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www.portabledesign.com August 2007 Featured Product: ARC VRaptor Video Subsystems WIRELESS COMMUNICATIONS: ZIGBEE NETWORKS CONSUMER ELECTRONICS: DIGITAL IMAGING PORTABLE POWER: POWERING BACKLIGHTS Design Ideas: Serving Multicell Apps & Thermal Management Embedded Software Embedded Software

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Editorial Director Warren Andrews, [email protected] Editor-in-Chief John Donovan, [email protected] Senior Editor Dave Cotton, [email protected] Managing Editor Marina Tringali, [email protected] Copy Editor Rochelle Cohn Associate Publisher Marina Tringali, [email protected] Product Marketing Aaron Foellmi, [email protected] Manager (acting) Advertising Sales Manager Michael Bognacki, [email protected]

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Page 1: Design Ideas: Serving Multicell Apps & Thermal

www.portabledesign.comAugust 2007

Featured Product:ARC VRaptor

Video Subsystems

WIRELESS COMMUNICATIONS: ZIGBEE NETWORKS

CONSUMER ELECTRONICS: DIGITAL IMAGING

PORTABLE POWER:POWERING BACKLIGHTS

Design Ideas: Serving Multicell Apps & Thermal Management

EmbeddedSoftware

EmbeddedSoftware

Page 3: Design Ideas: Serving Multicell Apps & Thermal

AUGUST 2007 �

contents departments editorialletter 6 dave’stwocents 8 industrynews 10 analysts’pages 14 productfeature 42 productsfordesigners 44 designidea 48

cover feature IntegratedStaticAnalyzers: 18 ANewBreed DavidN.Kleidermacher,GreenHillsSoftware,Inc.

TheMultimediaUserInterface: 22 ALookatThingstoCome NeilHendersonandGeoffKendall, MentorGraphicsCorporation

wireless communications Platform-IndependentSoftwareEnablesTrue 26 InteroperabilityinZigBeeNetworks SriniKrishnamurthy,AirbeeWireless,Inc.

consumer electronics WideDynamicRangeImagingTechniques �2 VenkataRaghavanS.,CypressSemiconductor

portable power PoweringBacklightsinPortableDevices �6 TomiKoskela,NationalSemiconductorFinland

100

90

80

70

60

50

40

30

20

10

0Design Code/UT Integration Beta Test Post Release

Phase

Uni

t of

Cos

t

SensorBoard

Analog orDigital

Interface

Sensors

ZigBeeNetworkModule

802.15.4 Radio+ MCU + ZigBeeNetworking Stack

DigitalInterface

WirelessInterface

ZigBeeSensor

Network

Radiocrafts

Sensorop

MaximumSignal

Photon Noise

NoiseFloor

NoiseSignal Photons Log Scale

10 100 1,000 10,000

Dark/Readnoise

18 embedded software

26 wireless telemetry

�2 image sensors

44 products for designers

Page 4: Design Ideas: Serving Multicell Apps & Thermal

4 PORTABLE DESIGN

teameditorial team

EditorialDirector Warren Andrews,[email protected]

Editor-in-Chief John Donovan,[email protected]

SeniorEditor Dave Cotton,[email protected]

ManagingEditor Marina Tringali,[email protected]

CopyEditor Rochelle Cohn

art and media team CreativeDirector Jason Van Dorn,[email protected]

ArtDirector Kirsten T. Wyatt,[email protected]

GraphicDesigner Christopher Saucier,[email protected]

DirectorofWebDevelopment Marke Hallowell,[email protected]

WebDeveloper Brian Hubbell,[email protected]

management team AssociatePublisher Marina Tringali,[email protected]

ProductMarketing Aaron Foellmi,[email protected] Manager(acting)

AdvertisingSalesManager Michael Bognacki,[email protected]

Circulation Shannon McNichols,[email protected]

executive management ChiefExecutiveOfficer John Reardon,[email protected]

VicePresident Cindy Hickson,[email protected]

VicePresidentofFinance Cindy Muir,[email protected]

DirectorofCorporateMarketing Aaron Foellmi,[email protected]

DirectorofArtandMedia Jason Van Dorn,[email protected]

portable design advisory councilMark Davidson,NationalSemiconductor

Doug Grant,AnalogDevices,Inc.

Dave Heacock,TexasInstruments

Kazuyoshi Yamada,NECAmerica

corporate officeTheRTCGroup

905CalleAmanecer,Suite250SanClemente,CA92673

Phone949.226.2000Fax949.226.2050www.rtcgroup.com

Forreprintscontact:MarinaTringali,[email protected].

PublishedbytheRTCGroup.Copyright2007,theRTCGroup.PrintedintheUnitedStates.Allrightsreserved.AllrelatedgraphicsaretrademarksoftheRTCGroup.Allotherbrandandproductnamesarethepropertyoftheirholders.PeriodicalspostageatSanClemente,CA92673.Postmaster:sendchangesofaddressto:PortableDesign,905CalleAmanecer,Suite250,SanClemente,CA92673.PortableDesign(ISSN1086-1300)ispublishedmonthlybyRTCGroup905CalleAmanecer,Suite250,SanClemente,CA92673.Telephone949-226-2000;949-226-2050;WebAddresswww.rtcgroup.com.

Untitled-4 1 2/7/07 2:57:41 PM

Page 5: Design Ideas: Serving Multicell Apps & Thermal

editorial team EditorialDirector Warren Andrews,[email protected]

Editor-in-Chief John Donovan,[email protected]

SeniorEditor Dave Cotton,[email protected]

ManagingEditor Marina Tringali,[email protected]

CopyEditor Rochelle Cohn

art and media team CreativeDirector Jason Van Dorn,[email protected]

ArtDirector Kirsten T. Wyatt,[email protected]

GraphicDesigner Christopher Saucier,[email protected]

DirectorofWebDevelopment Marke Hallowell,[email protected]

WebDeveloper Brian Hubbell,[email protected]

management team AssociatePublisher Marina Tringali,[email protected]

ProductMarketing Aaron Foellmi,[email protected] Manager(acting)

AdvertisingSalesManager Michael Bognacki,[email protected]

Circulation Shannon McNichols,[email protected]

executive management ChiefExecutiveOfficer John Reardon,[email protected]

VicePresident Cindy Hickson,[email protected]

VicePresidentofFinance Cindy Muir,[email protected]

DirectorofCorporateMarketing Aaron Foellmi,[email protected]

DirectorofArtandMedia Jason Van Dorn,[email protected]

portable design advisory councilMark Davidson,NationalSemiconductor

Doug Grant,AnalogDevices,Inc.

Dave Heacock,TexasInstruments

Kazuyoshi Yamada,NECAmerica

corporate officeTheRTCGroup

905CalleAmanecer,Suite250SanClemente,CA92673

Phone949.226.2000Fax949.226.2050www.rtcgroup.com

Intersil – Switching Regulators for precise power delivery.©2007 Intersil Americas Inc. All rights reserved. The following are trademarks or services marks owned by Intersil Corporation or one of its subsidiaries, and may be registered in the USA and/or other countries: Intersil (and design) and i (and design).

High Performance Analog

Intersil Battery Authentication

We’re On It.

Intersil’s ISL9206 FlexiHash+TM

Engine delivers high-security battery authentication at a low cost.Intersil’s ISL9206 is an easy-to-use, robust, and inexpensive battery authentication solution for 1-cell Li-Ion/Li-Polymer or 3-cell NiMH series battery packs.

Oscillator 1-Wire CommInterface

16x8 OTPROM

FlexiHash+Engine

POR/2.5VRegulator

ControlRegister

32-bitpseudo-randomchallenge word

from host

8-bitauthentication

code

32-bit HashFunction

64-bit Secret

32-bit HashFunction

FlexiHash+Engine

Patent pending FlexiHash+ engine consists of four separate programmable CRC calculators. Two sets of 32-bit secret codes are used for authentication code generation.

XSD single-wire host bus interface communicates with all 8250-compatible UARTs or a single GPIO pin. Supports CRC on read data and transfer bit-rate up to 23Kbps.

16 bytes of one-time programmable ROM memory for storage of pack information and ID, device authentication secrets, device default settings, and factory-programmed trim parameters.

Go to www.intersil.com for samples, datasheets and support

ISL9206 Key Features:Challenge/response-based authentication scheme using 32-bit challenge code and 8-bit authentication code.FlexiHash+ engine uses two sets of 32-bit secrets for authentication code generation.16x8 one-time programmable ROM memory.Additional programmable memory for storage.

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6 PORTABLE DESIGN

edit

oria

l let

ter

NNot long ago every start-up company dreamed of “going public.” You started off with private equity—mortgaging your house, borrowing from “angel investors” or venture capitalists—and, if you were lucky, you would end up go-ing public, achieving a valued stock ticker and access to a wide pool of equity financing. Tech IPOs were still popular in 2006; Infineon spun off Qimonda last August with a NYSE listing that brought in $546 million.

Now, suddenly, more and more publicly traded electronics and semiconductor compa-nies are dreaming of “going private” again. Right after the Qimonda listing, Philips spun off NXP to a consortium of private investors. Having lost its own bid for NXP, Freescale soon decided to go private itself, agreeing in December to be purchased by a consortium led by the Blackstone group for $17.6B.

Suddenly CEOs of publicly traded tech

companies—tired of being slaves to quarterly conference calls, Sarbanes-Oxley reporting requirements, proxy fights and the threat of shareholder lawsuits—started looking at going private. As of this writing, AMD, Micron, Lex-mark and Cadence are all rumored to be consid-ering going this route. Kohlberg Kravis Roberts (KKR) and the Blackstone Group—two of the largest private equity firms—are reportedly on the prowl for more tech company acquisitions. Is this the wave of the future? And is that good or bad for the electronics industry in general and the semiconductor industry in particular?

Companies have traditionally turned to the stock market to raise capital for expansion. They’ve then been able to use stock options to help retain staff. Silicon Valley firms in par-ticular used to give them out like candy, until the tech crash of 2001, and the more recent backdating scandal made options a lot less at-tractive than cash. The only alternative to the stock market used to be banks, but their role has been largely replaced by private equity firms, often fueled by hedge fund money. Pri-

vate equity firms raised an estimated $240B in the first half of 2007 in the U.S. alone, where their deals made up over a third of all mergers and acquisitions.

The arguments in favor of private equity are strong. Going private relieves executives of the need to constantly look over their shoulders at government regulators, shareholder lawyers, short sellers and irksome reporters who might cause their share prices to plunge. They now have only one boss with one agenda, not a spec-trum of bosses with conflicting agendas. Now if the company makes a profit, it can re-invest it in R&D without being hammered by investors to give it back to them. Strategic planning can now be focused on capital investments that will be of long-term benefit to the company, not worrying about the hit that will result in the next quarter.

The arguments against private equity are equally strong. Private equity firms are often accused of “asset stripping,” selling off parts of a company to turn a quick profit. In all fairness, this is often the case with any acquisition, sell-ing off loss-making parts of business to help re-store the company to profitability. Despite early fears, that hasn’t been the case with either NXP or Freescale, who began pruning such opera-tions as far back as 2000.

The larger problem is that private equity firms load up their acquisitions with more debt than any publicly traded firm would be allowed to accept. Paying down that debt load can cause serious problems in a notoriously cyclical indus-try like semiconductors. Freescale now carries a long-term debt of $9.4B, over 10x larger than before the LBO. They acknowledged in their March S-4 filing that their debt load from the merger may limit their ability “to obtain addi-tional funding,” something that was not a prob-lem when they had access to equity markets.

What will be the effect of private equity on the semiconductor market? NXP is a more prof-itable, nimble competitor since going private, as is Freescale. Both companies are moving to a “fab light” model and working with partners to cut the enormous CAPEX involved in mov-ing to smaller geometries. Both have laid off a large number of employees, though this is true in the case of most acquisitions. The overall effect of private equity would seem to be beneficial as long as the debt service remains tolerable.

Most private equity firms intend to re-list their acquisitions again in 3-5 years—the tra-ditional “exit strategy” of venture capitalists, which is what they are. We’re in the early stag-es of a 3-5 year experiment that will ultimately bring us back to where we started.

IsPrivateEquitytheWaveoftheFuture?

johndonovan,editor-in-chief

Page 7: Design Ideas: Serving Multicell Apps & Thermal

Intersil – An industry leader in Switching Regulators and Amplifiers.©2007 Intersil Americas Inc. All rights reserved. The following are trademarks or services marks owned by Intersil Corporation or one of its subsidiaries, and may be registered in the USA and/or other countries: Intersil (and design) and i (and design).

High Performance Analog

Intersil Handheld Products

Improve your performance in portable media players with Intersil’s high-performance analog ICs.

Power Management:Backlight DriversBattery AuthenticationBattery ChargersFuel GaugesIntegrated FET RegulatorsLCD Display PowerLDOsMemory Power ManagementOvervoltage and

Overcurrent ProtectionVoltage Monitors

Analog Mixed Signal:AmplifiersDCPsLight SensorsReal-Time ClocksRS-232 InterfaceSub Ohm Analog SwitchesSwitches/MUXesVideo DriversVoltage References

We’re Hip to Handheld.

Go to www.intersil.com for samples, datasheets and support

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8 PORTABLE DESIGN

dave

’s t

wo

cent

s

VVacations are a good time to watch people and how they use portable products. This year was the first time I noticed more women using cam-eras than men. Right after Mother’s Day I went to a major discount store to buy a package of plastic protection sheets for small LCD screens, but they were sold out. It would be another week before their camera accessories would be re-stocked after the recent camera buying frenzy. At the time, I thought a digital camera would be a nice gift, but may be seldom used.

Wow, was I wrong! My vacation observations showed that about three-fourths of the photogra-phers were female, often using more advanced Digital SLRs versus the simple point-and-shoot models. On the plane ride to our destination, a

woman sitting in front of me spent nearly a full three hours reading the user manual for her new DSLR. I wondered what my camera manual said that I didn’t know. While disembarking, I asked if she was ready to enjoy her new camera. She said yes, and was eager to experiment with the new modes of operation. Her husband spent his time reading newspapers.

Info Trends reported last year that digital camera sales would peak in 2006; predicted that 2007 and beyond will have flat or declining sales; and that several digital camera companies will have forgone the low-cost, point-and-shoot market. This may be due to the increasing num-ber of repeat buyers looking to upgrade their equipment. They represent more than 34 percent of a growing market. New camera technologies play a big role in repeat buying decisions. If the buyer moves into DSLRs, lenses could help to influence product loyalty. However, new tech-nology continues to be an important factor.

Recently several announcements were made concerning new technology for digital cameras. In particular, Kodak announced a new sensor

filter that can greatly improve low-light per-formance. It uses one monochromatic pixel for every color pixel. The traditional filter (Bayer pattern) uses two green, one blue and one red pixel to create RGB values. This innovation uses half the pixels to acquire luminance information and the other half for color information using the Bayer pattern ratio in order to process a color photo using Kodak-developed algorithms. This sensitivity improvement can be two to four times better than that obtained with the Bayer pattern filter. The benefits are faster shutter speeds for less motion blurring, much less noise at the same shutter speed and higher pixel count for the same size image. This innovation also has applications in cell phone cameras with small aperture lenses. Kodak plans to release the first cameras with this technology in 2008.

Improved low-light sensitivity can be cou-pled with image stabilization (IS), another valuable feature found on many new cameras. Initially, IS was found mostly on cameras with a 5X or better zoom. However, IS is also good for low-light and corresponding slow shutter speeds. Image stabilization enables either the lens to be stopped down by two to three F-stops or the shutter time to be four to six times longer. However, few hands can do better than 1/10 second, even with IS.

While visiting the Maine State Aquarium, I think I was the only male taking pictures out of the 10+ people with cameras. Many photog-raphers experienced frustration because either the flash bounced off the glass or the aquarium was too dark. But that did not stop the clicking shutters; it just resulted in more pictures being taken. Coupling IS with Kodak’s new filter and processing algorithm could improve light gath-ering by as much as 10X by using more light and longer shutter speeds, resulting in brighter photos without a flash. This convenience cer-tainly may motivate the repeat buyer—making many moms much happier.

For my two cents, photography used to be all about the lenses and the film. The recreational photographer would shoot a couple of rolls and hope that they had a few good pictures. Now, with digital photography, many more pictures are be-ing taken with the hopes for a higher ratio of good pictures. I think it will become increasingly im-portant to appeal to the recreational female pho-tographer who won’t want the camera to get in the way of a good memorable picture. For now, I think I’ll get my wife to read my camera’s owners manual and tell me what I don’t know.

DaveFreeman,TexasInstruments

dave’stwocentson...

WomenDrivingDigitalCameraFeaturesand

Technology

Page 9: Design Ideas: Serving Multicell Apps & Thermal

www.maxim-ic.com/MAX8647-info

1-800-332-86381-800-777-27761-888-MAXIM-IC

™DIRECT

FREE Displays Design Guide—Sent Within 24 Hours!CALL TOLL FREE 1-800-998-8800 (7:00 a.m.–5:00 p.m. PT) for a Design Guide or Free Sample

Distributed by Maxim Direct, Arrow, Avnet Electronics Marketing, Digi-Key, and Newark.The Maxim logo is a registered trademark of Maxim Integrated Products, Inc.

© 2007 Maxim Integrated Products, Inc. All rights reserved.

INDUSTRY’S FIRST NEGATIVEWHITE-LED CHARGE PUMPS ACHIEVE

HIGHEST EFFICIENCYIndependent Adaptive Mode Switching for Each LED Improves Efficiency by 12%

The MAX8647/MAX8648 utilize a negative charge-pump architecture to reduce in-line resistance and maximizeefficiency by delaying mode switching from 1x to 1.5x operation during battery discharge. Combined with independentadaptive mode switching for each LED, this architecture improves efficiency by 12%, even with high LED forward-voltage (VF) mismatching. These superior features make the MAX8647/MAX8648 ideal for cell phones, smartphones,portable media players, and other portable devices in which every milliamp-hour of battery life is crucial.

♦ Adaptive, Independent Current Regulator forEach LED

♦ Drive Up to Six White or RGB LEDs

♦ ±0.4% Accurate Current Matching

♦ Low 70μA IQ♦ 1MHz Fixed-Frequency Switching for Small

Components

♦ Multizone Light Management for Up to 32 BrightnessLevels or 32,768 Colors with RGB LEDs

♦ Ambient Temperature Derating Protects LEDs at HighTemperatures

♦ Serial Pulse Dimming Interface (MAX8648)

♦ EV Kit Available

♦ Prices Start at $1.95† (MAX8647) and $1.70†

(MAX8648)

†2.5k-up pricing provided is for design guidance and is FOB USA. International prices will differ due to local duties, taxes, and exchange rates. Not all packages are offered in 1kincrements, and some may require minimum order quantities.

MAX8647

LED6

LED5

NEGATIVECHARGEPUMP

1µF

Li+

IN

INTERFACECONTROL

SDA

NEG

SCL

VDD

I2CCONTROL

CURRENTREGULATORS

ANDSWITCHES

OUTPUT0.1mA TO 24mA

PER LED

1µF

LED2

LED1

LED3

LED4

93%PEAK EFFICIENCY

EACH LEDDYNAMICALLY SWITCHES

TO MINIMIZE LOSS

16-TQFN

3m m x 3 mm

INPUT2.7V TO 5.5V

DELIVERS 12%HIGHER EFFICIENCYTHAN COMPETITION

100

90

80

AVG81%

AVG69%

70

60

50

404.20 3.90 3.85 3.80 3.75 3.70 3.65 3.60 3.55 3.50 3.40 3.00

EFFICIENCY vs. Li+ BATTERY VOLTAGE(Four LEDs, IF = 15mA, VF1 = 3.7V, VF2 = 3.6V, VF3 = 3.5V, VF4 = 3.4V)

MORE BATTERY LIFE,NO ADDED COST

CONVENTIONAL POSITIVE CHARGE PUMP

MAX8647

Li+ BATTERY VOLTAGE (V, TIME WEIGHTED)

EFFI

CIEN

CY P

LED/ P

BATT

(%)

MAX8647_8 Portable Design US 8/14/07 9:39 AM Page 1

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10 PORTABLE DESIGN

news

Get Connected with companies mentioned in this article. www.portabledesign.com/getconnected

Get Connected with companies mentioned in this article. www.portabledesign.com/getconnected

Get Connected with companies and products featured in this section.www.portabledesign.com/getconnected

Ad Index

End of ArticleProducts

Get Connected with technology and companies providing solutions now

Get Connected is a new resource for further exploration into products, technologies and companies. Whether your goal

is to research the latest datasheet from a company, speak directly with an Application Engineer, or jump to a company's technical page, the goal of Get Connected is to put you in touch with the right resource. Whichever level of service you require for whatever type of technology, Get Connected will help you connect with the companies and products you are searching for. www.portabledesign.com/getconnected

Get Connected with companies and products featured in this section.www.portabledesign.com/getconnected

Get Connected with technology and companies providing solutions nowGet Connected is a new resource for further exploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, speak directly with an Application Engineer, or jump to a company's technical page, the goal of Get Connected is to put you in touch with the right resource. Whichever level of service you require for whatever type of technology, Get Connected will help you connect with the companies and products you are searching for.

www.portabledesign.com/getconnected

Microchip Launches Semiconductor Wiki

Microchip Technology Inc. has announced ICwiki (www.microchip.com/ICwiki)—a Web site that enables engineers, students and profes-sors working with microelectronics to collabo-rate and share information related to semicon-ductor products, applications and best practices. Using Wiki technology, participants can change content on the site and participate in Web log-

ging (or “blogging”), voting and messaging. IC-wiki is available in several different languages, including English, Spanish, Chinese, Japanese, French, German and Russian.

Following recent trends toward online so-cial networking, ICwiki was designed to help engineers share knowledge about designs and applications, and to help university students gain access to industry knowledge that can help bridge their transition from academia to industry. Participants can work together in ei-ther public or private blogs via the site’s Group Decision Support Systems (GDSS) feature. Subject areas include vertical markets such as automotive, home appliances and robotics; function topics such as algorithms, oscillators, PCB layout best practices and signal condition-ing; or product topics such as microcontrollers, Digital Signal Controllers (DSCs), analog and memory products.

ICwiki’s GDSS feature enables an author to start a new blog and invite selected mem-bers to join the group, while restricting access to others. In addition to blogging, ICwiki al-lows voting or “polling,” where users can post a question and then view the responses online.

Its “messaging” feature allows users to com-municate with each other, without disclosing e-mail addresses. MicrochipTechnologyInc.,Chandler,AZ.(480)792-7200.[www.microchip.com].

AMI Semiconductor Reports Earnings Up, Market Focus Shifting

In a conference call with editors and analysts, Dr. Ted Tewksbury, president and chief oper-ating officer of AMI Semiconductor (AMI), expanded on the recently announced financial results for Q207.

AMI (NASDAQ: AMIS) announced second quarter revenues of $157.0 million, an increase of 4% both sequentially and year on year. Gross margins were down slightly at 44.9%; operating margin was 6.1%, flat from Q1 but up slightly from Q206. GAAP operating mar-gin was 6.1%; non-GAAP was 14.0%, the dif-ference being due to acquisition and restructur-ing charges.According to an AMI statement, operational improvements that contributed to gross margins were “unfortunately offset by product mix.”

In Q2 07 AMI made 28% of its revenues ($45 million) from the automotive segment; 16% ($26 million) in the medical sector; 25% ($38 million) in industrial; 8% ($13 million)

in military/aerospace; and 7% ($12 million) in communications. Tewksbury attributed the hit on their operating margin to the medical sec-tor. Three factors were responsible: the FDA tightening qualification standards for medical devices; Medicare tightening reimbursements for medical imaging procedures; and inventory buildup among AMI’s medical customers. Still, Tewksbury expects the medical segment—where, according to Gartner, AMI is the num-ber one chip supplier—to be up year on year.

Tewksbury noted that AMI, which has long

Page 11: Design Ideas: Serving Multicell Apps & Thermal

AUGUST 2007 11

run its own foundries in Europe and the U.S., intended to focus more on value added services and less on fabrication. “We used to be primari-ly a foundry/ASIC company,” said Tewksbury; “We have now migrated to a more market fo-cused model rather than technology-based. We offer whatever skills and technologies custom-ers need to solve their problems.” Whereas pre-viously AMI’s primary differentiation had been process technologies, their new focus will be on adding more value. Process differentiation will be less critical. “Our foundry strategy will be: Use the lowest cost technology that will get the job done.”AMISemiconductor,Pocatello,ID.(208)233-4690.[www.amis.com].

Software Defined Radio May Play Key Role in Emerging Broadband Wireless Access Market

According to a new study commissioned by the SDR Forum, software defined radio (SDR) stands poised to play a major role in deliver-ing emerging triple-play services—voice, data/Web and video—to portable devices.

The 52-page study—titled “Wi-Fi, WiMAX, and Beyond 3G/4G” and subtitled “Broadband Wireless Access (BWA)”—provides a com-prehensive look at BWA market opportunities for the SDR community and the challenges it faces.

One such opportunity, the study says, is multiradio, whereby multiple radio standards (or waveforms) are included on a single mo-bile, portable or infrastructure platform. For example, a GSM cellular, a Wi-Fi and a GPS waveform could operate in parallel to provide wide-area, local-area and location services. As a result, SDR would need to address not only waveform selection—its traditional focus—but also simultaneous operations.

The SDR opportunities would be focused on reuse, portability, minimizing co-channel interference, optimizing RF links, beam-form-ing, multi-user detection, antenna sharing and power reduction.

The study concludes that virtually all stake-holders in the industry have indicated inten-tions for multiradio deployments that address Wi-Fi, WiMAX and beyond 3G waveforms on common platforms and for using SDR-centric

concepts and technologies to achieve the SDR platform benefits. SDRForum,Denver,CO.(303)628-5461.[www.sdrforum.org].

NFC Forum Issues Specifications for Four Tag Types

The NFC Forum, a non-profit industry asso-ciation that advances the use of near field com-munication (NFC) technology, has announced the publication of four tag type technical speci-fications. The specifications are available to the public for download at no charge from the NFC Forum Web site, www.nfc-forum.org/specs/.

NFC is a short-range, wireless connectivity technology that allows consumers to perform safe, contactless transactions, access digital content and connect electronic devices with the simplicity of a single touch. Consumers with NFC-enabled mobile phones may, for example, leave their wallets at home and use their phones to conduct contactless financial transactions, or to gain electronic access to public transporta-tion.

Tags are integrated circuits that store data that can be read by NFC-enabled devices to support these applications. For example, a cin-

ema goer with an NFC-enabled mobile phone may touch the phone to a movie poster contain-ing an embedded NFC tag to view a preview of the movie.

By standardizing the tag types and formats with the specifications announced today, the NFC Forum is promoting interoperability across the NFC market, enabling low-cost vol-ume production, and clearing a path to a glob-al, cost-effective mass market. More than one billion NFC-ready tags are already deployed worldwide for use in areas such as accessing public transportation, hotel rooms and offices.NFCForum,Wakefield,MA.(781)876-8955.[www.nfc-forum.org].

Accellera Announces Election of Corporate Member Companies to Its Board

Accellera, the electronics industry organi-zation focused on Electronic Design Automa-tion (EDA) standards, has announced that its Board of Directors elected fourteen Corporate Member companies to its Board for the 2007/8 membership year. The election was held at the Accellera Board meeting at the Design Auto-mation Conference.

Accellera Corporate Member companies for 2007/8 are: ARM Ltd., Cadence Design Sys-tems, Denali Software Inc., Freescale Semicon-ductor, IBM, Intel Corporation, Magma Design Automation, Mentor Graphics, Nokia, Novas, Rockwell Collins, Sun Microsystems, Synop-sys Inc. and Texas Instruments. The Accellera Board, comprised of these companies, includes representation from users and suppliers alike. Bringing additional industry perspective to Accellera standards are: Aldec, Inc., Archpro Design Automation, Azuro, Inc., Certess Inc., Jasper Design Automation, OneSpin Solutions, Silvaco, SpringSoft, Inc., ST Microelectronics, Toshiba and Xilinx, which are represented in Accellera as Associate Members.

Accellera has developed nine standards that have been transferred to the IEEE. Seven have been ratified by the IEEE and the two newest ones are in active IEEE working groups now. Accellera’s successes in advanced design and verification language standards include Sys-temVerilog and the Property Specification Lan-guage (PSL). Accellera recently completed the Unified Power Format (UPF) standard and is currently developing a Unified Coverage In-teroperability (UCI) standard.AccelleraOrganizationInc.,Napa,CA.(707)251-9977.[www.accellera.org].

Cirrus Logic Closes Transaction to Acquire Apex Microtechnology

Cirrus Logic Inc. has announced that it has closed on its agreement to acquire Apex Mi-crotechnology, a leading provider of precision high-power analog amplifier products, for ap-proximately $42 million in cash.

Founded in 1980 with headquarters in Tuc-son, Ariz., Apex Microtechnology is a leading innovator of integrated circuits, hybrids and

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12 PORTABLE DESIGN

news

modules used in a wide range of industrial and aerospace applications that require high-power precision analog products, such as PWM and power amplifiers. These precision amplifiers are used for driving motors, piezo electrics, programmable power supplies and other devic-es requiring high power and precision control.

Cirrus Logic intends to continue marketing the Apex hybrid products under the Apex pre-cision Power brand and supporting Apex’s ap-proximately 80 products and 1,200 customers worldwide.CirrusLogic,Austin,TX.(512)851-4000.[www.cirruslogic.com].

Wolfson Acquires Sonaptic Limited

Wolfson has announced that it has acquired Sonaptic Limited for an initial consideration of $24.8M. Wolfson extends its mixed-signal audio leadership with the acquisition of world class acoustic technology—enabling exciting new user experiences for consumer electronic devices.

Sonaptic Limited is a world leading pro-vider of advanced micro-acoustic technolo-gies based on more than 12 years of research by Sonaptic’s founders. The acquisition will provide the third part of Wolfson’s AudioPlus growth strategy, which is aimed at building on Wolfson’s world-class position in high fidelity audio semiconductors.

The acquisition will enable Wolfson to com-bine mixed-signal design and acoustic skills to offer advanced active noise cancellation, sound enhancement, 3D sound and acoustic echo cancellation in combination with its ex-isting high-quality, low-power audio products for consumer electronic applications. These in-clude Personal Media Players (PMP), mobile handsets, portable gaming consoles, Flat Panel TVs (FPTV), Portable Navigation Devices (PND) and automotive applications.WolfsonMicroelectronics,Inc.,SanDiego,CA.(858)6765090.[www.wolfsonmicro.com].

Ericsson and Texas Instruments to Co-Develop �G Solutions for Handset Manufacturers

Ericsson and Texas Instruments have an-nounced that the companies will form a strategic technology engagement to develop custom solu-tions for new Open OS-enabled 3G devices.

Solutions from the technology created by the two companies will combine 3G modems from Ericsson Mobile Platforms with OMAP applica-tions processors from TI. Solutions from the joint engagement will include OMAP, custom base-bands and connectivity technologies and will be capable of supporting the major Open OS, which offers easy access to a rich array of applications and services. The result of this joint effort will en-able all device manufacturers to offer advanced Open OS handsets for both the high-end and the rapidly growing mid-range market.

Ericsson’s access technology, current HSPA-enabled platforms and future HSPA evolution and LTE technologies, combined with the multimedia performance enabled by TI’s OMAP 2, OMAP 3

and future generations of OMAP processors, are intended to push the performance boundaries of mobile devices and mobile entertainment fea-tures. By leveraging TI’s OMAP platform with Open OS support for Windows Mobile, Symbian S60, Symbian UIQ and Linux, these solutions will provide OEMs and operators with a robust and flexible architecture for applications and services deployment. This will enable handset manufac-turers and mobile operators to differentiate their products through easy-to-use and customizable user interfaces, and through a robust and flexible application architecture.

Handsets based on these solutions are ex-pected to be available on the market in the sec-ond half of 2008. TexasInstrumentsInc.,Dallas,TX.(800)336-5236.[www.ti.com].

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Get Connected with technology and companies providing solutions nowGet Connected is a new resource for further exploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, speak directly with an Application Engineer, or jump to a company's technical page, the goal of Get Connected is to put you in touch with the right resource. Whichever level of service you require for whatever type of technology, Get Connected will help you connect with the companies and products you are searching for.

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14 PORTABLE DESIGN

analysts’ pages

New Influences Are Shaping User Expectations for Mobile Handsets

The global handset market could be about to undergo a major change during the next five years, providing handset vendors and compo-nent suppliers with opportunities to reshape consumers’ understanding of mobile devices, mobile computing and mobile connectivity, reports In-Stat. Four key factors that the high tech market research firm expects to shape handsets in the coming five years include the

Apple iPhone; alternative networks, such as Wi-Fi and WiMAX; mobile video and televi-sion; and more corporate-liable subscriptions.

“These influences will have a powerful ef-fect on the design of mobile devices, as well as the semiconductors and applications used in them,” says David Chamberlain, In-Stat ana-lyst.

Recent research by In-Stat found the follow-ing:

• The iPhone introduced a number of tech-nologies that were not yet common in mo-bile phones including touch screens and acceleration and proximity sensors.

• Both business and consumer users are ex-

pected to drive development of dual-mode cellular/Wi-Fi handsets.

• Deployment of mobile broadcast networks (e.g., DVB-H and MediaFLO), as well as other sources of video for mobile devices, will require changes to handset applica-tions, semiconductors and displays to pro-vide the best viewing experience.

• WiMAX could lead to a new generation of devices that combine cellular and Internet functions.

In-Stat,Scottsdale,AZ.(480)483-4440.[www.in-stat.com].

DRAM Disaster Sinks Suppliers in Q2

How bad were conditions in the DRAM market in the second quarter? According to iSuppli:

• So bad that global DRAM revenue declined by 24.1 percent, falling to $7.3 billion, down from $9.7 billion in the first quarter.

• So bad that Samsung Electronics Co. Ltd. and Micron Technology Inc., which suf-fered 16.7 percent and 15.7 percent respec-tive declines in revenue during the quarter, actually significantly outperformed the market and gained share.

• So bad that the DRAM per-megabit Aver-age Selling Price (ASP) plunge of 39 per-cent was actually marginally good news, because it was slightly less than the 40 per-cent drop iSuppli Corp. had predicted.

Indeed, it was a terrible quarter for DRAM

makers, with only one supplier among the Top-10, Etron Technology Inc., managing to grow its revenue during the period.

A major culprit behind the poor market condi-tions was a rise in part availability, with megabit shipments increasing by 23 percent during the period. This was nearly 3 points higher than the increase predicted by iSuppli, indicating that the market oversupply in the second quarter was even more severe than anticipated.

The second quarter’s 23 percent sequential megabit growth was even higher than the 21 per-cent rise in the first quarter. The DRAM bit growth in the first half of 2007 increased by 89 percent compared to the first half of 2006. This over-

PreliminaryDRAMRevenueMarketShareinQ2,2007(RevenueinMillionsofU.S.Dollars)Source: iSuppli Corp. July2007

table 1

Q2 Rank Company Q2 ‘07

Revenue

Q2 Share Q1 ‘07

Revenue

Sequential

Growth

Q2 ‘06

Revenue

Year to Year

Growth

1 Samsung 2,083.8 28.4% 2,503 -16.7% 2,150.0 -3%

2 Hynix 1,518.0 20.7% 2,160 -29.7% 1,174.0 29%

3 Qimonda 988.0 13.5% 1,283 -23.0% 1,206.0 -18%

4 Elpida 885.0 12.1% 1,171 -24.4% 764.0 16%

5 Micron 741.8 10.1% 880 -15.7% 854.0 -13%

6 Nanya 347.0 4.7% 510 -32.0% 534.0 -35%

7 Powerchip 318.0 4.3% 527 -39.7% 342.0 -7%

8 ProMos 224.0 3.1% 393 -43.0% 260.0 -14%

9 Etron 94.0 1.3% 85 10.6% 57.0 65%

10 Winbond 38.0 0.5% 45 -15.6% 36.0 6%

Others 96.3 1.3% 101.0 -4.7% 109.0 -12%

iSuppli

Total

7,333.8 100.0% 9,658 -24.1% 7,486.0 -2%

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Page 15: Design Ideas: Serving Multicell Apps & Thermal

AUGUST 2007 15

supplied market condition contributed greatly to the drop in prices in the second quarter.

While the DRAM companies encountered varying fortunes in the second quarter, there were no real losers and winners. The industry as a whole experienced painful price drops amid an extremely oversupplied situation. The market clearly hit the bottom in the second quarter, and the suppliers’ profitability will be much better in the second half of the year, iSuppli predicts.iSuppliCorporation,ElSegundo,CA.(310)524-4000.[www.isuppli.com].

Bluetooth Market Continues Growth, but Rate Is Slowing

Bluetooth had another successful year in 2006, and it will have continued success in 2007, led by its increasing penetration into mo-bile phones, reports In-Stat. However, market growth for Bluetooth products is beginning to slow, and it will see some complications arising from integration trends and new Bluetooth stan-dards hitting the market, the high-tech market research firm says. The market for Bluetooth chips is also in flux.

“The Bluetooth silicon market is beginning to see some consolidation, as larger silicon vendors add new capabilities, such as Wi-Fi and GPS, to their chip portfolios, either by in-ternal development or acquisition,” says Brian O’Rourke, In-Stat analyst. “The goal is to cre-ate combined radio silicon that is being de-manded by mobile phone vendors.”

Recent research by In-Stat found the following:• Growth of Bluetooth devices will increase by

34% in 2007, slowing from the recent past.• Wireless chip companies are seeking to of-

fer integrated radio chips with Bluetooth, Wi-Fi, GPS and FM.

• New low power and high data rate Blue-tooth standards will emerge over the next two years.

• According to recently conducted In-Stat surveys; France, Germany and the UK have the highest percentages of those extremely or very familiar with Bluetooth. Korea and Japan had the lowest percentages, while the U.S. was in the middle.

In-Stat,Scottsdale,AZ.(480)483-4440.[www.in-stat.com].

Smartphones Headed for Mass Adoption in China

Driven by the continuous functional improve-ment of Smartphones, the introduction of mid-dle-range models, better designs and the enrich-ment of third-party applications, 10.46 million Smartphones shipped in China in 2006, double from 2005, reports In-Stat. The explosive growth indicates that the Chinese Smartphone market will soon enter the mass adoption stage, the high-tech market research firm says. Entertain-ment functions are Chinese Smartphone owners’ primary favorites, rather than productivity func-tions, according to an In-Stat consumer survey.

“The most important three factors respon-dents would consider when purchasing their next Smartphone are function, brand and price,” says Raymond Yan, In-Stat analyst. “Security, Internet access and synchronization with PCs are the top three problems that existing Smart-phone users thought needed improvement.”

Recent research by In-Stat found the following:• 97.9% of Smartphone users would pur-

chase another Smartphone when their cur-rent phone needs replacement.

• More than half of Smartphone owners paid $25 or more every month for wireless ser-vices, 30% higher than that of non-Smart-phone users.

• Most Smartphone users have no idea about the OS of the phone and do not care about it when purchasing Smartphones.

In-Stat,Scottsdale,AZ.(480)483-4440.[www.in-stat.com].

Government Drives �G Wireless Transition in China

China’s National Development & Re-form Commission (NDRC) believes that a fundamental restructuring of the nation’s telecom industry is essential to promote the long-term growth of the country’s fixed and wireless core communications networks. Because of this, the Chinese government is offering 3G licenses to the four state-owned telcos—China Mobile, China Unicom, China Telecom and China Netcom—as incentives if they are willing to accept reforms, accord-ing to iSuppli Corp.

iSuppli believes that China’s core fixed and wireless networks all are transitioning to In-ternet Protocol (IP)-based Next-Generation Networks (NGNs). Furthermore, increasing numbers of media gateways and servers will allow China’s telecom networks to deploy advanced support services, video content distribution and online gaming. By offering this improved multimedia capacity, operators can more easily introduce new value-added services that in turn will generate more rev-enue for the state-operated companies. Mobile handsets in China also will have to incorpo-rate more advanced multimedia capabilities and open operating systems.

iSuppli forecasts that China’s TD-SCD-MA 3G subscribers will jump to 28 million by 2011, up from 1.1 million subscribers in 2007. By 2008, 3G subscribers in China will reach 6.4 million. For each of these subscrib-ers, a new mobile handset will be required,

2006 2007 2008 2009 2010 2011

25,000

20,000

15,000

10,000

5,000

0

Mill

ions

of U

.S. D

olla

rs

Others

Video

Music

Games

Pictures

Color Ring Back Tones

MMS

SMS

iSuppli Figure: China’s 3G Value-Added ServiceForecast (Millions of U.S. Dollars)

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16 PORTABLE DESIGN

analysts’ pages

offering a new selling opportunity for many companies inside the wireless telecom indus-try in China.

However, iSuppli believes that a key revenue driver in China will come from the applications that will be enabled by 3G. Chinese consum-ers will be able to access the Internet, down-load music, stream Internet video, use mobile mailboxes, pay bills online and engage in mo-bile blogging and interactive 3D gaming—all through their mobile phones.

This expansion of the value-added servic-es to the telecom industry in China will in-fuse the country with new revenues coming from domestic consumers. iSuppli believes most consumers will be naturally curious to explore the additional functions of their mobile handsets. iSuppli forecasts China’s 3G value-added services market will grow to $19.5 billion in revenue by 2011, main-taining a Compound Annual Growth Rate (CAGR) of 17.4 percent from $8.8 billion in 2006.

The table presents iSuppli’s revenue forecast for 3G value-added services in China for the period of 2006 through 2011.iSuppliCorporation,ElSegundo,CA.(310)524-4000.[www.isuppli.com].

Portable Devices Help Drive Rising Power-Management Chip Sales

The global power-management semiconduc-tor market will expand significantly during the next few years, driven in part by rising demand from makers of portable electronic equipment, iSuppli Corp. predicts.

Worldwide revenue from shipments of pow-er-management semiconductors will rise to $39.9 billion in 2011, a 59.6 percent increase from $24.98 billion in 2006. Semiconductors in this segment include voltage regulators, power-management ASICs and Application-Specific Standard Products (ASSPs), rectifiers, thyris-tors and power transistors.

“As sales of portable products like Portable Media Players (PMPs) and mobile handsets continue to rise, and the battery-life require-ments for such devices continue to toughen, demand is rising for more sophisticated pow-er-management solutions,” said Marijana Vu-kicevic, senior analyst for iSuppli. “This is a major factor behind the expected expansion of the power-semiconductor market over the next few years.”iSuppliCorporation,ElSegundo,CA.(310)524-4000.[www.isuppli.com].

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Antenna Solutions.pdf 7/9/07 3:26:46 PM

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18 PORTABLE DESIGN

cover featureembedded software

IntegratedStaticAnalyzers:

ANewBreedNew analysis tools enable you to catch more software bugs in less time.

byDavidN.Kleidermacher,CTO,GreenHillsSoftware,Inc.

MMany of the problems relating to loss of quality in software can be attributed to the growth of complexity that cannot be effectively managed. Security flaws are one example of the down-stream effect. According to Carnegie Mellon University’s Computer Emergency Response Team (CERT), the number of documented vul-nerabilities has been increasing almost expo-nentially, from approximately 400 in 1999 to more than 4000 in 2002 and more than 8000 in 2006.

A number of studies over the years have shown that the cost of detecting and correct-ing a software flaw increases dramatically as a project moves through the development, in-tegration, quality assurance and deployment cycle (Figure 1).

Increased complexity and cost of defect res-olution strain traditional reliability techniques such as code reviews and functional testing, im-plying a growing necessity for automated static

analysis tools that can find more flaws, and find them early in the development process. A num-ber of limitations, however, have prevented widespread adoption of static analyzers in ev-eryday software development. A recent survey of software developers showed that less than 5% make regular use of these tools. Develop-ers cited prohibitive execution time and lack of development environment integration as key inhibitors. A new breed of static analysis tool, called an Integrated Static Analyzer (ISA), uses a unique and innovative approach to address these barriers.

Static Analysis: How It WorksA static analyzer performs a full program

analysis, finding bugs caused by complex in-teractions between pieces of software that may not even be in the same source file. The analyz-er determines potential execution paths through the code, including paths into and across sub-

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AUGUST 2007 19

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routine calls, and how the values of program objects (such as variables or aggregates) could change across these paths. The following is a list of some of the more common errors that the analyzer will detect:

• Potential NULL pointer de-references• Access beyond an allocated area (e.g., array

or dynamically allocated buffer); otherwise known as a buffer overflow

• Writes to potentially read-only memory• Reads of potentially uninitialized objects• Resource leaks (e.g., memory leaks and file

descriptor leaks)• Use of memory that has already been deal-

located• Out of scope memory usage (e.g., returning

the address of an automatic variable from a subroutine)

• Failure to set a return value from a sub-routine

• Buffer and array underflows

Analyzers often have knowledge about how standard run-time library functions behave. For example, the analyzer knows that sub-routines like free should be passed pointers to memory allocated by subroutines like malloc. The analyzer uses this information to detect errors in code that calls or uses the result of a call to these functions. The analyzer can also be taught about properties of user-defined subroutines to enhance the efficacy and accu-racy of the analysis. One common feature of quality static analyzers is an ability to limit

the number of false positives so that develop-ers can minimize time looking at them. If an analyzer generates too many false positives, it

Costofsoftwareflaws.

figure 1

100

90

80

70

60

50

40

30

20

10

0Design Code/UT Integration Beta Test Post Release

Phase

Uni

t of

Cos

t

Configuration can often

be time consuming,

requiring days of

customization.

Webpageflawsummary.

figure 2

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20 PORTABLE DESIGN

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will become irrelevant because the output will be ignored by engineers.

Static analyzers commonly generate their results as a set of Web pages hosted by a Web server. The Web interface enables the user to browse high-level summaries of the different flaws found by the analyzer (Figure 2) and then click on hyperlinks to investigate specific prob-lems. Within a specific problem display, the error is usually displayed inline with the sur-rounding code, making it easy to understand (Figure 3). Results are easily shared between members of the development team.

IDE IntegrationCommercial static analyzers traditionally run

as separate tools, distinct from the tool chain used to develop and build application software. Thus, users must separately install, license and configure the analyzer. Configuration can often be time consuming, requiring days of customiza-tion in order to cajole the analyzer into process-ing the user’s particular dialect of source code.

A new type of analyzer, called an Integrated Static Analyzer (ISA), performs static analysis within the same compiler used to build soft-ware. Green Hills Software’s DoubleCheck is one example of an ISA. The ISA approach brings with it the obvious advantage of reduc-ing the time required to get useful results from the tool. In addition to the standard Web page reports, an ISA can generate its warnings or er-rors interleaved with the other standard diag-nostics output by the compiler. Furthermore, common development environment integra-tions between the project builder and the edi-tor augment the usability of the static analyzer: when a flaw is reported during the build pro-cess, the user can hyperlink from the builder’s output window back to the source code quickly, rectify the error, and then return to rebuilding the program (Figure 4).

Execution TimeCommercial static analyzers typically re-

quire orders of magnitude more execution time than a regular compile. Large software projects may require hours or even days of analysis

time. This execution cost presents a barrier to adoption. Static analysis, if used at all, may only be employed periodically or during test phases. Knowing that software development cost and time-to-market decrease when flaws are detected earlier in the project cycle, it fol-lows that static analyzers would be more ef-fective if execution time can be reduced to a level that encourages constant use. Developers can detect flaws while software is written and before it is ever committed to a configuration management system—certainly prior to quality assurance testing that may occur months after the software was first created.

Here again is where the ISA approach proves

beneficial. The ISA analysis engine takes ad-vantage of efficient dataflow analysis, constant propagation and path pruning algorithms devel-oped over many years to perform complex com-piler optimizations. The result is that the ISA executes much faster than traditional analyzers.

Secondly, the total time to build and analyze software is reduced since the tool uses a single parsing pass of the code to perform both com-pilation and flaw analysis.

Finally, the integration with the develop-ment environment enables the analyzer to take advantage of the system’s existing distributed

Context-sensitiveflawdisplay.

figure �

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AUGUST 2007 21

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build mechanism. The parsing pass for the proj-ect’s source code is distributed across available workstation bandwidth on the user’s network, dramatically reducing the total analysis time.

Case StudyAccording to apache.org, the Apache open

source hypertext transfer protocol (HTTP) server is the most popular Web server in the world, powering more than 70% of the Web sites on the Internet. The Apache Web server consists of approximately 150,000 lines of code. Double-Check was used to search the shipping Apache source code base for flaws.

The analyzer reported 140 flaws, including potential invalid pointer references such as the following from line 120 in Apache source file scoreboard.c:

ap_scoreboard_image = calloc(1,

sizeof(scoreboard) + server_

limit * sizeof(worker_score *)

+ server_limit * lb_limit *

sizeof(lb_score *));

Clearly, this allocation of memory could be substantial. It would be a good idea to make sure that the allocation succeeds before refer-encing the contents of ap_scoreboard_image. However, soon after the allocation statement, we have this use:

ap_score_board_image->global =

(global_score *)more_storage;

The de-reference is unguarded, making the application susceptible to a fatal crash. Another example can be found at line 765 in the file mod_auth_digest.c:

entry = client_list->table[idx];

prev = NULL;

while (entry->next){

/* find last entry */

prev = entry;

entry = entry->next;

...

}

Note that the variable entry is uncondition-ally de-referenced at the beginning of the loop. This alone would not cause the analyzer to report an error. At this point in the execution path, the analyzer has no specific evidence or hint that entry could be NULL or otherwise in-valid. However, the following statement occurs after the loop:

if (entry) {

...

}

By checking for a NULL entry pointer, the programmer has indicated that entry could be NULL. Tracing backwards, the analyzer now sees that the previous de-reference to entry at the top of the loop is a possible NULL refer-ence.

In addition to pointer problems, the analyzer discovered buffer overflows and reads of unini-tialized variables.

Coverity, who markets a traditional static analyzer, recently published a study of its tool’s analysis of the same Apache code base, report-ing an execution time of 10 minutes on a mod-ern PC. Using the same hardware platform, the DoubleCheck Integrated Static Analyzer required less than two minutes. Using the ISA’s distributed build feature, analysis time dropped further to a mere 30 seconds.

ConclusionStatic analysis represents a major new weap-

on in the software developer’s arsenal for bat-tling increasing complexity and its associated reliability, safety and security problems. The Integrated Static Analyzer approach makes it easy and efficient to incorporate automated static source code checking into the everyday software development process.

GreenHillsSoftware,Inc.

SantaBarbara,CA.

(805)965-6044.

[www.ghs.com].

Integrationofstaticanalysiswithprojectbuilder.

figure 4

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22 PORTABLE DESIGN

cover featureembedded software

TheMultimediaUserInterface:

ALookatThingstoCome

The success of any consumer electronic device depends to a high degree on having a flexible, intuitive user interface.

byNeilHenderson,GeneralMangerandGeoffKendall,ProductMarketingManager,EmbeddedSystemsDivision,MentorGraphicsCorporation

BBy now we all know about the Apple iPhone launch and the buzz it created. Why was demand so high for this particular product? One could ar-gue it’s the mystique behind the Apple brand; or the anticipation of a device with so much func-tionality. Both of these explanations might be correct, but let’s add a third reason: The promise of a radically new user interface (UI).

The truth of the matter is the success of any consumer electronic device depends to a high degree on its UI—how appealing is the inter-face and how easy is it to use. Get the UI wrong and the product has little chance of success. In fact, studies have shown that an attractive UI design encourages users to explore the full range of features, creates the perception that a product is easy to use, and even makes users more tolerant of a product’s shortcomings.

So if the benefits of a great-looking, easy-to-use UI are so clear, how come more products don’t have anything truly breakthrough to offer?

The answer lies in the fact that changing an embedded UI is not so easy. Even something as simple as migrating to a new screen size can cause major development headaches. To do something even more ambitious, say create a slick new interface that takes full advantage of the latest multimedia processor—is often not even a consideration.

It gets even worse as new features are intro-duced with each new product iteration. Time-to-market pressures mean that enhancements are often just “bolted on” to the UI rather than seamlessly integrated in an intuitive manner. Un-surprisingly, the result of such tactics is a market awash with products whose list of features might look convincing in a 30-second TV spot, but whose user experience ultimately fails to satisfy.

Finding an adequate solution to this prob-lem demands that we take a fresh new look at the role the UI plays in modern consumer electronic devices. By identifying common UI

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tors), support new screen sizes and languages, and exploit high-end hardware capabilities.

All such UI modifications are difficult to-day. Beyond the most basic visual adjustments (such as font color or background graphic), any change to the UI requires the application’s code to be modified, which can be time consuming and costly.

Clearly we need an alternative approach. If we could achieve a high degree of separation between a device’s UI and the functionality it relates to, we would be able to modify the UI freely with minimal complexity and risk.

An Alternative ApproachMuch of what we do when we interact with

a portable device can be boiled down to two things: browsing and selecting.

On a cell phone we might browse through the icons on our “home screen” and select the address book icon, and then browse through the list of contacts that appears to select the person we wish to call. Similar actions allow us to ne-gotiate messages in an inbox, scroll channels in a TV program guide, or visit favorites in an embedded Web browser. Using an MP3 player we navigate our play-lists, tracks, or artists via a series of lists/menus until we find the music

functionality and implementing it in a reusable, customizable way, we can make it far easier for designers and software engineers to deliver vi-sually engaging and easy-to-use products.

Creating UIs for Consumer Products Today

Most embedded application UIs today are constructed by laying out predefined controls on the screen, such as drop-down lists and check boxes. All of the UI logic—the “glue” that holds these controls together and makes them do useful things is generally implemented as part of the overall application code.

The upshot of this is that there is no clear separation between the UI (both its look and feel and its interactive behavior), and the un-derlying functionality it provides access to. The code for both the UI and the underlying functionality tends to be highly interdependent. It is this interdependency that makes it hard to modify a product’s UI. And the need to make such modifications is only increasing, as manu-facturers strive to improve ease of use, deliver a better look and feel to differentiate from com-petitors, integrate new features into an updated product, meet the diverse brand requirements of multiple customers (e.g., mobile phone opera-

Anapplication-centricUI(left),inwhicheachapplicationisresponsibleforitsowninterface,versusamenu-centricUIsystem(right),whereall“browseandselect”interactivityisdelegatedtoone,unified,extensiblemenusystem.

figure 1

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24 PORTABLE DESIGN

we want to play. Even while listening to a particular track we can control its playback (pause, rewind, etc.)

Even though these examples cover a range of functions and form- factors, what is happening at the interactive level is very similar. In each scenario, the user is being presented with (and asked to choose between) a number of options, which ultimately lead to a particular action being performed (e.g., a phone call is placed, an MP3 file is played).

All such activity could be managed by a single menu system, albeit an extremely flexible and generic one, capable of presenting a wide range of content in a wide range of ways from an equally wide range of sources. By taking this menu-centric approach, it’s possible to think of all the functionality on a device as being accessed in a consistent and unified way. This is quite a departure from the application-centric interface model that dominates the desktop environment (Figure 1).

Advantages of a Menu-Centric UIThe real power of the menu-centric approach is that the concept of what

constitutes a “menu” is highly abstract: it is really nothing more than a way to display one or more items that the user browses and selects. Lots of common UI constructs can be thought of in this way: a set of radio buttons is really just a menu in which only one item can be active; an “Are you sure?” mes-sage box is really just a menu with two selectable items, “Yes” or “No.”

Note that this notion of a menu focuses only on what is being displayed. It deliberately says nothing about how that information appears, or how the user interacts with it. We can exploit this degree of abstraction to

RapidUIchangeswithoutmodifyingtheunderlyingapplicationcode.

figure 2

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AUGUST 2007 25

cove

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Free to CreateWeallusethem,wealllovethem—

ourmobilephones,MP3players,TVmediacenters,in-carentertainmentcenters,Webappliancesofonetypeoranother.Theycandeliverdynamic,inter-activemediatouswhereverwego—thejoysoflisteningtoourfavoritesongonanMP3playerorseeingthefaceofarelativeliveonourphonescreen.Whenimplementedwell,thesensoryexperi-encemayseemeffortless,butunderthesurfacethedeliveryofmultimediacontentreliesonenormousprocess-ingpowerandsophisticatedsoftwarecomponents.

Attheheartofanymultimediadevice,youwillfindanincreasinglycomplexinfrastructurethatistime-consumingandcostlytodevelopandexploit.Siliconvendorsare,witheachgenerationoftheirchips,incorporatingbettermultime-diaprocessingcapabilities.Thenumberofmultimediastandardsforencodingaudio,videoandimagescontinuestoswell.IntegratingsupportforMP3audio,H.264video,JPEGimages,andanevergrowingrangeofothermediaformatsintoaproductisbecomingincreasinglydifficult.TheissueiscompoundedbythefactthateveryOSvendortypicallyhasitsownideaofwhatAPIamultimediacomponentshouldadhereto.Clearly,thetaskforeverysiliconvendor,devicemanufacturerandmultimediasoftwareproviderisnotgettinganyeasier.

EnterOpenMAX,aroyalty-free,cross-platformAPIthatprovidescomprehen-sivestreamingmediacodecandmediaapplicationportabilityacrossoperatingsystemsandsiliconplatforms.OpenMAXspecificationsandconformancetestsareproducedbytheKhronosGroup,amember-fundedindustryconsortiumbackedbymanyindustryheavyweights.OpenMAXhasalreadybeenadoptedbySonyinitsPlayStation3gameconsole,andlookssettobecomewidelyadoptedacrossthewholeindustry.

separate the UI description from the underlying functionality. This enables us to address a key requirement: the ability to completely change the look and feel and behavior of a UI without modifying the application code (Figure 2).

Apple’s iPod is an example of how a menu-centric approach has been employed to deliver a product whose UI is perfectly attuned to the device’s purpose. There are many reasons why the iPod enjoys the market dominance it does, but the simplicity and aesthetic appeal of its UI is surely one of them.

If an application wishes to utilize the menu system to display some data, all it needs to do is specify what items to display, what properties each item possesses and what actions to trigger when each item is selected. On receiving this data, the menu system can decide how to display it by reference to a UI description defined elsewhere.

The Inflexion Platform UI product from Men-tor Graphics takes just such a menu-centric ap-proach. It enables the appearance and interactive behavior of any menu (or “screen”) to be defined in terms of a simple XML-based template.

Each template describes not only what items and properties (or “fields”) should be displayed, but also how the menu’s appearance should change in response to user actions. Inflexion Platform UI automates many of the common interactive behaviors required by a consumer device, including hierarchical browsing, dis-play of rich content types, master/detail views and smooth scrolling so that highly sophis-ticated templates can be constructed rapidly without programming using only a PC-based design tool.

Multimedia CapabilitiesOnce a device’s UI layer is abstracted away

from the underlying functionality it exposes, it becomes far easier to incorporate new types of content within an application’s screens. To sup-port a new content type—such as video—all the UI technology needs to do is know how to dis-play it. Once this capability is present any such content—in this case, individual video clips—may be embedded into any screen design as eas-ily as a bitmap icon or a piece of text.

Inflexion Platform UI follows this approach, providing a plug-in API through which new “content players” may be hooked into the core engine. The Inflexion Platform Multimedia Feature Pack exploits this capability by provid-ing audio and video player plug-ins that allow designers to drop rich, multimedia content into their interface designs.

Once integrated into a product, such a video

component may be used to replace static icons with animated alternatives. Specific use models might include incorporating live channel pre-views within a TV program guide, or offering pop-up “multimedia help” to offer assistance in using a particular product feature. Such enhance-ments, while requiring no application coding, can greatly enhance the overall user experience.

To ensure interoperability with a broad range of third-party audio/video codecs, the Inflexion Platform Feature Pack utilizes a Nucleus-based implementation of the OpenMAX standard specified by the Khronos Group (see sidebar “Free to Create”). OpenMAX defines a cross-platform API that facilitates the delivery of portable and efficient multimedia components (including codecs) across multiple operating systems and hardware. Although it is a new standard, major silicon vendors have already begun to embrace OpenMAX, one example be-ing ARM who has announced support for the standard in its NEON product.

ConclusionTo maximize opportunities for success of

consumer electronic products, it is essential that the manufacturer focus on delivering a great looking and easy-to-use UI experience.

Today’s embedded UI technologies demand that for all but the simplest UI modifications, the device’s software stack must be altered. This is far from ideal, since such programming changes can be time-consuming, costly and in-troduce additional elements of risk when time-to-market pressures are already high.

This article describes one way in which the issue may be addressed; by re-thinking the role of the UI as it pertains specifically to consumer electronic devices and recasting it as a custom-izable, extensible menu system that can be uti-lized by underlying application code without being tied inextricably to it.

When such an approach is taken, it becomes far easier to re-brand a product’s UI, to custom-ize its interactive behavior, to modify its look and feel, and even to incorporate new types of content within it, such as video. Taking a menu-driven UI approach can improve the way consumer device UIs are created today, and can also make it easier for us to incorporate what-ever new types of device features and content may appear in the future.

MentorGraphicsCorporation

Wilsonville,OR.

(503)685-7000.

[www.mentor.com].

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26 PORTABLE DESIGN

wireless communicationswireless telemetry

Platform-Independent

SoftwareEnablesTrueInteroperabilityinZigBeeNetworksInteroperable hardware-independent software has been a challenge in building a ZigBee-compliant product. This no longer needs to be the case.

bySriniKrishnamurthy,VicePresident,StrategyandBusinessDevelopment,AirbeeWireless,Inc.

TThe need for a new wireless network technolo-gy designed to meet the unique requirements of sensors and control devices led to the develop-ment of ZigBee. Standards such as Bluetooth and Wi-Fi were unsuitable for low-power ap-plications because they deal with complex and power-hungry radio frequency integrated cir-cuits (RFICs) and protocols. Thus, the ZigBee Alliance was born. This industry consortium—now over 200 companies strong—was formed to evaluate the short-range, low-power IEEE 802.15.4 standard for potential use in mesh net-works made up of interoperable devices from different vendors. In 2004, years of work by the ZigBee Alliance finally paid off when they published the original ZigBee standard. Since then, numerous ZigBee devices have been de-veloped for a range of cost-effective, reliable, low-power wireless applications.

To date, application developers have relied on custom coding and point solutions to create

one-off closed applications. Many of these old-er, wired technologies have limited scalability, are tied to specific vendors/products, and end up being very expensive to maintain. Deploying large complex wired networks involving thou-sands of nodes is prohibitive, almost unimagi-nable. ZigBee mesh sensor networks based on global standards open the door for developing cost-effective and innovative solutions that can scale to large networks and still be affordable. The power of ad hoc mesh networking, coupled with low-cost battery-operated devices, creates opportunities for new real-time data-driven networked applications while enhancing op-erations and ongoing maintenance of existing wired solutions.

A low-cost microcontroller and an 802.15.4 radio are the main hardware components re-quired for building a ZigBee device, apart from the physical sensors that control and capture real-time sensory information as shown in Fig-

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Dream of Darkness, Wasteman!

atmel_PDesign_Feb07.indd 1 2/8/2007 9:10:02 AM

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Get Connected with companies mentioned in this article. www.portabledesign.com/getconnected

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is to research the latest datasheet from a company, speak directly with an Application Engineer, or jump to a company's technical page, the goal of Get Connected is to put you in touch with the right resource. Whichever level of service you require for whatever type of technology, Get Connected will help you connect with the companies and products you are searching for. www.portabledesign.com/getconnected

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Get Connected with technology and companies providing solutions nowGet Connected is a new resource for further exploration into products, technologies and companies. Whether your goal is to research the latest datasheet from a company, speak directly with an Application Engineer, or jump to a company's technical page, the goal of Get Connected is to put you in touch with the right resource. Whichever level of service you require for whatever type of technology, Get Connected will help you connect with the companies and products you are searching for.

www.portabledesign.com/getconnected

ure 1. While there are many providers of radios and controllers, interoperable hardware-inde-pendent software remains an overarching chal-lenge in building a ZigBee-compliant product.

ZigBee Networking Ad hoc wireless mesh sensor networks have

no fixed structure. Nodes join and leave at will. However, the intent to connect and communi-cate when announced creates a seamless mesh network using available nodes within range.

This just-in-time networking (JITN) is a fasci-nating challenge that is squarely met by Zig-Bee, as illustrated in Figure 2.

The resulting mesh sensor networks are com-plex and yet simple in functionality. Networking extends the data transmission range. Deploy-ments become more affordable by eliminat-ing wiring and installation costs. The potential monitoring and control applications for ZigBee within the commercial, consumer and industrial sectors are virtually limitless. ZigBee can meet the challenges that abound with interoperability, platform independence and network manage-ment solutions for large networks.

Elements of ZigBee Networks As seen in Figure 2, a ZigBee network is

made up of three types of devices—a personal

area network (PAN) coordinator; full function devices (FFDs), also known as routers; and re-duced function devices (RFDs), also known as end devices. Each type of device plays a spe-cific role in the network. Every device needs to be configured for its assigned role in the network through programmable options. The network stack provides a set of parameters for configuring the capability and other network operational characteristics. The configuration parameters for each of the devices are defined as part of network initialization. These param-eters are programmable, either at the factory or in the field.

The PAN coordinator is responsible for forming the network. There can be only one PAN coordinator in a single ZigBee network. Multiple ZigBee networks can be interconnect-ed through gateway and bridge devices. A Zig-Bee network can operate in 2.4 GHz, 868 MHz or 915 MHz license-free bands, depending on the chosen 802.15.4 radio. The PAN coordi-nator device scans and selects an operational channel within its range of frequencies in the selected frequency band. Each PAN is assigned a unique identification number, known as the PAN identity (PAN ID). After starting as a PAN coordinator, it allows other devices to join with it, forming a ZigBee network. Devices join the PAN coordinator either as routers (FFD) or as end devices (RFD).

The router plays a vital role in extending the network diameter to cover a larger geographi-cal area. Routers allow other routers and end devices to join with it, thereby extending the network. Routers also route data packets from other network devices to their intended des-tinations. Router do all the routing functions including maintaining routing table with active nodes, removing dead routes, flagging orphan nodes and dynamically switching to alternate routes when primary routes are unavailable.

The end device associates with a PAN coor-dinator or router as its parent in a ZigBee net-work. End devices cannot serve as a parent for other devices in the network; they are restricted to communicate only with/via their parent. However, it can communicate data to other remote devices through its parent, a router or a PAN coordinator. End devices are typically functional elements of the network. For exam-

SensorstoZigBeemeshnetworks.

figure 1

SensorBoard

Analog orDigital

Interface

Sensors

ZigBeeNetworkModule

802.15.4 Radio+ MCU + ZigBeeNetworking Stack

DigitalInterface

WirelessInterface

ZigBeeSensor

Network

Radiocrafts

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ple, a light switch is an end device in a lighting network application. The bulbs are routers in such a configuration.

Software Networking Architecture The software architecture for true platform-

independent interoperability is shown in Figure 3. The software adopts a layered architecture model, where each layer performs a specific set of services for its upper layer. Service access points (SAPs) provide the interface between layers. The upper layer accesses the data and management services of the lower layer through the respective SAPs. The lower layer uses these SAPs for sending confirmation and indication messages for the data and management services. The SAPs support a number of service primi-tives to achieve a predefined functionality.

The software is architected such that the physical layer is abstracted with all the hard-ware-specific functions of the underlying ra-dio as configurable parameters. In some cases, even the media access control (MAC) function is abstracted to accommodate for radios with built-in hardware MAC features. The upper layers (network and above) of the stack are designed to be oblivious to the existence of a specific hardware, enabling hardware indepen-dence and true interoperability in a multi-ven-dor ZigBee deployment.

The Right Play A pure-play software company with plat-

form-independent ZigBee stacks, tools and

TypicalZigBeenetwork.

figure 2

Desktop

PDA

Laptop

Cell Phone

ZigBee Coordinator (FFD)

ZigBee Router (FFD)

ZigBee End Device (RFD or FFD)

Mesh Link

Star Link

Back-OfficeEnterpriseNetworks

Platform-independentsoftwarenetworkingarchitecture.

figure �

ASP-SAP

NLDE-SAP

NLME-SAP

MLDESAP

MLME-SAP

PD-SAP

PLME-SAP

RF-SAP

DSP-SAP

DSP-SAP

Application Layer

ZigBee Applications1 to 240

UserApplications

ZDOSAP

APSDE-SAP

APSDE-SAP

APSME-SAP

ZigBeeDeviceProfile(ZDO)

Application Part Support Sub-Layer

Airbee-OS

Security Service Provider

Application Support Package Layer

Device Support Package Layer

Network Layer

MAC Layer

PHY Layer

RF-Transceiver

APPMailbox

NWKMailbox

MACMailbox

Application FrameworkTask

Scheduler

The software adopts

a layered architecture

model, where each

layer performs a

specific set of services.

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support is an excellent partner for building, de-ploying and maintaining a successful ZigBee network. Using platform-independent ZigBee software enables original equipment manufac-turers (OEMs) and integrators to use any IEEE 802.15.4-compliant radio (from TI, Ember, Atmel, ZMD, Freescale or others), gives the freedom to choose any controller (from TI, In-fineon, Atmel, Freescale, Renesas, Intel, Atmel or others), and allows the choice of any real-time operating system (RTOS) for building a ZigBee network.

ZigBee networking is software-intensive and requires networking experts in the custom-er domain as well. End-user engineers usually focus on their business application, while the ZigBee networking software providers focus on optimizing the myriad options in the ZigBee protocol to ensure the combination of hardware and software that is the most cost-effective and high performance for the application. Deploy-ing complex ZigBee networks with hundreds and eventually thousands of nodes requires software tools and support. A network-manage-ment framework that can be customized to de-ploy, monitor, control and manage—essentially keep the network humming at all times—is one such essential tool. Ongoing software sup-port is critical during the lifecycle of a ZigBee network and in particular during deployment, where unknowns abound in a crowded and of-ten competing RF environment.

ZigBee devices need to become platform-in-dependent for true interoperability and vendor independence. The opportunity is ripe for OEMs and integrators to bring compelling products to market quickly and at low cost—today. The first large-scale ZigBee deployments will be in energy management, followed by building au-tomation, industrial plant monitoring and home control. The technology is proven, with many initial ZigBee pilots, test networks and initial deployments already underway. The year 2008 will be the year of the solution, when ZigBee implementations finally take off.

AirbeeWireless,Inc.

Rockville,Maryland.

(301)517-1860.

[www.airbeewireless.com].

Untitled-5 1 7/31/07 2:26:09 PM

ZigBee devices need

to become platform-

independent for true

interoperability and

vendor independence.

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Mouser and Mouser Electronics are registered trademarks of Mouser Electronics, Inc. Other products, logos, and company names mentioned herein, may be trademarks of their respective owners.

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32 PORTABLE DESIGN

consumer electronics

D

Wide Dynamic Range Imaging

TechniquesA high-resolution image sensor is only the start of the story. How you process its output will ultimately determine image quality.

by Venkata Raghavan S., Product Applications Group Lead Memory and Imaging Division, Cypress Semiconductor

Digital imaging technology has progressed from digital still cameras into an array of por-table applications such as cellular handsets, where it serves as a differentiating feature. In applications such as automotive sensors and medical equipment, digital imaging serves as the foundation of higher-order functionality such as machine vision, instrumentation, docu-ment scanning, motion analysis and scientific high-speed image analysis.

Image resolution is often seen as the most important factor determining the quality of an image. However, in all of these applications, from those that produce images for viewing or perform complex analysis of images, dynamic range plays a key role in determining how ef-ficient and effective later imaging processing will be. Dynamic range directly affects final image quality as well as the effectiveness of any compression or analytics technologies.

The dynamic range of CMOS image sensors

is defined by their ability to capture dark as well as bright sections within an image while maintaining the highest fidelity. Real-life im-ages have varying illumination levels through-out a scene. An image sensor must have wide dynamic range (WDR) in order to capture all the illumination levels (contrast) of an image. The wider the dynamic range of the sensor, the more illumination levels that can be captured.

The key to achieving sufficient WDR is iden-tifying the dark and bright portions of the im-age and controlling the integration of the pixels to avoid saturation. Pixels impinged with high illumination need saturation control, while pix-els impinged within the dark portion of the im-age need longer integration times. In this way, the contrast of the scene can be restored by the imager. This article describes the definition of wide dynamic range and appropriate imaging techniques to use with CMOS image sensors.

image sensors

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Dynamic RangeDynamic range is the ratio of the maximum

signal output of the sensor to the smallest sig-nal output of the sensor. The higher the dynam-ic range of the sensor, the greater the fidelity of the optical image transformation from the object scanned. The sensor generates its maxi-mum output for brighter portions of the image and its minimum output for darker portions. The maximum output of the sensor without saturation is limited by the well capacity of the photo diode, while the minimum detectable output is limited by the noise floor of the sen-sor. Figure 1 illustrates the noise floor in detail, where dynamic range (db) = 20 log (sensor’s maximum output / sensor’s minimum output).

A higher dynamic range results in a better transformation of the object to an image, accu-rately capturing the varying light intensities of a scene, from the brightest to the darkest parts, including shadows. Factors that affect dynamic range include:

• Dark current of the sensor • Saturation of the pixels • Quantum efficiency/well capacity of the

photo diode

Signal-to-Noise RatioThe signal-to-noise ratio (SNR) is a measure

of a captured image’s immunity to noise. SNR is the ratio of the peak light intensity without saturation to the scene background noise. A camera with a higher SNR typically produces low noise video in darker scenes. Photodi-odes generally have better SNR when they are charged to more than half of their total capac-ity. However, they cannot be charged beyond saturation.

There are two basic noise sources in a CMOS image sensor:

1. Temporal noise caused by the photo diode and MOSFET, shot noise, thermal noise and 1/f noise as envisaged in electronic circuits.

2. Fixed pattern noise caused because of the pixel output variation for the same illumi-nation. The source of fixed pattern noise are device and interconnect mismatches.

Figure 2 shows a three-transistor APD pixel circuit widely used in CMOS image sensors.

The first MOSFET is used to reset the photo di-ode to a known voltage by pulsing the gate (re-set) signal. The photo diode’s stray capacitance is charged to a known voltage (reset voltage) and the photo diode is allowed to integrate the charge. Due to electron hole re-combination, the reset voltage is pulled down, depending upon the light intensity impinging on the photo diode. If the pixel is saturated, the whole charge across the photodiode will be depleted completely. The second MOSFET is a source follower, while the third MOSFET switches the selected row/pixel to the bit line, which in turn is connected to the column amplifier. The actual voltage integrated

Sensorop

MaximumSignal

Photon Noise

NoiseFloor

NoiseSignal Photons Log Scale

10 100 1,000 10,000

Dark/Readnoise

Noise floor definition of the CMOS image sensor.

figure 1

Three-Transistor pixel.

figure 2

Barrier(Reset)

Reset Vdd

RowSelect

Output(to CDS/ADC)

Vdd

AUGUST 2007 33

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by the photo diode is the reset voltage minus the voltage across the diode after integration.

Hence the photo diode is operated with one reset for one integration cycle. This method is called linear integration (open loop with no con-trol of saturation of the pixel). If the photo diode needs saturation, control multiple resets are ap-

plied with varying integration times optimally chosen for the end application to achieve a wide dynamic range. The first reset voltage would be the largest voltage level as per the design, and second, third and so on will be smaller voltage levels.

The steps involved in the multi-reset

system are: 1. Reset the photo diode with the maximum

reset voltage VR1 allowed and allow in-tegration time T1.

2. Reset the photo diode with smaller voltage VR2 (voltage less then VR1). With this re-set voltage, the pixels saturated will have a

source of the MOSFET less than the drain, and the MOSFET will conduct a voltage across the photo diode equal to the new re-set voltage. If the pixel is not saturated, the source voltage will be less than VR2 and the MOSFET will not charge the photo di-ode to the new reset voltage. The photo di-ode will continue integration with time T2. This pixel corresponds to the dark portion of the image and receives more integration time, which is desirable.

3. The resets are repeated until the last bar-rier (reset) voltage completes the integra-tion.

Pixel Response with Multi-Barrier Operation

Pixels impinging with the brighter portion of the image are reset and pixels impinging with the darker portion receive more integration time to develop the charge. In this way, the saturation is controlled.

Parameters of control to achieve dynamic range:

• Integration time • Barrier voltage (reset voltage is also called

barrier voltage)Two-barrier reset timing.

figure 3

BrightResponse

MediumResponse

DarkResponse

B2

B1

V

T1

T2

T

Integration (T=T1+T2)

By choosing a suitable combination

of barrier voltage and integration time, the desired

wide dynamic range can be achieved.

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By choosing a suitable combination of bar-rier voltage and integration time, the desired wide dynamic range can be achieved.

The three-transistor pixel (Figure 2) allows multiple resets and integration time control. External circuits are required to detect the sat-uration and reset the pixel. Also required is a compression/transfer function table to decide the barrier voltage and integration times. In this way, the required dynamic range can be controlled and achieved based on the end ap-plication.

Achieving Wider Dynamic RangeTechniques to achieve wide dynamic range

include: • Double shot exposure. To increase the dy-

namic range of an image, pixels are inte-grated two times, once with a shorter inte-gration time to capture the brighter portion of the object scanned, and again with a longer integration time to capture the dark-est portion of the object scanned. The final image is comprised of the two frames of data through signal processing.

• Multiple image detectors. Using this ap-proach, multiple detectors capture the same scene at the same time using beam splitters to project multiple copies of the same image onto each detector at the same time. Each detector is preset for a predeter-mined exposure time (electronic control) or optical attenuators (optical control). This method is suitable for generating high dynamic range images in real time. Additionally, the camera or the scene can be moving during scanning.

• Saturation detection per pixel. Each pixel of the CMOS array has a saturation de-tection circuit, such as a comparator, to compare for a known voltage across the diode to detect and reset in case of satura-tion. This approach imposes the overhead of a saturation detection circuit per pixel, which is too expensive for large pixel ar-rays.

• Multi-reset with different integration times. Pixels based on an APD as described in Figure 2 can be reset several times dur-ing the integration period. The minimum requirement is to have two barriers (reset

voltages) with different integration times. Again, the first barrier would be larger than the following barrier. The second bar-rier voltage can be selected based on the well capacity and the previous integration output (Figure 3).

Dynamic range is one of the important fac-tors affecting the image quality of CMOS sen-sors. The wider the dynamic range, the better a digital imaging system will be able to accu-rately capture the varying light intensities of a scene. By varying the combination of barrier voltage and integration time, as well as apply-ing different techniques to widen the dynamic range, developers can exercise more accurate control of image quality across a broad range of imaging applications.

Cypress Semiconductor, San Jose, CA. (408) 943-2600. [www.cypress.com].

Images illustrating (a) linear and (b) multi-slope integration as captured by an IBIS-5 image sensor

from Cypress Semiconductor.

figure 4

a)

b)

AUGUST 2007 35

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portable power

M

Powering Backlights in

Portable DevicesAdvances in backlight technologies and techniques mean you can have more of your power budget to design with instead of write off.

by Tomi Koskela, Applications Engineer, Power Management Division, National Semiconductor Finland

Most portable electronic products such as mo-bile phones, PDAs and navigation systems have small-format LCD displays that need backlighting. Viewing high-resolution photos, video and Web pages has increased the utiliza-tion time of handset displays. The demand for high-quality displays is increasing in devices with media access. This creates challenges for backlight LEDs and also for the drivers. White backlight LEDs dominate the market, but the new RGB backlight will improve color satura-tion on displays.

The keypad backlighting and other cosmetic lights are commonly used for personalizing mobile phones. There are different require-ments for the display backlighting and keypad backlighting, and this affects the way these LEDs are driven.

Changes in LED and Li-Ion battery technol-ogies will affect the backlight driver design. In-creases in LED count on portable devices cre-

ate challenges for the LED drivers. The most common challenges in driving backlights in portable devices are power efficiency, control interface/programmability, solution size, EMI and system cost.

Brightness ControlThe brightness of backlight LEDs can be

controlled by pulse width modulation (PWM) or by constant current controls. PWM bright-ness control needs a constant-current driver to drive the LED, but its on/off time is controlled to achieve the desired brightness. This makes PWM slightly more complex than direct con-stant-current control.

One good thing about the constant-current control is that there is no continuous switching, which results in low EMI. The down side is that the LED color spectrum shifts when brightness is adjusted. LED manufacturers group and bin the LED at certain grouping currents and then

powering displays & backlights

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guarantee the specifications with this so-called grouping current. When the current is moved outside the grouping current there will be more variation in the LED brightness than specified. This is visible as a difference in brightness be-tween backlight LEDs, especially when very low current is used.

With PWM control the brightness adjust-ment is linear through the whole range, and there is no color change when the brightness is adjusted. However, PWM switching can gen-erate EMI and audible noise. Audible noise is caused by piezoelectric effect on the ceramic capacitors. X5R, X7R and similar capaci-tors have barium titanate dielectric, which is a piezoelectric material. To get rid of the au-dible noise, the PWM frequency has to be high enough that the human ear cannot hear it, for example 20 kHz. Another alternative is to use such a low frequency that the capacitors and the PCB in the application do not resonate; but the frequency must still be high enough that flickering is not visible (e.g. 250 Hz). EMI can be reduced by slowing down the rising/falling edges of the PWM control.

Backlight Driver TopologiesDriver topologies can be divided into paral-

lel and serial types. Parallel driving is typically used when each LED requires individual con-trol. In backlighting schemes where all LEDs must be the same brightness, there can be a slight mismatch between LED currents with parallel drivers. However, with the latest driv-ers the current mismatch is negligible because the typical LED brightness tolerance is much greater than the mismatch in output currents.

When the backlight LEDs are connected in series the same current flows through all LEDs, so the matching at LED currents is per-fect. PCB routing is easier with serial driving, because there is no need for individual trace from the driver to each LED. The LED drive efficiency with serial driving can be considered to be slightly better than with parallel driving, because the driver output’s forward voltage is taken into account for several LEDs. Serial driving needs a high voltage boost converter (e.g. 20V) to get enough voltage from the Li-Ion battery to drive several LEDs in series.

The most common method for driving an

LED is to use low side driver outputs, where the LED output pin acts as a constant current sink. In this case the LED output and supply voltage need separate routing to the LED. With high side driver where the LED output pin is current source, only the LED pin needs rout-ing, and the LED cathode is connected directly to the GND. Usually there is a GND plane in the PCB, so no separate routing is needed. Ex-amples of different driving methods are shown in Figure 1.

White LEDs and Battery Technology

Portable devices are typically powered with a single cell Li-Ion battery, with voltage be-tween 2.8-4.3V depending on its charge. White LED forward voltage is typically 3.5V. The single cell Li-Ion battery voltage therefore is not always enough to drive the LEDs and a step-up DC/DC converter is needed. A convert-er can be either capacitive (charge pump) or inductive (magnetic boost). A charge pump is typically used for parallel LED drivers because of its small solution size. A magnetic boost converter is used for high voltage serial LED drivers, since with charge pump technology it is difficult to achieve high enough output volt-

Examples of parallel high side and serial low side drivers.

figure 1

AUGUST 2007 37

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38 PORTABLE DESIGN

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age. Converter output voltage adjustment can be either automatic (adaptive) based on LED forward voltage sensing, or the user can set the constant voltage based on the LED forward voltage specification.

In the future, new Li-Ion battery and LED technology will bring new challenges to the LED driving. With new chemistry the battery voltage range will be about 2.3V-4.7V. The typical white LED forward voltage will drop to about 2.9V. At the same time output driver saturation voltage is going to drop as well. To drive 2.9V LEDs efficiently without burning too much power on the driver, it might become necessary to use buck-boost type converters to provide supply voltage for LEDs when parallel driving is used. Figure 2 shows the effects of the battery, driver and LED technology prog-ress.

RGB LED BacklightingTypically, a small panel LCD display back-

light is implemented with a couple of white LEDs. The problem with white LEDs is that their spectrum is not ideal for photographic reproduction. This is caused by the fact that white LEDs are basically blue LEDs with yel-low phosphor on top. The spectrum has two

Battery and white LED forward voltage progress.

figure 2

Voltage (V)

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.25

_

_

_

_

_

_

_

_

_

_

_

_

Excess Voltage

ChargingCharging

BUCK?

1X

Boost

1X

1X

Boost

VF=3.5V

VF=2.9V

VDRIVER

=0.4V VDRIVER

<0.2V

Today “Tomorrow”

BAT

TER

Y

Typical White LED vs. RGB LED spectrum.

figure 3

BlueChip

RGBChips

400 500 600 700nm

400 500 600 700nm

+ +

+1 Phosphor

Emission Wavelength

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peaks, one at blue and a second at yellow. Typi-cal white LED versus RGB LED spectrum can be seen in Figure 3.

Pixels in LCD displays are divided into cells of three primary colors: red, green and blue. Pixel color is defined by mixing the three pri-mary colors. To filter the right color to each color cell, color filters are used. Color filters waste a big part of the optical power, and even after color filtering, the color spectrum passing through the LCD is not ideal. With white LED backlighting it is possible to produce up to 75% of National Television Standards Committee (NTSC) colors on an LCD display (the red end of the conventional LCD display is especially limited). When RGB LEDs are used for LCD display backlighting, the color reproduction can be adjusted to cover over 100% of the NTSC color gamut, which results in brighter colors and better picture quality. With optimized color filters, less power is wasted than in white LED backlighting. Structure of an LCD display can be seen in Figure 4.

With RGB backlighting the driver must cor-rect the brightness balance between the primary colors (red, green and blue) when the LED tem-perature changes to avoid white point shifting. The driver must also keep the light intensity ad-justed correctly at any operating temperature. Compensation can be either closed-loop or open-loop. With closed-loop compensation an optical sensor is used for measuring the white point and intensity. With open-loop compen-sation the temperature is measured, and pre-defined compensation curves are used to adjust the brightness balance.

An example of a RGB backlight driver is National’s LP5520, which is an open-loop compensated LED driver. The principle of open-loop color compensation is illustrated in Figure 5. The temperature compensation curves are measured for the actual RGB LED type used in the application, and these curves are programmed to the chip’s internal EEPROM memory. The chip is integrated into the LCD display module, and the module manufacturer programs compensation curves in production. A RGB LED backlight optimized color filter is used as well.

Keypad Backlighting and Other Cosmetic Lights

Keypad backlighting has some specific re-quirements compared to display backlighting. The color wanted in keypad backlighting is not necessarily white; it can be basically any color. The trend is today that the keypad backlighting

and other cosmetics lights in portable devices are used to produce some light effects. Display backlight control is usually the on/off type with possible smooth fade in/out, but cosmetic light control is more complex. By using RGB LEDs for keypad backlighting it is possible to change the color and the whole appearance of the de-vice by simply changing the brightness balance between the red, green and blue LEDs. This gives interesting possibilities for personalizing handsets and other portable devices with soft-ware control.

For complex lighting sequences such as smooth transition between different colors, a sophisticated control method is required be-sides a simple enable control pin. An I²C con-trol bus is widely used in many portable devices as it provides great flexibility for controlling an LED driver via only two wires. Usually there are other components, for example a camera

Structure of an LCD Display.

figure 4

Color Filter Substrate

Polarizer

Black Matrix Color Filter Cell(red, green, or blue)

TFT Capacitor

Thin Film Transistor Array Substrate

Polarizer

Polychromatic Backlight

TransparentCommon Electrode

TransparentPixel Electrode

L i q u i d C r y s t a l

AUGUST 2007 39

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module, using the same bus. Therefore, LED control should not use all of the I²C bandwidth. Controlling the LED brightness in real time creates considerable I²C traffic.

New LED drivers such as National’s LP5521 allow minimum real-time control by incorpo-rating internal memory and an execution engine for lighting sequences. Lighting sequences are written to an internal memory after power-up,

and then an external trigger pin or I²C write is used to start the sequences. When the sequence is running, processor control is not required. When the phone is in standby mode, the appli-cation processor can be put in sleep mode, and the LEDs can be still running complex lighting sequences. Sequences can include time delays, ramps, blinking, loops and sending/receiving of trigger signals.

To further decrease power consumption the latest LED drivers have automatic power-save-mode operation. The DC/DC converter is started only when the Li-Ion battery voltage is not sufficient to supply the LEDs. The driver also shuts down any unused functions when the LEDs are not active and while the sequence is running internally. This significantly decreases average current consumption.

With small LED driver solution size, it is possible to create a localized, rather than cen-tralized, lighting solution, meaning that the LED drivers are located near the LEDs. This way the PCB routing is a lot easier, and the EMI is reduced. Drivers that are designed for a localized solution have external control pins, which are used for synchronizing several driv-ers, making it possible to achieve very interest-ing lighting effects.

ConclusionThere are several possible driver topologies

for driving backlight LEDs. Choosing the right one depends highly on the application. The up-coming new Li-Ion battery technology together with lower forward voltage white LEDs create new challenges to the drivers.

RGB LEDs can be used for LCD display backlighting on high-end phones and other por-table devices where high display image quality and color reproduction is essential. With RGB backlighting it is also possible to reduce power compared to white LED backlighting when the right kind of driver, LEDs and color filters are used on the display module.

Programmability is the key feature in the lat-est keypad backlight drivers. It provides easier control, and also enables power savings when application processor control is not needed during lighting sequences. Programmable LED drivers also create interesting possibilities for personalizing handsets.

National Semiconductor Corporation, Santa Clara, CA. (408) 721-5000. [www.nsc.com].

Principle of the open-loop color compensation.

figure 5

Brightness Control(I2C/SPI or external PWM)

Average PWMLogic

LEDDrivers

PWM

PWM logic reads ambienttemperature and compensates

R, G, and B LED intensity bychanging PWM duty cycle

(12-bit resolution)

ADC

EEPROM

Compensation curvesare programmed by

display module makerthrough serial interfaceto the EEPROM memory.

TemperatureSensor LEDs

T

Integrated To One Chip

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42 PORTABLE DESIGN

product featureConfigurable Video Subsystem Targets Portable Devices

by John Donovan, Editor-in-Chief

Last year ARC threw its hat in the mobile phone ring when it introduced the AV 401, a low-power multimedia subsystem that could decode standard-definition (SD) video and a variety of audio formats. This month ARC upped the ante, introducing five new subsystems targeting multi-standard video-capable devices in applica-tions ranging from low-resolution image sensor modules to high-end cell phones, set-top boxes and DVRs, including high-quality H.264 encode and decode. ARC claims its high-end AV 417V subsystem is the smallest programmable SD solution on the market.

Based on the recently introduced VRaptor Multicore Architecture, each is programmable; encodes and decodes a wide range of popular video standards; and comes with optimized media processing elements including: a configurable ARC 700 core; up to two 128-bit SIMD Media Proces-sors; a dual-channel media-optimized DMA engine; separate multi-standard encoding and decoding accelerators; programmable motion estimation accelerator; and SoC development tools. ARC

includes a full range of optimized audio and video codecs that can encode and decode pretty much every format that isn’t moribund or defunct.

The VRaptor architecture is a scalable hetero-geneous processor design that puts a lot of horse-power in a small piece of silicon. VRaptor provides three distinct classes of ARC core modules. The first is a configurable 700 family core and a range of specialized SIMD multimedia processors optimized for functions such as low-pass de-block-ing filters and pixel transforms. The second class includes accelerators, such as entropy encoders and decoders and motion estimators; these per-form multimedia processing tasks more efficiently than general-purpose, programmable cores. The third class includes high-speed DMA controllers

to relieve the CPU from complex data movement often found in multimedia codecs.

Since they are both configurable and program-mable—enabling design differentiation and reuse—ARC is positioning its subsystems as the logical alternative between fixed function blocks on the one hand and general-purpose DSPs on the other.

Still, why should designers care about doing H.264 encoding—a seriously power-hungry process—on a cell phone? ARC’s answer is, “YouTube.” What good is a high-resolution image sensor if the output is only encoded to display on a tiny CIF screen? If you want to share your videos with Aunt Alice in Atlanta via email—or on your couch via your HD-TV—you need to do high-quality video encoding. ARC claims to do 30 fps low-power H.264 encoding, normally a power-hungry process. One power saving technique is dynamic encoding, which continuously evaluates system resources and adaptively applies different processing resources to achieve the optimum result. For example, dynamic encoding allows the designer to adjust the encoding process in a phone with a fully charged battery versus one running close to empty.

Despite its “low-power” claims, ARC is reluctant to release power figures for its new processor family. This is frustrating to reviewers, though understandable to anyone who is familiar with the amount of “specmanship” in the IP industry. Still, how do you evaluate their claims? A good indirect estimate comes from the size of the module—10.27 mm² in a 130 nm TSMC G process using Virage libraries. ARC claims its modules can do H.264 BP encoding of D1 video, processing a 10 Mbit/s bitstream at 30 fps at under 200 MHz; it can decode the same bitstream at 1.5 Mbits/s at under 160 MHz. If they can claim low power at 130 nm, what happens when you go to 90 or 65 nm?

For comparison’s sake, ARM’s Coretex-A8, de-signed for “power-optimized mobile devices need-ing operation in less than 300 mW,” needs to run at 350 MHz to decode H.264 video at 30 fps. And the A8 is built for a TSMC 65 nm LP process using Artisan libraries; a speed-optimized Coretex-A8 capable of running at 650 MHz results in a “<4 mm²” core (area with cache). If you assume that active power is roughly halved if you reduce chip area by 2x—by moving from 130 nm to 65 nm, for example—and if you further assume that running a chip at half speed will reduce the active power by half—the ARC subsystem would seem to compete well with the A8 in terms of both power and performance. Core area, frequency range and power consumption are of course dependent on processes, libraries and optimizations; and lacking spec sheets, we’re clearly in no position to make a definitive comparison between these two chips. But right now one editor’s educated guess is that ARC may just have a winner on its hands.

figure

Integrated Software

Standard Definition EncodeH.264 BP Encode under 200MHzH.263 MPEG-4 SP/ASP Encode

JPEG Encode

Standard Definition DecodeH.264 BP Decode under 160MHz

VC-I DecodeMPEG-4 (ASP, SP) Decode

MPEG-2 Decode,MJPEG, JPEG, GIF, PNG,

TIFF Decoders

Audio CodingMP3, WMA, AAC, aacPlus v2,

AC3, Dolby Digital Plus

SIMD MP #1128-bit

Hardware Platform

SIMD MP #2128-bit

ARC 700 CPU

InstructionCache

DataCache

System Bus I/F

EntropyDecode

(ED) VideoOptimized

DMA Engine

MotionEstimation

(ME)

EntropyEncode

(EE)

Channel

Loca

l Scr

atch

pad

Mem

ory

(SD

MI)

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44 PORTABLE DESIGN

products for designersLow-Power Wireless USB Chip Integrates PHY, MAC

Wisair is sampling its new WSR601, a single-die CMOS chip for both host and device Wireless USB applications. The production-ready chip, based on WiMedia and Certified Wireless USB standards, integrates UWB PHY (including RF), MAC and Wireless USB subsystems. The WSR601 combines high performance and low power consumption to offer a cost-effective solution for a wide range of Wireless USB applications, including battery-powered, portable devices.

Implemented in digital CMOS process, the WSR601 supports HWA, DWA and Native device protocols, and features SDIO and USB interfaces, isochronous data transfer and cable and numeric association models.

With unique PHY capabilities, the single chip delivers full-room coverage with connectivity ranges of 8 meters at 480 Mbits/s and over 20 meters at 200 Mbits/s. For mobile devices where battery life is key, the WSR601 provides power-save modes and an aver-age power consumption of 385 mW at 100 Mbit/s throughput.

A two-wire coexistence scheme allows the WSR601 to coexist in close proximity to other radios

such as Bluetooth and 802.11. The chip’s low out-of-band emission, below -70 dBm/MHz, provides the flexibility to support Japan regulatory requirements without the need for a dedicated external filter. Additionally, integrated Detect & Avoid technology enables the WSR601 to coexist with other wireless technologies sharing the same spectrum, such as WiMAX.

The WSR601 is currently sampling, with production volumes expected in Q4 2007. BOM costs for an HWA are expected to be below $15 in production quantities. For additional chip information please refer to www.wisair.com/products/chipset/wsr601/.

Wisair, Campbell, CA. (408) 370-4727. [www.wisair.com].

High-Performance NAND Controllers for Mobile Storage Applications

SST (Silicon Storage Technology, Inc.) has announced that it is expand-ing its NAND controller offerings with two new NAND controllers, the ATA Flash Disk Controller (SST55VD020) and the CompactFlash Card Control-ler (SST55LC200). Featuring an advanced error correction code (ECC) engine, these high-performance controllers are designed for managing current and future high-density NAND flash requirements.

SST SuperFlash-based embedded firmware allows for firmware updates before, during and after manufacturing. Firmware update functions elimi-nate the need to redesign or re-qualify new controllers to meet the requirements of new NAND flash technology introduced after the system has been put into pro-duction. This allows system manufactur-ers to optimize NAND costs, availability and performance requirements in the face of fast-changing NAND technologies.

With an Ultra-DMA host interface and intelligent NAND flash interface, the new NAND controllers can operate up to 30 Mbytes/s for both sustained write and read operations. Both controllers also directly support up to eight chip-en-ables for NAND devices. In addition, the SST55VD020 ATA Flash Disk Controller can support up to 64 chip-enables for NAND devices with external decoding logic and drivers.

Ideal for products with size constraints such as music players, portable multimedia players and camcorders, the SST55VD020 is offered in a very small 6 mm x 6 mm x 0.85 mm 85-ball VFBGA package. Both the ATA Flash Disk Controller and the CompactFlash Card Controller are also available in a 100-pin TQFP package. The ATA Flash Disk Controller is also compliant to industry standards ATA-4 supporting PIO-4, MWDMA-4 and UDMA-4. The CompactFlash Card Controller is compliant to CFA 3.0 sup-porting PIO-6, MWDMA-4 and UDMA-4.

Samples of the SST55VD020 and the SST55LC200 controllers are available now. Pricing starts at $3.12 in 100K unit quantities.

Silicon Storage Technology, Inc. (SST), Sunnyvale, CA. (408) 735-9110. [www.sst.com].

Power-Efficient DSP Platform FPGAsXilinx, Inc. has announced the addition of power-efficient Spartan-3A DSP devices to its XtremeDSP portfolio of solutions for signal processing

applications. The new devices, which are in production today, deliver high-performance DSP capabilities in a low-power FPGA for applications such as tactical radios for military communications, wireless access points and portable medical equipment.

Spartan-3A DSP low-power (LP) devices deliver a 50% static power savings, and a 70% savings while in suspend mode, compared to the standard devices. The lower power complements the dynamic power advan-tage inherent in the Spartan-DSP series due to the integration of dedicated DSP circuitry. The Spartan-3A DSP 3400A LP devices have a 25% power efficiency advantage over competing FPGAs by delivering 4.06 GMACs/mW at a speed of 250 MHz in the lowest-cost speed grade.

The Spartan-3A DSP FPGA platform’s ability to perform signal processing functions without the need to consume logic resources enables designers to meet their performance and cost goals while enabling better power efficiency. The XtremeDSP DSP48A slices that make up the dedicated DSP circuitry include dedicated 18 x 18 multipliers along with 18-bit pre-adder and 48-bit post-adder/accumulator to deliver superior perfor-mance of DSP functions at a low cost.

The Spartan-3A DSP LP devices can be used in applications such as ultra portable ultrasound equipment, where digital beamforming is a key DSP application and channel counts vary from 16 to 128 depending on

system requirements. The suspend mode capabilities of the Spartan-3A DSP FPGA platform also help to extend battery life in these applications. Other applications that can benefit from the industry’s lowest-power/high-performance FPGA platform include MILCOM portable and mobile tactical radios, and portable night vision equipment.

The XC3SD1800A-4LI (low power, industrial temperature grade) device is priced at $34.80 and the XC3SD3400A-4LI device is priced at $50.00 Pric-ing is for 25,000 units in volume production, end 2008.

Xilinx, San Jose, CA. (408) 559-7778. [www.xilinx.com].

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ucts

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Load Switches Offer Improved Thermal Dissipation in PortablesFairchild Semiconductor’s FPF214X and FPF216X series of IntelliMAX advanced load switches feature superior

thermal performance and full system protection for portable applications operating between 1.8V and 5.5V. Available in a 2 mm x 2 mm green-compliant MicroFET MLP package, this new series offers 45 percent en-

hanced thermal performance compared to traditional SOT-23 packages. These highly integrated advanced load switches simplify design, reduce component count and minimize board space by integrating a 0.11 ohm current-limited P-channel MOSFET with protection and control features, including thermal shutdown, controlled turn on, reverse-current blocking and under-voltage lockout (UVLO).

Key features of the FPF214X and FPF216X series include: • Ultra-compact and thermally efficient 2 mm x 2 mm MLP packaging that improves thermal dissipation by 45

percent. • Power “Good” signal to indicate stable output power signal for software management in power-sequencing applications. • Integrated current limiting with fast limiting response time (5 µs for nominal over current conditions) with fixed (up to 400 mA) and adjustable cur-

rent-limit options (up to 1500 mA). • Additional reverse-current function to protect against reverse-current flow conditions in accessory or battery-powered applications.

Samples are available now. Pricing is $0.72-.78 in 1,000-lot quantities.

Fairchild Semiconductor Corporation, South Portland, ME. (207) 775-8100. [www.fairchildsemi.com].

Mobile TV SoC for ISDB-TNewport Media is sampling the

world’s first complete single-chip solu-tion for the mobile version of Japan’s Integrated Services Digital Broadcast-ing-Terrestrial (ISDB-T) digital televi-sion standard. The NMI320 Sundance J mobile digital TV receiver integrates an RF tuner, demodulator and all re-quired memory in a single monolithic CMOS device that will enable design-ers to deliver today’s smallest, most power-efficient handset products.

Key features of the NMI320 solu-tion include up to 120 dB of variable gain, 50 dB of image rejection and greater than 55 dB of adjacent channel selectivity. The device consumes only 70 mW of power, yet still combines an extremely low 3.0 dB noise figure with a very high +20 dBm IP3. The monolithic chip includes a dual-band radio, an ISDB-T One-Seg and Three-Seg demodula-tor, plus all necessary memory in a very small footprint. No other external memory, baluns or loop filters are required to create a complete solution with a very low bill of materials.

The London-based market research firm Screen Digest reported in June 2007 that the Japan Electronics and Information Technology Industries As-sociation (JEITA) estimates that mobile TV handset shipments almost doubled during the first quarter of 2007 to a total of 7.3 million handsets, just under a year after first commercial deployment of the ISDB-T-based technology known as One-Seg. JEITA said that the strongest growth was recorded in March 2007, with more than 1.6 million shipments. One-Seg service is accessible without charge, and the associated handsets are available from all Japanese opera-tors.

Newport Media’s Sundance Series for DVB-H, mobile DVB-T and ISDB-T will also serve as the foundation for future solutions aimed at other popular air interface standards including, but not limited to, Terrestrial-Digital Multimedia Broadcasting (T-DMB) and MediaFLO. The Sundance J NMI320 is available in sample quantities and priced at $8.00 per unit in OEM quantities of 10,000. Volume production is scheduled to commence in Q407.

Newport Media Inc., Lake Forest, CA. (949) 340-6169. [www.newportmediainc.com].

TaNFilm Discrete Chips Meet Military S-Level Requirements

TT electronics IRC Advanced Film has further expanded its military product capabilities. In addition to offering a broad range of military-specific products including precision chips and resistor networks, IRC has received approvals for 16 DSCC drawings. IRC is one of the few manufacturers in the industry to offer TaNFilm discrete chips at S level (0.001% allowable failure) requirements.

IRC’s military-qualified products include MIL-Chip Series, PFC Military Series and TMC Military Series precision chip resistors; 1900 Series TaNFilm precision DIP resistor networks; 4700 Series TaNFilm precision SIP resistor networks; CCN Series TaNFilm preci-sion chip carrier resistor networks; FP Series TaNFilm precision flat pack resistor networks; and SON Series TaNFilm precision leadless resistor networks.

IRC meets the following military qualifications: MIL-PRF-55342; MIL-PRF-83401; MIL-PRF-83401/13 & 14; and MIL-PRF-83401–H. IRC’s approved DSCC drawings include: DSCC 87012; DSCC 87013; DSCC 87014; DSCC 87015; DSCC 87016; DSCC 87017; DSCC 87018; DSCC 87025; DSCC 87033; DSCC 87064; DSCC 88016; DSCC 88020; DSCC 94015; DSCC 94016; DSCC 01033; and DSCC 02010.

TT electronics IRC Advanced Film Division, Corpus Christi, TX. (361) 992-7900. [www.irctt.com].

AUGUST 2007 45

Page 46: Design Ideas: Serving Multicell Apps & Thermal

46 PORTABLE DESIGN

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Debug Tools for Infineon’s XC2300 MCU FamilyInfineon Technologies has unveiled its new scalable XC2300 microcon-

troller (MCU) family specifically designed for use in vehicle safety applica-tions. pls Programmierbare Logik & Systeme today announced—as the first manufacturer—a complete set of optimized debug tools specifically tailored to support the unique features of these 16/32 bit MCUs.

Both the UDE 2.0.12 and the UAD2 hardware from pls provide un-limited support for all internal debug resources and peripheral units of

Infineon’s new XC2300 MCUs. For example, depen-dent on the requirements of the application, different pins of the XC2300 devices can be configured as JTAG debug interfaces. The UDE 2.0.12 is usable with all conceivable combinations.

By use of a special mode, the connection between debugger and chip is retained even after a hardware reset. Furthermore, the integrated

Flash/OTP programming function of the UDE 2.0.12 provides exception-ally high speeds in the entire cycle: erase/download/program/verify. This support does not just apply for the on-chip flash, but also for external peripheral devices from: AMD, Atmel, Intel and other JEDEC-compatible flash memories.

JTAG, CANbus and serial interfaces are available to the user as a com-munication channel to the target. A special feature of the UDE 2.0.12 is its capability to support direct access to the MCU via bootstrap loader. In this mode of operation, the XC2300 MCU in the target system can be started under direct control of the debugger. This is particularly beneficial for initial start-up and subsequent service tasks, because it allows very fast and simple flash updates.

pls Development Tools, San Jose, CA. (408) 451-8408. [www.pls-mc.com].

Tricolor LED Driver for LCD Backlighting in Portable Devices

ON Semiconductor has introduced the NCP5623, a high-efficiency, triple-output LED driver with I²C interface and built-in grad-ual dimming. The device is specifically designed to drive tricolor RGB (red, green, blue) LEDs for fun lighting or enhanced LCD backlighting in portable applications such as cell phones and MP3 players. Offered in the compact LLGA-12 package, the NCP5623 is the smallest RGB LED charge pump driver housed in a non-bump plastic package on the market today.

The NCP5623 LED driver performs autonomous operations upon the command of the processor via its I²C interface. Its three independently controlled current outputs—with +/- 0.5 percent typical matching toler-ance and 32 current levels—allow the display of more than 32,000 colors with a tricolor RGB LED. The device features an integrated gradual dim-ming feature, which progressively increases or decreases output current to produce a theatrical fade-in/fade-out effect. The use of a logarithmic current profile ensures the light and color changes appear smooth and linear to human eyes.

To help maximize battery life, the NCP5623 achieves 94 percent peak efficiency with less than 1 micro ampere (µA) standby current over the operating range of a Lithium-based battery. Despite the small IC package, the device requires only four passive components to operate in a typical application. The device also features short-circuit and overvoltage protec-tion, which protects the system in case of LED failure.

The NCP5623 is housed in the lead-free (Pb-free) 2.0 mm x 2.0 mm x 0.55 mm LLGA-12 package and is priced at $0.55 per unit for 3,000 unit quantities.

ON Semiconductor, Phoenix, AZ. (602) 244-6600. [www.onsemi.com].

Dual Output Synchronous DC/DC Controller Draws only 30 μA in Automotive SystemsLinear Technology Corporation has introduced the LTC3826/-1, an ultra-low quiescent current,

2-phase dual output synchronous step-down DC/DC controller. The LTC3826/-1 draws only 30 µA when one output is active and only 50 µA when both outputs are active, making it ideal for automo-tive applications, such as navigation systems, where one or both supplies remain active while the engine is off. With both outputs shut down, the LTC3826/-1 draws a mere 4 µA.

The LTC3826/-1’s input supply range of 4V to 36V is wide enough both to protect against high input voltage transients and to continue operation during automotive cold crank. The LTC3826/-1 features a tight +/-1% reference voltage tolerance over the operating temperature range of -40°C to 85°C and can provide output voltages from 0.8V up to 10V, suitable for powering audio systems, analog tuners and CD/DVD players in automobiles. Each output can deliver up to 20A of current at efficiencies as high as 95%.

The LTC3826/-1’s constant frequency, current mode architecture provides excellent line and load regulation, and its 2-phase operation reduces input capacitance requirements. The LTC3826/-1 smoothly ramps each output voltage during start-up using separate adjustable soft-start and tracking pins. It operates at a selectable frequency between 250 kHz and 550 kHz, and can be synchronized to an external clock from 140 kHz to 650 kHz using its phased-locked loop (PLL). In addition, the user can select from Burst Mode Operation, pulse skipping and continuous operation at light loads. There are two versions offered: the LTC3826 is the fully featured part with additional functions that include a clock out, phase modulation, two separate power good signals and a current limit foldback disable capability.

The LTC3826 is offered in 32-lead 5 mm x 5 mm QFN package, whereas the LTC3826-1 is housed in the 28-pin SSOP. Pricing for both parts in 1,000-piece quantities starts at $5.38 each.

Linear Technology, Milpitas, CA. (408) 432-1900. [www.linear.com].

Page 47: Design Ideas: Serving Multicell Apps & Thermal

0402 Multi-Layer Ceramic CapacitorTaiyo Yuden (U.S.A.), Inc.

has announced the mass production availability of its new AMK105BJ475MV multi-layer ceramic capaci-tor (MLCC) for decoupling power-line circuits in high-performance ICs used in cell phones, digital still cameras and other battery-powered portable electronics.

The AMK105BJ is the first MLCC to achieve a capaci-tance rating of 4.7 µF in the 1.0 × 0.5 × 0.5 mm (EIA

0402) case size. The AMK105BJ allows designers to obtain the desired capacitance value from a single 0402-size device, where two 2.2 µF-rated 0402 capacitors were previously required. This saves cost and simplifies manufacturability by reducing parts count by 50 percent for this applica-tion. Moreover, the AMK105BJ allows designers to downsize from 0603-size components (1.6 × 0.8 × 0.8 mm) to the more compact 0402 size, resulting in space savings of 76 percent (volume) and 61 percent (area) without sacrificing device performance.

The AMK105BJ475MV (4.7µF, 0402) is available now for $0.15 each in OEM quantities.

Taiyo Yuden (U.S.A.), Inc., Schaumburg, IL. (847) 925-0888. [www.yuden.us].

Flexible 3.3V, 2.5V and 1.8V Clock Generator FamilyTexas Instruments (TI) has introduced a family of highly programmable, one to four phase-

lock loop (PLL) clock generator devices with the ability to generate up to nine output clock sources from a single input frequency. Each output can be programmed in-system for any clock frequency up to 230 MHz. These features provide a number of system benefits such as reduced power consumption, shorter lead time and the flexibility to easily upgrade the clock without redesigning the system. These benefits ultimately reduce cost for a broad range of consumer applications such as IP set-top boxes or phones, digital media systems such as digital televisions, streaming media and printers, navigation systems and portable devices.

The new CDCE9xx and CDCEL9xx family of clock generators ranges from one to four PLLs with very low jitter at 60 picoseconds typical. The CDCE9xx devices provide either 2.5V or 3.3V outputs, and the CDCEL9xx provide 1.8V outputs, enabling the low-power capability needed for portable devices. Each PLL supports spread-spectrum clocking (SSC) to reduce electromagnetic interference (EMI) to enable compliance with EMC regulations.

The family provides a variety of programmability options including the ability to program and customize the devices in-system through I²C and EEPROM. By offering footprint compat-ibility across the family, designers can adapt the system design easily without changing hardware, which reduces cost and enables the designer to sim-ply increase or decrease the number of clock outputs. The new family of devices further simplifies system design by replacing a number of components in the system including crystals, oscillators, buffers and PLLs.

The CDCE949 is available now in 24-pin TSSOP package for $2.20 in 1K lots. The remaining devices in the family will be available throughout 2007 in 20-pin, 16-pin and 14-pin TSSOP packages. In addition, evaluation modules (EVMs) to evaluate the performance of the family are available.

Texas Instruments Inc., Dallas, TX. (800) 336-5236. [www.ti.com].

Eval Kit for Freescale MPC5516iSYSTEM AG, a manufacturer of emulation and test tools for use in

the development of embedded applications, has introduced a new low-cost evaluation kit with everything needed to begin embedded develop-ment on the new PowerPC 5516 microcontroller from Freescale.

The ITMPC5516 package consists of a board populated with the Freescale MPC5516 CPU, JTAG and Nexus debug connectors, as well as two serial interfaces and an onboard integrated iSYSTEM debugger. It ships with a power supply, USB cable and winIDEA IDE/debugger software. The software runs unlimited for 90 days, after which it is limited to a 32 Kbyte download file. Upgrades to a complete unlimited version of winIDEA are available. A complete GNU C compiler for the PowerPC and sample applications are also included.

A simple jumper selects whether the onboard iSYSTEM USB-JTAG debug-ger is used or an external debug tool is connected via JTAG or the 38-pin mictor interface. The latter enables the user to have full on-chip Nexus trace access. A trace is the basis for professional testing and the detection of major defects and bugs. Program execution and time stamps are recorded and displayed by a trace debug system. Profiling and code coverage analysis are additional capabilities enabled by such a Nexus trace tool.

iSYSTEM USA, San Diego, CA. (858) 385-9100. [www.isystem.com].

AUGUST 2007 47

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Page 48: Design Ideas: Serving Multicell Apps & Thermal

Single-Cell Charger Serves Multicell ApplicationsPhilip Simpson and Robert Stimach, Maxim Integrated Products, Inc.

U1 of Figure 1 is a battery monitor and charge controller useful for charging and gas-gauging applications. Though the IC (DS2770) is normally restricted to single-cell applications, it can operate in multicell applications after you add a few extra components to the standard application circuit.

U3 is a linear regulator used to drop the battery-pack voltage to a value suitable for normal operation of the DS2770. Low supply current (<4.5 µA) and a high input-voltage range (>12V) enable this device (MAX1726) to be

used in lithium-battery packs containing at least three cells. The low cur-rent draw extends battery life.

Because the battery voltage in this application is too high, a divider (R7/R9) has been added to reduce the voltage level at U1’s voltage-measuring input. Resistor values should be high to maximize battery life, so the circuit requires a buffer (op amp U4) to preserve accuracy. The op amp shown (MAX4240) is chosen for its rail-to-rail input, large common-mode input-volt-age range and low supply cur-rent. For divider strings totaling 1 MΩ or less you can reduce costs by removing U4, but only at the expense of some accuracy and battery life.

Transistors Q3 and Q4 operate in the common-base configuration as level transla-tors. They have the full supply voltage across their collector-emitter junctions, but collector currents are low. Their current gain (Hfe) is not critical, so any suitably rated NPN signal tran-sistor is suitable. The choice of Q1 is governed mainly by the required charge current, so high gain and a suitable collector-current rating are the main considerations. For the less-critical Q2, a general-pur-pose PNP signal transistor is

48 PORTABLE DESIGN

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Untitled-3 1 8/6/07 9:45:07 AM

The Figure 1 circuit produces these charge-voltage profiles for the levels

of charging current shown.

figure 2

IMAX

=2.0A

IMAX

=1.5A

IMAX

=1A

Charge Current vs Voltage

2.5

2

1.5

1

0.5

0

5.5 6 6.5 7 7.5 8 8.5 9

Battery Voltage (V)

Bat

tery

Cha

rge

Cur

rent

(A)

The external circuitry shown enables this single-cell battery monitor and charge controller (U1) to charge multiple-cell batteries.

figure 1PACK+

CHARGE SOURCE

PACK-

Q1PNP

Q2PNP

NPNQ3

Q4

NPN

R6

360R

R3100R

R4100R

R11

R7

R10

U4

2M2U3MAX1726EUK5

BAT19V

C41uF

U2

PROTECTOR

C31uF

R92M2

MAX4240

R1150R

1K

1K

C2100nF

R5150R

C1

100nFR2

RES

DATA

U1 DS27701

2

3

4

5

6

7

8

UV

CC

VCH

SNS

SNS

SNS

N/C

IS2

Vdd

VIN

DQ

Vss

Vss

Vss

N/C

IS1

16

15

14

13

12

11

10

9

-

+

OUT IN

GN

D

GN

D

SH

DN

Page 49: Design Ideas: Serving Multicell Apps & Thermal

AUGUST 2007 49

algorithm solutions require specific firmware to control each unique print head. The arduous task of changing firmware adds an extra level of com-plexity, and therefore difficulty, to hardware changes.

But this need not be the case. A single programmable power manage-ment IC, such as Lattice Semiconductor’s POWR607, can provide multi-ple threshold comparators to monitor print head temperature. In addition, other power management functions for the handheld thermal printer can be integrated within the programmable device. A proposed block diagram for a handheld thermal printer is shown in Figure 1.

When the print head temperature exceeds its safe operating range, the power management device signals the microprocessor to reduce printing speed. When the operating temperature is back within a safe range, the power management IC signals the microprocessor to resume normal op-eration. The logic is performed entirely within the programmable device. Hardware changes, such as new print heads, require only simple repro-gramming of the voltage thresholds; complex firmware updates become a thing of the past.

Other power management functions in handheld thermal printers are often performed by a set of discrete components. The same power man-agement device used for thermal management can also perform all the key power management functions, from power up through normal opera-tion. The power management device not only replaces the ADC, but also the reset generator IC, voltage supervisor ICs, mechanical power switch and LED controllers.

While the system is starting up, the programmable device monitors the voltage of the power supplies and, through a simple logic equation and a programmed voltage threshold, sends the CPU reset signal to the microprocessor. Power supply voltages are continuously monitored while the printer operates. The power management device also features a power-down mode, where it draws 10 microamperes, making it ideal for power-sensitive handheld applications.

For less than the price of a single ADC, a power management IC such as the POWR607 can be implemented to handle all thermal and power management functions in a handheld thermal printer. This programmable solution reduces system cost and implements hardware changes with simple software updates.

Lattice Semiconductor, Hillsboro, OR. (503) 268-8000. [www.latticesemi.com].

acceptable. Maximum charging voltage depends on the charging current (Figure 2).

The ratio of R7 to R9 depends on the number of cells to be charged, and the sum of these resistor values should be as large as practical to reduce cell discharge. The circuit shown is suitable for charging two cells. For three cells, R7 should be twice the value of R9.

R2, the shunt for current measurement and gas gauging, should be selected according to the application. (Consult the DS2770 data sheet for more details.) Some variants of U1 include an internal shunt suit-able for this purpose. Note that BAT1 and U2, which protect the battery being charged against overvoltage, undervoltage, overcharge current and overdischarge current, are usually integral to that battery. Note also that satisfactory operation of this circuit depends on the use of an external-cur-rent limited supply with the correct output voltage.

Maxim Integrated Products, Inc., Sunnyvale, CA. (408) 737-7600. [www.maxim-ic.com].

Thermal Management for Handheld Thermal Printers – A Programmable Solution

by Brady McMacken, Marketing Engineer Lattice Semiconductor Corporation

Thermal management is critical to ensure high-quality printing from hand-held thermal printers. At the same time, the ever-increasing demand for smaller, lower-cost products with increased functionality presents daunting challenges for design engineers. Integrating thermal and power manage-ment ICs into a single-chip programmable solution allows design engineers to reduce overall system cost, complexity and board space and increase system reliability and performance.

Thermal print head temperature is proportional to printing speed. If the temperature is too hot, the ink will smudge. On the other hand, when the temperature is too cool the ink may become illegible. Consequently, a con-troller adjusts the printing speed to maintain the temperature within these two thresholds.

To facilitate low-cost design, thermal print head electronics provide an

analog voltage proportional to the print head’s temperature. Most control-lers use a microprocessor and an Analog to Digital Converter IC (ADC) to convert the voltage to a digital code. A software algorithm, implemented in the microprocessor, regularly compares the digital code to internally stored thresholds and adjusts the printer speed accordingly.

However, print heads from different vendors have different thresholds and therefore require different monitoring rates. ADC-based software

design idea

Handheld Thermal Printer Block Diagram

figure 1

ThermalPrint Head

Microprocessor

LED Control

SystemSupply

Temp_Mon

InputSupply

Voltag

eM

onitor

On/OffControl

Tem

p H

i/Lo

CPU

_Res

et

POWR607

Page 50: Design Ideas: Serving Multicell Apps & Thermal

advertiser index

50 PORTABLE DESIGN

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10/02-04/07ARM Developers’ Conference& Design Pavilions Santa Clara, CA www.rtcgroup.com/arm/2007

10/03-04/07Portable Design Conference & Exhibition (PDCE)Santa Clara, CAwww.portabledesignconference.com

10/11/07Real-Time & EmbeddedComputing ConferenceTyson’s Corner, VAwww.rtecc.com/tysons

If you wish to have your industry event listed, contact Sally Bixby with The RTC Group at [email protected]

Actel Corporation 51 www.actel.com

Amphenol Mobile Consumer Products/T&M Antennas 17 www.ampphenol-tm.com

ARM Developers Conference 41 www.arm.com

Atmel 27 www.atmel.com

Cirrus Logic 2, 16 www.cirrus.com

EDA Tech Forum 16 www.edatechforum.com

Embedded Systems Conference 13 www.embedded.com/esc/

Empower Technologies 30 www.empowertechnologies.com

Intersil Corporation 5, 7 www.intersil.com

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Maxim Integrated Products 9 www.maxim-ic.com

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National Semiconductor 52 www.national.com

Portable Design Conference 43 www.portabledesign.com

Semico Research 48 www.semico.com

Tesilica 24 www.tensilica.com

Page 51: Design Ideas: Serving Multicell Apps & Thermal

The 5 µW FPGA for cool portables.

Reduce power usage by a factor of 4, extend battery life by afactor of 5. Actel’s IGLOO FPGA family supports 1.2 V, with anincredible 5 μW static mode. The secret is Flash∗Freeze™ technology,which is simple to apply, maintains system status, and saves batterypower for when it’s needed.

It’s low power without limits. Actel IGLOO devices accelerate timeto market, and starting at $1.50 per unit, they won’t compromise yourbudget. With the help of Actel’s optimized Libero® Integrated DesignEnvironment (IDE), it leaves you free to build low power, highdensity, feature-rich solutions for the next generation of portablebattery powered devices.

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Page 52: Design Ideas: Serving Multicell Apps & Thermal

RGB LED Driver Generates Highly Effi cient “True White” Backlighting

Ideal for navigation systems, mobile phones, medical devices, and other portable devices

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

For FREE samples, datasheets, and more information on the LP5520, contact us today at: led.national.com

Or call: 1-800-272-9959

Typical Application Diagram

LP5520 Provides Innovative, Easy-to-Use, Instant Color Gamut Improvement for Small Format Displays

Product Description Packaging

LP5520 RGB Backlighting LED driver with integrated white balance compensation microSMD-25

LP5521 Programmable, low power, 3-channel LED driver microSMD-20, LLP-24

LP5522 Autonomous single LED controller with one wire interface microSMD-6

LP5526 Lighting Management Unit with high voltage boost converter with up to 150 mA serial fl ash LED driver microSMD-25

LP5527 LED driver for camera fl ash and 4 LEDs with I2C programmability, LED connectivity, test, and audio synchronization

microSMD-30

LP55281 13 channel LED driver with audio sync, LED connectivity test and independent PWMS/PWMS blinking cycles

microSMD-36

Key Features• Temperature compensated LED intensity and color

• Individual calibration coeffi cients for each color

• Color accuracy ΔX and ΔY ≤ 0.003

• 100% NTSC color gamut, brighter color, better picture quality

• User programmability for effects, aging, dimming

• PWM control inputs for each color

LP55XX

CalibrationMemory

SPI/I 2CInterface

BOOSTADC

LEDDrivers

MCUwithI2Cor

SPI

+

COUTC VDDA C VDDD C IN

2.9 - 5.5V 5 - 20V

FB

SW

ROUT

LP5520

VDDA VDDD

S1_IN

S2_IN

PWMRPWMGPWMB

VLDO

NRSTSS/SDA

SCK/SCLSI/A0SOIFSEL

CVDDIO

100 nF

VDDIO

C VLDO

BRCGND

LM 20VLDO

GOUT

BOUT

D1

-

Color and BrightnessPWM Logic

NEW!

NEW!

NEW!

NEW!

Untitled-3 1 7/17/07 11:01:02 AM