOUT) / L. An equivalent signal can be created with

a voltage controlled current source and a capacitor. The rising volt-

age slope of a capacitor (CRAMP) driven by a current source

(IRAMP) is equal to: dv/dt = IRAMP / CRAMP. If the current source is

set proportional to the difference between the input and output volt-

ages the capacitor ramp slope is equal to: dv/dt = K x (VIN – VOUT) /

CRAMP, where K is a scale factor for the current source and CRAMP

is the ramp capacitor.

The value of CRAMP can be selected to set the capacitor voltage

slope proportional to the inductor current slope.

Figure 3 presents the block diagram of the LM25576, one of six new

integrated buck regulators that implement the emulated current mode

control scheme described above. The top portion of the diagram

shows the normal buck regulator power switching components. The

free-wheel diode anode is connected to ground through the con-

troller.

A small value current sense resistor and amplifier are used to meas-

ure the diode current. The sample-and-hold circuit triggers each

cycle, just prior to the turn-on of the buck switch, providing the

pedestal portion of the emulated current sense signal.

The LM25576 senses the input voltage and the output voltage to

generate a current source that charges an external ramp capacitor

(CRAMP). Each cycle when the buck switch is turned on, the capaci-

tor voltage rises linearly. When the buck switch is turned off, the

ramp capacitor is discharged. For proper operation, the ramp capaci-

tor is set proportional to the value of the output inductor.

A good starting point is to select CRAMP = L x 10-5, where the units

of L are Henrys and CRAMP are Farads. The last step necessary to

complete the generation of the emulated buck switch current signal is

to sum the pedestal information (from the sample and hold) to the

ramp capacitor voltage signal. The final result is a controller that

behaves like peak current mode control but without the delay and

transient effects in the current sensing signal.

For applications operating with duty cycles greater than 50 percent,

peak current mode controlled regulators are subject to sub-harmonic

oscillation. By adding an additional fixed slope voltage ramp signal

(slope compensation) to the current sense signal, this oscillation can

be avoided. Referring to the ramp generator circuit, an additional

fixed 25µA offset current provides additional fixed slope to the capac-

itor voltage ramp signal. For very high duty cycle applications the

25µA current source the ramp slope, preventing sub-harmonic oscil-

lation.

34 www.bodospower.comBodo´s Power Systems - April 2007

P O W E R M A N A G E M E N T

Figure 2: Buck regulator waveforms

Figure 3: Emulated current mode control ramp generator

Overload Protection

The LM25576 output overload protection is accomplished with a ded-

icated current limit comparator that limits the emulated peak current

on a cycle-by-cycle basis. The emulated current mode method pro-

vides the added benefit of capturing the inductor current information

prior to the buck switch turn-on. If the current pedestal exceeds the

current limit comparator threshold, the buck switch skips cycles

allowing the inductor current additional time to decay, preventing cur-

rent runaway.

Current-mode control offers many benefits. However, in buck regula-

tor applications requiring very short on-times the generation of the

modulating ramp is very difficult. Through the use of an emulated

ramp signal this challenge can be overcome. National has developed

a new family of integrated regulators using the emulated current

mode control technique. For more information, visit switcher.nation-

al.com

www.national.com

35www.bodospower.com

P O W E R M A N A G E M E N T

Figure 4: LM25576 Buck regulator schematic

Digital Power Conversion Platforms

ColdWatt Inc. has introduced its digital power conversion portfolio

aimed at helping IT managers and systems designers address the

increasing challenges of spiraling IT power requirements and rising

energy prices. ColdWatt is one of a few companies delivering effi-

ciency without sacrificing density. The company is currently shipping

high efficiency power conversion products intended to enable IT

equipment vendors to decrease growing operational expenditures

(OPEX) and total cost of ownership by decreasing overall power con-

sumption and increasing server and IT hardware density.

Over 50 percent of typical data center power consumption today is

used for power delivery, thus operational costs are starting to outstrip

the cost of equipment itself. ColdWatt has introduced its first prod-

ucts, the 650W power sub-system and the AC-DC 1U 1200W power

supply, to help address these challenges. These flexible digital power

conversion platforms allow quick-turn customization and generate 45

percent less heat, which results in 30 percent less overall server

power consumption helping boost customers’ bottom line.

Systems designers can realize power conversion efficiencies up to

91 percent, with emphasis on light load efficiencies greater than 82

percent, and industry leading densities at these power levels.

Innovative system-level features provide enhanced system reliability

including fault detection and predictive failure features.

ColdWatt uses proprietary magnetics technology to increase energy

storage and digital control to achieve higher efficiency and flexibility.

Thus, ColdWatt’s front-end power supplies are able to significantly

exceed the 70 percent efficiency level of commodity power supplies,

with power headroom to scale with processing density increases and

feature additions.

FET Plus Driver Multi-Chip Module

Fairchild Semiconductor introduces the FDMF8700, the first model in

a new suite of highly integrated “FET Plus Driver Multi-chip Modules”

for use in high-current synchronous buck applications supporting

Intel’s DrMOS Vcore DC-DC converter standard. The FDMF8700 is a

fully integrated power-stage solution offered in a space-saving 8 x

8mm micro-lead frame (MLP) package. By replacing a 12V driver IC

and three N-channel MOSFETs, the FDMF8700 saves 50 percent

board space compared to discrete component solutions. The layout

and size of the switches and driver die are optimized to enable high-

er-frequency operation and are intended for use in desktop and serv-

er VR11.x vCore conversion, high-current DC-DC point-of-load con-

verters and small form factor voltage regulator modules. The

FDMF8700 enables designers to maximize footprint power density,

reduce component part count/BOM cost and shorten time to market.

Unlike discrete solutions whose parasitic elements combined with

board layout significantly reduce system efficiency, the FDMF8700

module is designed to both thermally and electrically minimize para-

sitic effects and improve overall system efficiency. In operation, the

high-side MOSFET is optimized for fast switching while the low-side

device is optimized for low RDS(on). This arrangement ideally

accommodates the low-duty-cycle switching requirements needed to

convert the 12V bus to supply the processor core with 1.0V to 1.2V

at up to 30A. Fairchild’s MLP 8x8 power package extends the con-

cept of enhanced packaging for DC-DC converter applications. The

integrated FDMF8700 module provides an additional efficiency gain

of 1.5 to 2 percent for peak- and steady-power levels compared to

discrete solutions using D-Pak packaging.

www.fairchildsemi.com

www.coldwatt.com

A P E C I N N O V A T I O N S

36 www.bodospower.comBodo´s Power Systems - April 2007

Snap Shots of Product Innovation

at APEC Anaheim CA

Energy-efficient digital power conversion platforms

2007International Exhibition& Conference forPOWER ELECTRONICSINTELLIGENT MOTIONPOWER QUALITY22 – 24 May 2007Exhibition Centre Nuremberg

Power On!

Conference:

Lisette Hausser

Tel. +49 711 61946-85

E-Mail: hausser@mesago.de

Exhibition:

Linda Raidt

Tel. +49 711 61946-56

E-Mail: raidt@mesago.de

Organizer:

Mesago PCIM GmbH

Rotebühlstraße 83-85

D-70178 Stuttgart

MesagoPCIM

Bodo´s Power SysBodo´s Power Systems

Free Magazin Subscription at

www.bodospower.com

for qualified readers in Europe

38 www.bodospower.comBodo´s Power Systems - April 2007

Extended LDO Family

Micrel introduced the 4A MIC68400, the latest addition to its

MIC68000 family of LDOs designed specifically for powering FPGA,

CPLDs, DSPs and microcontrollers. The devices are aimed at appli-

cations such as broadband modems, routers, servers, storage net-

works, and wireless base stations. The device was showcased for

the first time at APEC, The Applied Power Electronics Conference

and Exposition.

“With the introduction of the MIC68400, Micrel has the industry’s

broadest portfolio of solutions featuring integrated sequencing, track-

ing and ramp control,” noted Ralf Muenster, Micrel’s director of mar-

keting for power products. “The MIC68400 technology is reflective of

the entire MIC68000 family; it offers a very flexible framework in

order to meet the complex power-up protocols many of today’s

advanced mission critical systems require for reliable operation.”

The MIC68400 supports various power-up and power-down protocols

such as sequencing, tracking, and ratiometric tracking that can be

implemented very easily with the use of few passive components.

Additionally, multiple MIC68400 and/or other devices within the

MIC68000 family can be daisy-chained together for a complete syn-

chronized system power-up and power-down. The IC operates from

a wide input range of 1.65V to 5.5V and supports an output voltage

as low as 0.5V with 2 percent accuracy. Integrated protection fea-

tures include thermal, current limit and reverse current protection.

The MIC68400 is offered in a tiny 16-lead 4mm x 4mm MLF package.

Monolithic IC Targets 10W PSU Designs

Power Integrations has extended its DPA-Switch DC-DC IC family

with the introduction of the 10 W DPA422, which enables designers

to develop efficient power supply designs for Power Over Ethernet

(PoE) applications, and is especially suitable for Class 2 PoE imple-

mentations for applications such as VoIP telephones.

Explains Andy Smith, Power Integrations’ product marketing manager

for the DPA-Switch family: “Integrated PoE solutions available on the

market are a costly answer to a simple requirement. In contrast, by

using our DPA-Switch family plus a few low-cost discrete compo-

nents, designers can achieve a similar solution – simply, reliably and

cost-effectively.”

Power Integrations’ DPA-Switch family is the only scaleable family of

parts available that covers all current and proposed PoE classes from

3 W to 30 W and beyond. Rated at up to 10 watts output power, the

new DPA422 has been specifically designed to meet the power

requirements of IEEE802.3af Class 2 Powered Devices (PDs).

DPA-Switch family devices include a monolithic 220 V MOSFET and

feature voltage mode feedback control which requires no slope com-

pensation, an internal, tight tolerance cycle-by-cycle current limit

which needs no external current sense components and output over-

load and loop fault ‘auto-restart’ protection. Other benefits include

remote ON/OFF control, low EMI, high efficiency, soft start and hys-

teretic thermal shutdown. The DPA422 device is available in the DIP-

8 and SMD 8 package.

www.powerint.comwww.micrel.com

A P E C I N N O V A T I O N S

39www.bodospower.com Bodo´s Power Systems - April 2007

A P E C I N N O V A T I O N S

PolySwitch Protects Electric Motors and Transformers

Raychem Circuit Protection, a business unit of Tyco Electronics, has

announced the introduction of its PolySwitch™ LVR series of reset-

table circuit protection devices. PolySwitch LVR devices help protect

electric motors and transformers used in commercial and home

appliances from failures caused by mechanical overloads, overheat-

ing, stall, lost neutral and other potentially damaging conditions.

The PolySwitch LVR series includes components that are rated for

line voltages of 120 VAC and 240 VAC, for up to 2A of operating cur-

rent at 20°C. They offer low resistance, fast time-to-trip, a low pro-

file, and resettable functionality to help circuit designers provide a

safe and dependable product, comply with regulatory agency

requirements, and reduce warranty repair costs.

Unlike single-use fuses, PolySwitch devices do not require replace-

ment after a fault event. After the overcurrent condition is eliminated

and power has been removed, the circuit is restored to normal oper-

ating condition. Compared to bimetal breakers, they offer greater

flexibility, longer lifespan, and lower electromagnetic interference

(EMI).

The PolySwitch LVR devices’ resettable functionality and latching

attributes make them a reliable, cost-effective circuit protection solu-

tion for both intermittent and continuous-operation motor applica-

tions.

PolySwitch LVR devices also help prevent damage where faults may

cause a rise in temperature with only a slight increase in current

draw. When installed on the primary side of a transformer circuit, in

proximity to heat-generating components such as magnetics, field-

effect transistors (FETs), or power resistors, the PolySwitch LVR

device helps provide both overcurrent and overtemperature protec-

tion with a single installed component.

www.circuitprotection.com

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The On-line reference tool for the electronic industry

High-Power PoE Manager for Multi-Port Systems

Texas Instruments introduced the industry’s first fully integrated

Power over Ethernet (PoE) management device that allows multi-port

enterprise systems to deliver up to 25 watts of power over a standard

Ethernet cable. Supporting operation at -40º to +125º C, the power

source equipment (PSE) manager enables commercial, industrial,

medical and military applications to manage Ethernet-powered

devices using nearly twice the power as previous IEEE 802.3af-com-

pliant systems. See: www.ti.com/sc06238.

TI’s TPS23841 quad-port PoE integrated circuit (IC) provides power

management control and protection, while safely delivering up to 665

mA per port from input voltage levels of 21.5 V to 57 V. The device’s

extremely wide input voltage capability allows designers to support

emerging Ethernet-powered 24-V medical and industrial applications,

such as nurse call center systems and human machine-interaction

equipment.

The TPS23841 simplifies PoE design by integrating several key com-

ponents onto a single chip, including integrated switches and sense

resistors and four individual 15-bit analog-to-digital (A/D) converters,

which allows the device to accurately measure signature resistance,

voltage, current and die temperature. The device also can be

designed together with TI’s TPS2384 power source equipment man-

ager to enable high power and standard PoE operation in a system

running on the same comprehensive software. The TPS23841 also

provides three different options – automatic mode, semi-auto mode

or manual operation – that give designers added flexibility to meet

specific PoE system requirements. While in manual mode, the

TPS23841 can work with a microcontroller, such as TI’s MSP430

ultra-low-power microcontroller, to detect legacy capacitance loads.

High Current Cube Inductor

Providing design engineers with a robust, high frequency inductive

device, TT electronics BI Technologies Magnetic Components

Division has developed a high current cube inductor. Designated the

HM56 Series, the inductor’s low-loss, composite ferrite material has

characteristics suitable for high frequency applications.

“The HM56 Series inductor is a robust device that features a thick

coil, rated saturation current up to 60A, and is capable of operating at

frequencies up to 1MHz,” said David Smolik, Director of Product

Development for BI Technologies Magnetic Components Division.

“The design of this composite ferrite inductor makes it ideal for high

frequency and industrial applications.”

The HM56 Series high current cube inductor features inductance val-

ues from 0.22?H to 2.00?H, with DCRs from 0.60m? to 2.05m?.

Operating temperature range is -40°C to +125°C. BI Technologies

will also produce devices outside these specifications to meet cus-

tomer requirements.

The HM56 inductors are available in standard tray packaging.

www.bitechnologies.com

http://power.ti.com/poe

40 www.bodospower.comBodo´s Power Systems - April 2007

A P E C I N N O V A T I O N S

Intersil Corporation showcased its newest technology across its

broad power management portfolio.

The ISL8601 is a PMBus-compliant, single-phase PWM controller

with integrated MOSFET drivers that utilizes analog voltage mode

control and can be operated directly off a 12V power supply. The

PMBus digital interface allows power supply designers to configure,

control and monitor their power supplies through software, eliminating

the need for hardware changes and allowing extensive measurement

and reporting of power supply operating parameters without any

external components. Analog voltage mode control assures well-

known and easily-modeled loop dynamics and transient response

without the complexity and uncertainty that would be present in a dig-

ital control loop system. For more information, visit http://www.inter-

sil.com/cda/deviceinfo/0,1477,ISL8601,0.html.

ISL6260C is multi-phase controller that supports up to three phases

and is designed to meet Intel’s newest platform, code-named Santa

Rosa. The ISL6260C uses Intersil’s patented R3 Technology™

(Robust Ripple Regulator) to offer the best transient response and

load-line accuracy in its class. It has phase-dropping and phase-

adding capability to enhance efficiency across the entire load line.

For more information, visit http://www.intersil.com/cda/devicein-

fo/0,1477,ISL6260C,0.html.

ISL88731 is a highly integrated Li-Ion battery charger controller, pro-

grammable over the I2C system management bus (SMBUS). It throt-

tles the charge power, automatically limiting the current from the AC

adapter. The ISL88731 is intended to be used in a smart battery

charger (SBC) within a smart battery system (SBS). For more infor-

mation, visit

http://www.intersil.com/cda/deviceinfo/0,1477,ISL88731,0.html.

www.intersil.com

Power Management Portfolio

100V Current-Mode Buck Controller

National Semiconductor introduced the LM5116, the industry’s first

6V to 100V current-mode buck controller for use in telecommunica-

tions, automotive and industrial control applications. The LM5116

features a unique combination of high performance, flexibility and

ease-of-use for DC-DC power supply designs. The device joins

National’s portfolio of synchronous buck controllers, offering extend-

ed input voltage range and load current capability.

National demonstrated the LM5116 at the Applied Power Electronics

Conference and Expo (APEC) in Anaheim, California. The LM5116

is well-suited for step-down regulator applications from a high voltage

or widely varying input supply. The current mode control utilizing

National’s patented emulated current-mode (ECM) technology

reduces noise sensitivity of the pulse-width modulation (PWM) circuit.

It enables reliable control of very small duty cycles necessary in high

input voltage applications. Additional features include thermal shut-

down, programmable soft-start, frequency synchronization, cycle-by-

cycle current limit and adjustable line under voltage lockout (UVLO).

The emulated current ramp enables the LM5116 to exceed a 20:1

Vin:Vout step-down ratio when operating at 500 kHz. The operating

frequency is user-programmable up to 1 MHz with the capability to

synchronize switching to an external clock signal. A low quiescent-

current sleep mode disables the controller and consumes only 10

microamps of total input current for minimal off-state drain in battery-

powered applications. A user-selectable diode emulation mode

enables discontinuous inductor current operation at light load condi-

tions for improved efficiency.

www.national.com

41www.bodospower.com Bodo´s Power Systems - April 2007

A P E C I N N O V A T I O N S

For further info please contact us:E-mail: info@sanrex-europe.de

Web: www.sanrex.com

SanRex® Europee GmbH

Systems Design Motion and Conversion

Free Magazin Subscription at

www.bodospower.com

for qualified readers in Europe

Bodo s Power SystemsBodo s Power Systems

www.sensor-test.com

22. – 24.5.2007Nürnberg, Germany

Measurable better solutions foreven more precision, qualityand reliability

Mark your calendar now

www.sensor-test.com

Organiser:AMA Service GmbH · phone +49(0)5033.96390 · info@sensor-test.com

PoE is used in a multitude of applications

from Voice over Internet Protocol (VoIP)

telephony to wireless access points and

security cameras. Delivering power over

CAT-5 cable is no longer limited to enterprise

networks, but is gaining popularity for small

business and home office networks. With the

extension of PoE to a wider consumer base,

system designers are facing faster time-to-

market requirements while having to main-

tain product performance and standards

compliance.

The LTC4263 provides the smallest footprint

and simplest design for implementing IEEE

802.3af compliant Power Sourcing

Equipment (PSE). Housed in a tiny 4mm x

3mm DFN package and integrating a high-

voltage MOSFET, the LTC4263 requires only

a few external components to provide a

complete single-port PSE solution that will

detect, classify and provide 48 Volts to a

Powered Devices (PDs) such as a VoIP

phone. Advanced detection and power mon-

itoring techniques prevent damage to legacy

data-only equipment, while still supplying

power to newer, Ethernet-powered devices.

Offering standard-compliant AC or DC meth-

ods to sense the removal of a PD and fea-

turing sophisticated onboard control algo-

rithms, the LTC4263 provides autonomous

operation through all modes of operation

without processor intervention. The most

unique feature of the LTC4263, however,

may be its ability to manage power alloca-

tion across a multi-port system.

Seamless Execution of Complex Tasks

The LTC4263 performs multiple functions

autonomously, as required by the IEEE

802.3af standard. These include detection of

a compliant PD, classification, power supply

load management, powering on the port with

current limit and circuit breaker functions,

and removal of power after the PD has been

disconnected. The LTC4263 uses a force-

current detection method in order to reduce

noise sensitivity and provide a more robust

detection algorithm. The IC checks for the

signature resistance by forcing two test cur-

rents on the port in sequence and measuring

the resulting voltages. It then subtracts and

divides the two V-I points to determine the

resistive slope while removing voltage offset

caused by any series diodes or current offset

caused by leakage at the port.

If detection is successful, the LTC4263 per-

forms classification, identifying which of the

three IEEE power levels is present and

stores the detected class internally for use

by the power management circuitry. The

LTC4263 proceeds to power the port, while

providing current limit and current monitoring

functions. Inrush current limiting ensures that

the PD is powered-up in a controlled manner

without causing transients on the input sup-

ply. If at any time the port is shorted or an

excessive load is applied, the LTC4263 limits

port current to avoid hazardous conditions. If

the port current limit is exceeded continuous-

ly for more the 62ms, the port is turned off

and the LTC4263 waits four seconds before

restarting detection.

The LTC4263 can be pin configured for

either Endpoint or Midspan operation to

ensure proper powering of a PD in the case

44 www.bodospower.comBodo´s Power Systems - April 2007

C O M M U N I C A T I O N P O W E R

Single Port PoE Controller

Simplifies PSE DesignPower over Ethernet (PoE) has been enjoying rapid growth in popularity.

PoE provides the user with numerous benefits including fast and convenient installation,reduced overall power consumption, fewer cable runs, lower installation costs and a

unified, worldwide power standard based on the IEEE 802.3af specification.

By Alison Smith, Product Marketing Manager, Mixed Signal Products, Linear Technology Corporation

Figure 1: Single – Port Fully Autonomous PSE

of two PSEs connected to a single PD.

Midspan operation extends the detection

backoff timing so as not to continually corrupt

the signature as seen by the endpoint PSE.

The LTC4263 also offers standard-compliant

AC- or DC- disconnect methods to sense the

removal of a PD and turn off 48V power.

Easy Power Management in

Multi-Port Systems

Multi-port systems rely on a micro-

controller to arbitrate total power

supply load. The LTC4263 pres-

ents a novel way to achieve proper

allocation of power by using pro-

grammable onboard power man-

agement circuitry. The PWRMGT

pins of the LTC4263 are tied

together, along with an RC net-

work. When a new PD is added,

the LTC4263 immediately classi-

fies it and checks the voltage at

the shared PWRMGT node. If the

voltage at the node is less than 1V,

the power requirements of the new

PD can be met and the LTC4263

proceeds to power the port. If over

1V, the current is removed from

the node, port powering is aborted,

and the LTC4263 goes back into

detection mode. Thus no micro-

controller is needed to manage

total power supply loading, yet the

LTC4263 successfully manages proper

power allocation and provides maximum uti-

lization of the 48V power supply.

New Frontiers for PoE

Power over Ethernet has fundamentally

changed the way voice-over-IP telephones

and wireless access points are powered,

and it is spawning new breeds of Powered

Devices in the home, office, and industrial

settings. What the future holds for PoE is

unknown and it remains to be seen how

much of traditional electrical power will be

replaced by the efficient and clean advan-

tages of PoE. But next time your office

phone rings, check to see where that power

is coming from and start thinking of novel

and exciting applications for this new world-

wide power standard.

www.Linear.com

45www.bodospower.com Bodo´s Power Systems - April 2007

C O M M U N I C A T I O N P O W E R

Figure 2: Management in Multi-Port Systems

MiniPack 2 - IGBT Module with Converter Brake InverterAvailable in latest NPT andtrench IGBT technologies

Features• 10 - 30 A, 600 - 1200 V• Insulated base plate (DCB)• Pins suitable for wave soldering• High level of integration (NTC included)• Hiperfast free wheeling• Custom and standard configurations• Assembly clips available

Used in:• AC motor drives:

– Pumps, fans– Washing machines– Air-conditioning systems

• UPS

EUROPE:IXYS Semiconductors GmbHmarcom@ixys.de

USA:IXYS Corporationsales@ixys.com

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N E W P R O D U C T S

46 www.bodospower.comBodo´s Power Systems - April 2007

Rise time <0.6 µs solves problems of inflexi-

ble switches for testing Automotive-

Components

Quicker and simpler is now

the test of Automotive

Components with the new,

innovative Power amplifier

from Rohrer, Mess- und

Systemtechnik GmbH,

Munich. The new 4-

Quadrant HERO® POWER

amplifier Type PFL-1390

delivers an output voltage of

max. ±40 V und a continu-

ous current of max. ±60 A;

in short time up to ±80 A

(DC up to 800 kHz). With a

load of 60 A the voltage is

reaches in only 0.6 µs his

Maximum with zero voltage

overload. That’s why the

rise time <1µs can used

direct as an arbitrary func-

tion, with out going detour

on the switches edges. The change (<1µs)

of the test voltage is now possible to do

direct at the amplifier. It’s no longer neces-

sary to use a power switch and a second

voltage source. That means, all tests for

automotive components in which rise times

<1 µs can executed by direct controlling.

The previous less-than-ideal solution for

generate rise and fall times <1 µs with high

speed switches with switch from a fixed level

to another level is now history. All rise and

fall times up to 0.6 µs are now direct realize

under total load with arbitrary control. For

remote control the amplifier has a parallel

interface and can also be used for automatic

manufacturing and test. There are monitor-

ing sockets on the front panel for watching

voltage and current. The output has both a

short-circuit strength and an idle strength

and is proofed against over voltages. A

starter circuit will help to reduce the put on

current.

www.rohrer-muenchen.de

Highspeed Power Amplifier

LEM has introduced the LA 306-S, a panel-

mounted current transducer for the measure-

ment of currents up to 400 ARMS (@ +70°C)

or 300 ARMS (@ +85°C). The unit offers the

high performance of a closed-loop current

transducer at a very competitive price.

The new transducer is only 56mm high. It

features a wide maximum bandwidth of DC

to 50kHz and an overall accuracy of better

than 0.7 per cent at the primary nominal

RMS current. Typical linearity error is ±0.1

per cent at nominal current and the maxi-

mum offset temperature drift is 500

microamps from -40 to +85°C. The closed-

loop Hall-effect technology results in no

insertion losses and a fast response time of

less than 1 microsecond.

The transducer’s aperture accepts busbars

up to 13 x 30mm. Specified with 2000 turns

as standard, it is also available with 5000,

4000 or 3000 turns on request. A Molex

5045 plug is offered as standard for the sec-

ondary connections, to allow quick installa-

tion. A Molex series 70543 connector can be

specified for a more robust connection.

With an isolation test voltage of

6kVRMS/50Hz/1min, the transducer com-

plies with the EN50178 industrial standard.

All materials used satisfy UL94-V0. The LA

306-S is CE marked and is supplied with a

five-year warranty, as are all LEM industrial

products.

PCIM 2007– Hall 12.402

www.lem.com

Compact Current Transducer for 400ARMS

The AlCap design tool for scaling capacitor

banks for frequency converters has been

improved and extended. The library has

been extended with the new types of the

B43454, B43474 series with screw terminals

and the B43305, B43540 and B43508 series

with snap-in terminals having been listed in

the new data book (ordering number

EPC:27013-7600). At the same time, the

software has been updated with a full

reworking of the user interface, including

error messages, help functions and the cal-

culation procedure. Furthermore, the results

are now able to be saved as PDF files.

Version 4.0 of the ferrite tool has also been

reworked to allow calculation of user referred

parameters and to give access to the digital-

ized material data for all EPCOS ferrites and

their graphic displays. The database con-

tains all the materials covered by the 2007

Data Book. These include the materials N45,

T36 and T66 for broadband transformers, as

well as the materials N51 and N95 for power

transformers. The complex permeability and

impedance can now also be displayed as a

function of the frequency: the same applies

to the transferable power, with due consider-

ation of skin and proximity effects. In addi-

tion, the distortion (third harmonic) can now

be calculated under specific circuit condi-

tions at various temperatures.

With Ceramic capacitors, the latest innova-

tions mean the DC bias curves for various

ceramic materials are now available on the

internet. These allow the developer to deter-

mine how a capacitor’s capacitance changes

as a function of the applied DC voltage. TKC

curves have also been set up for various

capacitors, enabling capacitance change to

be determined as a function of temperature.

www.epcos.com

Design tool for easier Development

N E W P R O D U C T S

47www.bodospower.com Bodo´s Power Systems - April 2007

The new Dynaload RBL6000 Series, avail-

able exclusively in the UK from TTi (Thurlby

Thandar Instruments), is an electronic load

with a power level of 6 kW, making it ideal

for use in the fuel-cell, power-supply and

energy-storage markets that demand testing

at higher power

levels.

As well as setting

a new benchmark

for power, the

RBL 6000 also

sets new stan-

dards for program-

mability, speed,

frequency

response and

accuracy.

In the constant-

current or con-

stant-voltage

mode, the

Dynaload RBL

6000 is ideal for characterising the variations

in power output with hydrogen flow rate in

fuel cells. The pulse mode may be used to

determine the effects of

instantaneous current change, thus assisting

in establishing stability under real-world con-

ditions. With its high-speed response char-

acteristics, the unit may be used to deter-

mine the output impedance of the fuel cell.

The new 6 kW series of loads are available

in 100, 400 and 600 V ratings and are

offered with IEEE488, RS232 and Ethernet

communications. All RBL units are benchtop

or standard 19-inch rack mountable and can

be operated in parallel to achieve even high-

er power levels.

www.tti-test.com

Electronic Load for Testing Fuel Cells

Cree announced that it is shipping produc-

tion quantities of a new 50-amp Zero

Recovery Schottky rectifier operating at

1200 volts. The new CPW2-1200S050

demonstrates Cree’s ability to develop inno-

vative power-handling devices that can sig-

nificantly improve levels of efficiency in

power inverters. This advance means that

applications such as solar and wind power

converters, industrial motor drives, and elec-

tric vehicles using these Cree devices can

increase their operating efficiency beyond

current levels.

Compared with traditional silicon-based

diodes, Cree’s SiC-based Zero Recovery

rectifiers can:

Simplify Power Factor Correction Boost

design by eliminating the need for snubbers

and reducing component count.

Reduce power losses, leading to cooler

operating temperatures.

Produce significantly less electromagnetic

interference (EMI).

Better support new design objectives for effi-

ciency set forth by the EPA, California

Electric Commission and other agencies.

The CPW2-1200S050 reaches new power

levels because of significant SiC materials

quality advancements achieved in the last

year. It also features the industry’s largest-

area SiC die, with a die size of 8.2 mm x 4

mm. Fundamental to these advancements

are very low defect density substrates,

including zero micropipe SiC substrates.

This remarkable advance in technology was

made possible by pioneering research per-

formed by INTRINSIC Semiconductor,

acquired by Cree in 2006, in combination

with major research efforts funded by

DARPA and the Army Research

Laboratories.

www.cree.com

Silicon Carbide Schottky Rectifier

ROAL Electronics, a designer of ac-dc and

dc-dc switch-mode power supplies,

announced a new fully featured and efficien-

cy-optimized family of 50 W isolated, six-

teeenth-brick, dc-dc converters that are suit-

able for IT, Telecommunications and

Networking applications, and all other appli-

cations based on distributed power architec-

tures.

The new product family complements 48

Vdc bus applications for a distributed power

architecture concept using point-of-load dc-

dc modules. The converters offer a compact

board spacing

33.0x22.9x9.50mm(1.3x0.9x0.374in) and are

compatible with the industry-standard DOSA

specifications.

The new series operates from a 36 V to 75

V input bus voltage and delivers up to 25 A

with the1.2 & 1.8 V model,20 A with the 2.5V

model, 15 A with the 3.3 V model, 10 A with

the 5 V model, and 4.12 A from the 12 V

model, respectively.

The wide-trim, secondary-side control (-

50/+10% for the 1.8 V model; -42/+10% for

the 3.3 V model and -20/+10% for the 5 V

and 12 V models) makes the converters suit-

able for multiple and flexible applications,

and allows OEM companies to minimize

stock.

The series also features a fast transient

response, a back bias startup of 100% of the

set-point voltage, 1.5 kVdc of input-to-output

basic insulation.

www.roalelectronics.com

Sixteenth - Brick DC-DC Converters

N E W P R O D U C T S

48 www.bodospower.comBodo´s Power Systems - April 2007

ABB Entrelec 27

ABB semiconductors C3

AEPS Group 41

Ansoft 23

Correlec 39

CT Concept Technologie 9

Danfoss Silicon Power C2

Electrovac 21

Ferraz 35

Fuji Electric 33

Infineon 13

International Rectifier C4

Intersil 17

IXYS 45

LEM 3

Microsemi Power products 39

National Semi 4+6+15

PCIM Europe 37

Sanrex 41

Sensor + Test 43

SMT Nuremberg 31

Texas Instruments 11

Tyco Electronics 29

ADVERTISING INDEX

Allegro MicroSystems Europe has intro-

duced two new families of high-performance

low-noise Hall-effect current sensors featur-

ing an isolation voltage of 2100 V RMS.

Each device is available in ±5 A, ±20 A or

±30 A versions, with corresponding sensitivi-

ty levels of 185, 100 or 66 mV/A.

The new devices, ACS712 (bidirectional)

and ACS713 (unidi-

rectional), have

been developed to

address the growing

demand for low-

cost, high-accuracy

and compact cur-

rent-sensing solu-

tions with added

functionality. The

chip design is based

on the latest Allegro

low-noise 0.65 mm

BiCMOS process

(DABIC6), and

parameters such as

quiescent output

voltage, sensitivity and temperature coeffi-

cient have been optimised to minimise noise

and total output error.

The new current sensors provide lower noise

and higher accuracy than previous types,

and also include an integrated shield which

effectively attenuates high dV/dt voltage

transients across the leadframe - making this

solution ideal for motor control and high-side

current sensing applications.

The combination of improved process per-

formance, new design concepts and addi-

tional programming capability has resulted in

a twofold reduction in noise compared with

previous devices. The total output error is

only 1.5% at room temperature and +4% in

the industrial temperature range from -40º to

+85ºC.

www.allegromicro.com

Current Sensors with 2100 V RMS Isolation

Now available from TTI Europe is Kemet’s

new range of high capacitance, multilayer

ceramic capacitors (MLCCs), which includes

two new low profile

parts.

The new surface mount

X5R dielectric compo-

nents are housed in

0805 size cases and

have an overall height

of just 0.85mm (the

maximum allowable

height for EIA 0805

case size components

is 0.95mm).

Capacitance values

available are 4.7µF and

10.0µF, and both parts

have a voltage rating of

6.3VDC.

Low profile MLCCs are designed for use in

handheld and miniaturised electronics equip-

ment including LCD modules, mini-HDDs,

DSC, IC cards, Smart Cards, PMCIA cards

and MP3 players. Kemet X5R dielectric

MLCCs have low ESR and offer excellent

levels of reliability. They are suitable for

continuous use between –55 and

+85degC. The new parts are supplied in

tape and reel packaging suitable for

automatic pick and place assembly pro-

cedures. Both new devices meet the

requirements of RoHS legislation and

can be subjected to Pb-free solder pro-

files.

www.ttieurope.com

www.kemet.com

Multilayer Ceramic Capacitors

Survival of the fittest

... efficiency wins!

In the power conversion jungle ...

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IRF6645 SJ 100V 28mΩ 14nC 5.6nCIRF6665 SH 100V 53mΩ 8.7nC 3.4nC

Hall 12, Stand 202