electron 'world...the ubiquitous ivor catt has a go at the emc fraternity 52 cell phones surge ahead...

.ectronics World's renowned news section starts on page 4

ELECTRON'WORLD 9_AAY 2004 £3.25

Cs709 8 33097

0 5>

in memoriam John Linsley Hood MIEE

FPGAsdemystifiedA new monitoringpool for 5.1 audio

?recision rectifierircuits

3 GSM:ongress report

SASSOCIATION

Circuit ideas: Jitter generator Low battery warning device

Blown fuse indicator

Te netENI 550L Amplifier (1.5 to 400MHz) 50 Watts £2500Hewlett Packard 3314A Function Generator 20MHz £750Hewlett Packard 3324A synth. function/sweep gen. (21MHz) £1950Hewlett Packard 3325B Synthesised Function Generator £2500Hewlett Packard 3326A Two -Channel Synthesiser £2500H.P. 4191A R/F Imp. Analyser (1GHz) £3995H.P. 4192A L.F. Imp. Analyser (13MHz) £4000Hewlett Packard 4193A Vector Impedance Meter (4-110MHz) £2900Hewlett Packard 4278A lkHz/1MHz Capacitance Meter £3500H.P. 53310A Mod. Domain Analyser (opt 1/31) £3950Hewlett Packard 8349B (2 - 20 GHz) Microwave Amplifier £2000Hewlett Packard 8508A (with 85081B plug-in)

Vector Voltmeter £2500Hewlett Packard 8904A Multifunction Synthesiser (opt 2+4) £1750Hewlett Packard 89440A Vector Signal Analyser (1.8GHz)opts AY8, AYA, AYB, AY7, IC2 £9950Agilent (HP) E4432B (opt 1E5/K03/H03) or (opt lEM/UK6/UN8)

Quality second -usertest & measurement Firequipment MEI

vow

(250kHz - 3GHz) £6000Marconi 6310 - Prog'ble Sweep gen. (2 to 20GHz) - new £2500Marconi 6311 Prog'ble sig. gen. (10MHz to 20GHz) £2995Marconi 6313 Prog'ble sig. gen. (10MHz to 26.5GHz) £3750R&S SMG (0.1-1GHz) Sig. Generator (opts B1+2) £2500Rhode & Schwarz UPA3 Audio Analyser 11500Rhode & Schwarz UPA3 Audio Analyser £2250Fluke 5800A Oscilloscope Calibrator £8995

OSCILLOSCOPES

Radio Communications Test SetsAgilent (HP) 8924C (opt 601) CDMA Mobile Station T/Set £8500Agilent (HP) E8285A CDMA Mobile Station T/Set £8500Anritsu MT8802A (opt 7) Radio Comms Analyser (300kHz-3GHz) £8500Hewlett Packard 8920B (opts 1,4,7,11,12) £6750Hewlett Packard 8922M + 83220E £2000Marconi 2955 / 2955A from £1250Marconi 2955B/60B £3500Marconi 2955R £1995Motorola R2600B £2500Racal 6103 (optsl, 2) £5000Rohde & Schwarz SMFP2 £1500Rohde & Schwarz CMD 57 (opts B1, 34, 6, 19, 42, 43, 61) £4995Rohde & Schwarz CMT 90 (2GHz) DECT £3995Rohde & Schwarz CMTA 94 (GSM) £4500Schlumberger Stabilock 4015 £3250Schlumberger Stabilock 4031 £2750Schlumberger Stabilock 4040 £1300Wavetek 4103 (GSM 900) Mobile phone tester £1500Wavetek 4032 Stabilock Comms Analyser £4000Wavetek 4105 PCS 1900 GSM Tester £1600

Agilent (HP) 54600B 100MHz 2 channel digital £800Agilent (HP) 54602B 150MHz 4(2+2) channnel digital £1250Agilent (HP) 54616B 500MHz 2 channel digital £1750Agilent (HP) 54616C 500MHz 2 channel colour £2750Agilent (HP) 54645D DSO/Logic Analyser 100MHz 2 channel £2750Hewlett Packard 54502A - 400MHz - 400 MS/s 2 channel £1600Hewlett Packard 54520A 500MHz 2ch £2750Hewlett Packard 54600A - 100MHz -2 channel £675Hewlett Packard 54810A 'Infinium' 500MHz 2ch £2995Lecroy 9310CM 400MHz - 2 channel £2250Lecroy 9314L 300MHz - 4 channels £2750Philips 3295A - 400MHz - Dual channel £1400Philips PM3392 - 200MHz - 200Ms/s - 4 channel £1750Philips PM3094 - 200MHz - 4 channel £1500Tektronix 2220 - 60MHz - Dual channel D.S.O £850Tektronix 2221 - 60MHz - Dual channel D.S.O £850Tektronix 2235 - 100MHz - Dual channel £500Tektronix 2245A - 100MHz - 4 channel £700Tektronix 2430/2430A - Digital storage - 150MHz from £1250Tektronix 2445 - 150MHZ - 4 channel +DMM £850Tektronix 2445/2445B - 150MHz - 4 channel £800Tektronix 2465/2465A /2465B - 300MHz/350MHz 4 channel from £1250Tektronix TDS 310 50MHz DSO - 2 channel £750Tektronix TDS 420 150 MHz 4 channel £950Tektronix TDS 520 - 500MHz Digital Oscilloscope £2500Tektronix TAS 475 100MHz - 4 channel analogue £750Tektronix TDS 340 100MHz - 2 channel digital £950Tektronix TDS 360 200MHz - 2 channel digital £1200Tektronix TDS 420A 200MHz - 4 channel digital £1800Tektronix TDS 540B 500MHz - 4 channel digital £2500Tektronix TDS 640A 500MHz - 4 channel digital £2700Tektronix TDS 744A 500MHZ - 4 channel digital £4250Tektronix TDS 754C 500MHz - 4 channel digital £4500

SPECTRUM ANALYSERSAdvantest 4131 (10kHz - 3.5GHz) £3000Agilent (HP) 35665A (opt. 1 D1) Dual ch. Dynamic Signal Analyser £3750Agilent (HP) 3588A High Performance spec. An. 10Hz - 150MHz £6250Agilent (HP) 8560A (opt 002 - Tracking Gen.) 50Hz -2.9GHz £5000Agilent (HP) 8593E (opt 41/105/130/151/160) 9kHz - 22GHz £12000Agilent (HP) 8594E (opt 41/101/105/130) 9kHz - 2.9GHz £4250Agilent (HP) 8753D Network Analyser (30kHz - 3GHz) £8500Agilent (HP) 8590A (opt H18) 10kHz - 1.8GHz £2500Agilent (HP) 8596E (opts 41/101/105/130) 9kHz - 12.8 GHz £8000Farnell SSA -1000A 9KHz-1 GHz Spec. An. £1250Hewlett Packard 3582A (0.02Hz - 25.5kHz) dual channel £1500Hewlett Packard 3585A 40 MHz Spec Analyser £3000Hewlett Packard 3585B 20 Hz - 40 MHz £4500Hewlett Packard 3561A Dynamic Signal Analyser £3500Hewlett Packard 8568A -100kHz - 1.5GHz Spectrum Analyser £3500Hewlett Packard 8590A (opt 01, 021, 040) 1MHz-1.5MHz £2500Hewlett Packard 8713C (opt 1 El) Network An. 3 GHz £6000Hewlett Packard 8713B 300kHz - 3GHz Network Analyser £5000Hewlett Packard 8752A - Network Analyser (1.3GHz) £4995Hewlett Packard 8753A (3000KHz - 3GHz) Network An. £3250Hewlett Packard 8753B+85046A Network An + S Param (3GHz) £6500Hewlett Packard 8756A/8757A Scaler Network Analyser from £900Hewlett Packard 8757C Scalar Network Analyser £3500Hewlett Packard 70001A/70900A/70906A/70902A/70205A - 26.5 GHz

Spectrum Analyser £7000Tektronix 492P (opt1,2,3) 50KHz - 21GHz £3500Tek 496 (9KHz-1.8GHz) £2500

All equipment is used - with 30 days guarantee and 90 days insome cases.Add carriage and VAT to all goods.

1 Stoney Court, Hotchkiss Way, Binley Industrial EstateCoventry CV3 2RL ENGLAND

MISCELLANEOUSAgilent (HP) 8656A / 8656B 100kHz-990MHz Synth. Sig. Gen.Agilent (HP) 8657A/ 8657B 100kHz-1040 or 2060MHzAgilent (HP) 8644A (opt 1) 252kHz - 1030 MHz Sig.Gen.Agilent (HP) 8664A (opt 1 + 4) High Pert. Sig. Gen. (0.1-3GHz)Agilent (HP) 8902A (opt 2) Measuring Rxr (150kHz-1300MHz)Agilent (HP) 8970B (opt 020) Noise Figure MeterAgilent (HP) EPM 441A (opt 2) single ch. Power MeterAgilent (HP) 6812A AC Power Source 750VAAgilent (HP) 60638 DC Electronic Load 250W (0-10A)Anritsu MG3670B Digital Modulation Sig. Gen. (300kHz-2250MHz)Anritsu/Wiltron 68347B (10MHz-20GHz) Synth. Sweep Sig. Gen.EIP 545 Microwave Frequency Counter (18GHz)EIP 548A and B 26.5GHz Frequency CounterEIP 575 Source Locking Freq.Counter (18GHz)EIP 585 Pulse Freq.Counter (18GHz)Fluke 6060A and B Signal Gen. 10kHz - 1050MHzGenrad 1657/1658/1693 LCR metersGigatronics 8541C Power Meter + 80350A Peak Power SensorGigatronics 8542C Dual Power Meter + 2 sensors 80401AHewlett Packard 339A Distortion measuring setHewlett Packard 436A power meter and sensor (various)Hewlett Packard 438A power meter - dual channelHewlett Packard 3335A - synthesiser (200Hz-81 MHz)Hewlett Packard 3784A - Digital Transmission AnalyserHewlett Packard 37900D - Signalling test setHewlett Packard 4274A LCR MeterHewlett Packard 4275A LCR MeterHewlett Packard 4276A LCZ Meter (100MHz-20KHz)Hewlett Packard 5342A Microwave Freq.Counter (18GHz)Hewlett Packard 5385A -1 GHz Frequency counterHewlett Packard 8350B - Sweep Generator MainframeHewlett Packard 8642A - high performance R/F synthesiser (0.1-1050MHz)Hewlett Packard 8901B - Modulation AnalyserHewlett Packard 8903A, B and E - Distortion AnalyserHewlett Packard 11729B/C Carrier Noise Test SetHewlett Packard 85024A High Frequency ProbeHewlett Packard 6032A Power Supply (0 -60V) -(0-50A)Hewlett Packard 5351 B Microwave Freq. Counter (26.5GHz)Hewlett Packard 5352B Microwave Freq. Counter (40GHz)IFR (Marconi) 2051 (opt 1) 10kHz-2.7GHz Sig. Gen.Keithley 220 Programmable Current SourceKeithley 228A Prog'ble Voltage/Current Source IEEE.Keithley 238 High Current - Source Measure UnitKeithley 486/487 Picoammeter (+volt.source)Keithley 617 Electrometer/sourceKeithley 8006 Component Test FixtureMarconi 6950/6960/6960A/6970A Power Meters & SensorsPhilips 5515 - TN - Colour TV pattern generatorPhilips PM 5193 - 50 MHz Function generatorRohde & Schwarz FAM (opts 2,6 and 8) Modulation AnalyserRohde & Schwarz NRV/NRVD Power meters with sensorsRohde & Schwarz AMIQ I/O Modulation Generator 2 channel

from £600from £1250

£4500£10500£7500£3950£1300£2950£1000£4250£9000£1000

from £1500£1200£1200£950

from £500£1250£1995£600

from £750£1750£1750£2950£2500£1750£2750£1400£850£495

£1500£2500£1750

from £1000from £2500

£1000£2000£2750£5250£5000£1750£1950£3750

£1350/£1850£1950£1750

from £400£1400£1350£2500

from £1000£3500

Rohde & Schwarz SMIQ 03B Vector Sig. Gen. 3.3GHz £7000Stanford Research DS360 Ultra Low Distortion Function gen. (200kHz) £1400Tektronix AM503 - AM503A - AM503B Current Amp's with M/F and probe from £800Tektronix AWG 2021 Arbitrary Waveform Gen. (10Hz-250MHz) 2 ch. £2400Wayne Kerr 3245 - Precision Inductance Analyser £1750Bias unit 3220 and 3225L Cal.Coil available if required. (P.O.A)Wayne Kerr 3260A + 3265A Precision Magnetics Analyser with Bias Unit £5500W&G PCM-4 PCM Channel measuring set £3750

Tel: 02476 650 702Fax: 02476 650 773Web: www.telnet.uk.comEmail: [email protected]

MAY 2004 VOLUME 110 NUMBER 1817

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COMMENTThe end of an era

NEWS Power fet uses nanotubes CMOS extends its reach Europe lags on R&D spending Wideband radar pinpoints objects Diamonds are harder, forever

FPGAS DEMYSTIFIEDAll you ever needed top know about

Programmable Gate Arrays, but were afraid toask. Eddie Insham dons his wizard's hat

IN MEMORIAMJ L LINSLEY HOOD MIEEOne of the best audio designers ever passed awaythis month. Ian Hickman reflects

A NEW MONITORINGTOOL FOR 5.1 AUDIOIn a slightly off -topic article, Richard Brice looks

at the eccentricities of monitoring multi -channelsound in a professional environment

LF

LFE

LS

CentreINN

RF

RS

26 PRECISION RECTIFIERCIRCUITSIntrigued by a recent Circuit Idea, Alan Bate hassome different ideas

32 A CURIOUS NEW RESULTIN SWITCHING THEORYLee Sallows reckons he's found a fundamentalnew result

....... ................ !

41 CIRCUIT IDEAS Jitter generator Up -Down -pushbutton control for digital

potentiometers Ultrasonic oscillator Low battery warning device Traffic light simulator Long delay timer using only one 555 chip Blown fuse indicator

48 NEW PRODUCTSThe month's top new products

50 NOT ME, GUVThe ubiquitous Ivor Catt has a go at the EMCfraternity

52 CELL PHONES SURGEAHEADIan Poole reports on this month's 3GSMCongress in Cannes

55 LETTERS Clangers Archiving 802.11 Cathode Ray and M. G. Scroggie Audible distortion The safe route

60 WEB DIRECTIONSUseful web addresses for electronics engineers

June issue on sale 6 Maya

May 2004 ELECTRONICS WORLD1

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41

a

EDITOR

Phil [email protected]

CONSULTANTIan Hickman

CONTRIBUTING EDITORMartin Eccles

PRODUCTION EDITOR/DESIGNERJane [email protected]

EDITORIAL E -MAILS

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GROUP SALES

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Tel (0) 1353 654431Fax (0) 1353 654400DisclaimerWe work hard to ensure that the informationpresented in Electronics World is accurate.However, Electronics World's publisher -Highbury Business - will not take responsibilityfor any injury or loss of earnings that may resultfrom applying information presented in themagazine. It is your responsibility to familiariseyourself with the laws relating to dealing withyour customers and suppliers, and with safetypractices relating to working withelectrical/electronic circuitry - particularly asregards electric shock, fire hazards andexplosions.

The end of an eraAs I'm sure you read onthe cover, one ofour great audiocircuit designerspassed away thismonth.Elsewhere in thisissue, IanHickman haspenned an obituary,so I won't go on toomuch.

John LinsleyHood's name firstcame to my attentionwhen I joined the BBC -in 1970. The 1969 Class I,A design was rapidlygaining a 'cult'following. Almosteverybody in Londonstudio engineering had acouple of channels going,and I even put a pair inmy car! I built them frombits in the junk box and aset of PCBs that a bloke onthe other shift was sellingthrough WW. In fact, headvertised his extensionnumber in the ad - and gotpeople on the other shift totake messages when hewas not there! A bit ofbrazen profiteering.

Completelycoincidentally, nextmonth we start a seriesof audio articles fromGraham Maynard,who pulls heavily onJLH's early work.The Class A design isreferenced more thanonce, so I think it isappropriate toreprint the original ClassA article as a tribute to the great man.

So, if anybody has any comments,recollections or just plain tributes to pay,

Oetimein electronics

please send them in, asnext month we will berunning a propermemorial to him, When Isay next month, I meanas soon as you read this- get them over as weonly start the next issuea few days after youare reading this. As weonly got the news afew days before goingto press, I've not beenable to do much thismonth, but oursympathies go outto his wife, Junewho kindlyphoned us withthe sad news.

On a differentnote, I've been

..antleri

a life titn ,e electrook

,

the authors -please keep itdown a bit toensure publication.

And I don't carewho started it, butsuffice to say that Iwill be handing out

detentions!

nns ,

noticing thatsome of the spats

in theletterssectionhave beengetting far

toopersonal. It

is for thisreason that

I've pulledsome recently.

1 So if you werefollowing a juicythread, apologies.If you are one of

Phil Reed

Electronics World is published monthly byHighbury Business, Media House,Azalea Drive, Swanley,Kent, 8R8 8HU

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May 2004 ELECTRONICS WORLD 3

Researchers at Infineon havemade a power semiconductorstructure using carbonnanotubes.

"This is considered abreakthrough fornanotechnology," said the firm,"since scientists previouslyassumed that these atomic -sizedcomponents were not suitable forthe high voltages and currentsused in power applications."

Making the mosfets is notcomplicated. "All processparameters, such as temperatureand materials, are suitable foruse in conjunction with standardsemiconductor manufacturingprocesses," said Infineon.

The firm first coated a metallicsubstrate with a thin insulatingoxide layer, then grew randomnanotubes on that bydecomposing a carbon -containing gas mixture.

A random tangle of nanotubesis deposited, much like a plate ofspaghetti, or the fibres in felt. Inthe mix are multi and single -walled tubes, conducting andsemi -conducting tubes, andvarious length tubes.

Drain and source electrodes arethen deposited directly onto thenanotube layer using a singlelithographic step - leaving asquare drain surrounded by asource, with a 90nm gapbetween them.

Although many do not,hundreds of the tubes have oneend in contact with the drain, andthe other in contact with thesource.

By applying a brief current

':DATE

Power fet uses nanotubes Magneticssoundattractive

pulse, conducting -type tubes arevaporised, leaving around 300desirable semiconducting tubes.

These are a mixture of high-performance single -walled andpoor multi -walled tubes, but nopractical separation techniquesyet exists to cut out the multi -walled tubes.

Potential on the substrate,which acts as a gate, pullscarriers into the semiconductingnanotubes and turns the deviceOn.

Current capability severalmicroamps per tube, and about2mA per structure. A viabletransistor could be built byparalleling thousands ofstructures. Maximum voltage is2.5V, limited by the 90nm gap.

The device is not practical forproduction, said the company.For future use, ways will have tobe found to grow mostly single -wall tubes, and grow them withspecific orientation.

If this can be achieved, thesimple production method couldmake nanotube power fetscommercially viable, saidInfineon, and there would beother advantages: "The mainadvantages offered by the newtype of power transistor can beseen in the significantly simplermanufacturing process, higherswitching speeds, reduced heatdevelopment and in the highcurrent densities that the tightlypacked carbon tubes are able towithstand."

A firm from Bristol isdeveloping magnetic particlesfor data storage that are formedand contained within proteins.

NanoMagnetics has wonseveral million pounds infunding to develop itstechnology, which coulddramatically increase datastorage density.

"Our technology is unique. Itallows consumer electronicsmanufacturers to integrate aDVD capacity, rewritable,removable storage product in aform factor no larger than amatchbook at a lower cost thanany other technology includingflash and magnetic tape," saidDr Eric Mayes, chief executiveat NanoMagnetics.

The basic technology isdubbed DataInk. It starts withhollow protein spheres with aninternal diameter of just eightnanometres inside which aregrown the magnetic particles.

The resulting powder can bemixed with resin and used tocoat surfaces of disk drives. Theuniform nature of the particlesmeans they can be laid downwith an even distribution.

"We are receiving a great dealof interest from a range ofindustries that are increasinglyreliant on data storage and havea need to increase storagecapacity," said Mayes.

DataInk could also be used asthe storage medium in magneticRAM chips, claimed Mayes.

World's smallest globeNTT, the Japanese telecomcarrier, has built an electronbeam lithography system thatcan create three-dimensionalstructures. To test its systemNTT etched the globe pictured.

The small sphere measures60/rm in diameter, with thesmallest patterned feature just 10nanometres wide.

To pattern 3D structures, NTTinvented a two -axis rotationsystem to move the sample. Aheight sensor made from aconfocal laser microscope isused the keep the e -beamfocused on the sample.

The resolution of the beam isclaimed to be 100 times betterthat optical or X-ray systems.

4 ELECTRONICS WORLD May 2004

CMOS extends its reachCMOS, that workhorse processof the chipmaking industry, isextending its influence furtherinto the wirelesscommunications sector.

Two companies, SiliconLaboratories and AxiomMicrodevices, have unveiledpower amplifiers for mobilephones made entirely in CMOS,while SiGe Semiconductor haspower amplifiers made usingsilicon germanium.

The beauty of using siliconCMOS or SiGe for the powerstage of RF equipment is thatcontrol circuitry can beintegrated alongside the

From left to right are the crystal, baseband processor, filter and6.4x3.9mm power amplifier for a Silicon Labs GSM handset.

amplifiers. This savescomponent count, cost, powerand improves reliability.

All three companies say theirpower amplifiers require noexternal components, unlike PAs

made using gallium arsenide(GaAs) or indium galliumphosphide (InGaP).

Silicon Labs and Axiom havedevices for the GSM mobilephone market. This brings huge

design challenges, as the highpower demand in GSM, up to33dBm antenna power, results inhigh voltages (up to 12V) in thePA when driving a 50 Ohm load.CMOS, with its low breakdownvoltage, cannot cope with this,so both firms have done someclever design.

Silicon Labs said it has anarchitecture that "distributes thehigh voltage across multipletransistors".

SiGe's device is aimed atwideband-CMDA (3G) phones.At 3x3mm the device is smallerthan the GSM devices, but 3Ghas lower power specifications.

Brain on a chipCanadian and German scientistshave taken a significant step ininterfacing brain cells to siliconchips.

Dr Naweed Syed from theUniversity of Calgary's Facultyof Medicine planted neurons on achip's surface and observedsynaptic connections operate asstimuli were applied.

"The nerve cells not onlyregenerate their synapticconnections on the silicon chipbut also exhibit memory tracesthat were successfully read by thechip," said Syed. Working withthe Max Planck Institute forBiochemistry in Munich, Syedcultured nerve cells from a snailbefore placing them on the chip.A stimulus applied to one cellwas communicated to others andread through a transistor on thedevice.

"We discovered that when weused the chip to stimulate theneurons, their synaptic strengthwas enhanced. This finding tellsus that these neurons areexhibiting signs of learning andmemory," said Syed.

The next stage is to connecthuman brain neurons to silicon.The Calgary team hope the workwill one day lead to control ofprosthetic limbs or even therestoration of sight.

UK firm marks 20 years in spaceUK satellite developer SSTL hascelebrated 20 years of successfulorbital operations, with itssecond satellite, UoSAT-2, stillin use today.

Thousands of radio amateurs,schools, college and universitygroups have received, decodedand analysed data transmitted byUoSAT-2. As well as the digitaltelemetry and whole -orbit datacollection files, plain text newsbulletins were uploaded to thesatellite each week andbroadcast around the world.

Schools were also able tolisten to digital voice encodedtelemetry data transmitted by thesatellite direct to two millionhandheld receivers. All of thisculminated in UoSAT-2supporting a trans -polar trek

transmitting the expedition'sposition using the voicesynthesiser.

Signals are still audible on the2 -metre amateur radio band(145.826MHz) and also, but notso strongly, on the2401.1428MHz S -band beacon.

UoSAT-2 was launched onMarch 1, 1984 onboard anAmerican Delta rocket from theWestern Range, Vandenberg AirForce Base in California.

Since then the firm has builtmore than 20 satellites, rangingin weight from six to 315kg.

The firm is currently buildinga 400kg device for ESA, the firstin the Galileo constellation ofpositioning satellites. It is alsoSSTL's first foray beyond lowEarth orbit.

Europe lags on R&D spendingEuropean countries spend twoper cent of GDP on researchand development in science andtechnology, but this lags boththe US and Japan, which spendalmost 3%.

Latest figures from theEuropean Union's statisticsservice show that the 15European states spend 1.99% on

R&D. Japan spends 2.98%,the US 2.8%.

Spending various from onecountry to another in the EU.Sweden exceeds 4%,Finland is at 3.5%.The UK spends around 1.84%on R&D.

In terms of absolute values,Germany is the big spender

with 052bn. France spendsaround a33bn, the UK justover 030bn.

In total the EU15 spend0176bn, compared to0315bn for the US and 0154bnfor Japan.

The EU has set a target ofspending 3% of GDP on R&Dby the year 2010.

May 2004 ELECTRON ICS WORLD

Proton polymerbattery nearsreleaseNEC Tokin has further developedits proton polymer batterytechnology, but still has not put itinto production.

First revealed in March 2000,proton polymer batteries can bethought of as half -way betweenbatteries and supercapacitors incapacity, cycle life and dischargecapability. In operation, protons(hydrogen ions) shuttle back andforth between two conductivepolymer electrodes as the cells ischarged and discharged by anoxidation-reduction reaction.

The protons are tiny comparedwith the ions normally exchangedbetween battery electrodes andtherefore cause almost no life -limiting electrode damage. "Acharging -discharging cycle of about100,000 times can be achieved,"said NEC, "surpassing the servicelife of general electronic systems. Itis expected that this battery will beused as an embedded power sourcethat needs no replacement."

The nimbleness of a proton alsomeans high -current charge anddischarge is possible. "About 20times that of a lead battery," saidthe firm. "Actually, a protonpolymer battery can be fullycharged in minutes, and even a200mAh cell is able to apply acurrent of as much as 10A. Thischaracteristic is closer to acapacitor than a battery."

Any voltage less than a protonpolymer cell's rated voltage can beapplied indefinitely withoutdamage, and complete discharge isharmless, NEC spokesman ShuHattori told Electronics World.

Capacity is about a tenth of alithium ion secondary battery,almost as much as a lead -acidbattery, and dozens of times morethan a super capacitor. At -20°C,70% of room temperature capacityis maintained.

NEC's reluctance to produceproton polymer cells could be fromlack of a clear market. Thetechnology was first developed formemory back-up in phones andPDAs, but these devices are gettingon fine without proton polymer.Now the company is emphasisingthe excellent environmentalcredentials of its new cells and isproducing prototypes in varioussizes, possibly in the hope that apotential customer will arrive withan application.

UK batteries go to MarsThe UK's AEA Battery Systemshas revealed that its lithium -ionbatteries are running theEuropean Space Agency's MarsExpress orbiter.

Although it makes its owncells, for military use, the actualcells on Mars Express are madeby Sony under AEA patents,then tested and matched by AEAfor space use.

By specifying a larger batterythan would be used in, say, a

computer with similar powerdemands, depth of discharge islimited and battery life extendedto the thousands of cyclesneeded in an orbiting solar -powered space craft.

Even with generous capacityspecification, the Li -ion cells areless than half the size, andlighter, than space -rated NiCdcells.

AEA also provided cells forill-fated Beagle2.

Mitsubishi Electric hasdeveloped a liquid crystaldisplay capable of showingimages on both its front andrear surfaces.The reversible LCD moduleconsists of a single liquidcrystal panel sandwichedbetween two transparentbacklights, each of which canbe turned on or off.The display is aimed at devicessuch as 'clamshell' mobilephones, which have asecondary display on showwhen the phone is closed.

Intel has developed an opticaltransceiver containing a lasertuneable across the entire C -band,

used by telecoms carriers fordense wavelength divisionmultiplexing. The C -band contains80 channels, each spaced by50GHz. By thermally tuning thelaser to any of these channels firmscan save money on inventory. TheIntel transceiver is able to support10Gbit/s transmissions.

World radio from UK firmA UK firm has developed aradio that picks up worldwidestations broadcast over theInternet.

Reciva's Internet radio useswireless LAN to connect to abroadband link, such as anADSL modem, without the needfor a PC.

"Our first radio product isdemonstrable now and allowslisteners to choose

radio stations from around theworld," said Trevor Goldberg,Reciva's chief executive.

"By eliminating the need for aPC, we bring listeningenjoyment to where it belongs;the kitchen and living room,rather than the home office andit's incredibly easy to use."

Goldberg said the firm plans tomanufacture products, to

license the technologyto third parties,

and alsoprovide anOEM basedoffering forcompanieswanting to

embed thetechnology.


Wideband radar pinpoints objectsCambridge Consultants Ltd(CCL) has developed a prototypeultra -wide band (UWB) radarsensor that can pinpoint objectsto within lm range and fivedegrees angular accuracy, andthen track them. Total range isaround 100m.

Applications in traffic areplanned: "For example, apedestrian crossing such as theUK's Puffin system might useDoppler radar to senseapproaching vehicles, inductionloops in the road to detectstationary traffic, and infrared tosense pedestrians," said thecompany. "CCL's ultra -wideband radar provides all thisinformation in one module,providing a complete image ofactivity with presence, directionand speed data on objects in itsfield of view."

The radar operates in the5.8GHz licence -free band.

It has a single transmit antennasurrounded by four receiveantennas. The whole assembly isabout 100mm across.

The central antenna transmitsan ultra -fast pulse, band -limited

to keep it legal. Four samplingreceivers detect returns, with theirsample delay varied so eachdetects objects in a hemisphericalsub -lm range 'slice' on eachtransmit pulse. In this way, theentire range is swept slice by slicemany times per second.

Digital signal processinganalyses the four receiver outputsand extracts a 3-D map of objects.

No exotic integrated circuitsare used, so production costsneed not be high and completesystems could be installed withlimited road digging. "UWBradar sensing provides vehicleand pedestrian detection that ismore effective for bothauthorities and road -users, andlower in cost," said JonGarnsworthy, head of transportsystems at CCL.www.cambridgeconsultants.com

Detector measures single photonsA detector forsingle photonshas beendeveloped atthe Universityof Oxford,which is nowlooking forpartners tocommercialisethe device.

"It is asingle photondetector withimprovedsensitivitycompared with scintillationcounters and any otherdispersive photon detector weknow of," said Dr Roger Welchof Isis Innovations, theuniversity's intellectual propertyexploitation arm.

Called Quatratran, for quasi -particle trapping transistor, it isa superconducting device whichproduces 10 to 20 electrons forevery photon hitting its topsurface. "It gives you energyresolution as well as detection,"said Welch. "It has applicationsin infrared and X-rayastronomy, materialscharacterisation, andflorescence measurements ofbiological samples."

In operation, said Welch, aphoton hits the top materialfreeing an electron -hole pair.

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where, relative to the localFermi level, the electron hasa lot of energy and freesbetween 10 to 20 electrons -depending on its energy.

These naturally drift intothe adjacent normal metaltrap layer where a biasvoltage causes them totunnel through a finalinsulator into a secondsuperconducting layer fromwhere they can be extracted.

Harvard Universitycontributed to thedevelopment, which is

continuing at the University ofNaples and Oxford.

www.isis-innovation.com

Diamonds areharder, forever

This is a synthetic brilliant cutsingle -crystal diamond grown bychemical vapour deposition. It isaround 2.5mm high and wasgrown in about one day atCarnegie. The seed crystal isyellow, hence the tint, which isdue to internal reflection as theCVD diamond is transparent.

Scientists at the CarnegieInstitution have used a standardchip making process to growsynthetic diamonds that are atleast 50% harder than naturalcrystals.

"These are real diamondsmade of carbon and identical instructure to those formed innature and by high pressure andtemperature methods," saidChih-shiue Yan from Carnegie.

The US team used chemicalvapour deposition (CVD) togrow diamonds on a seed crystalfrom a mixture of hydrogen andmethane. A high temperature(2000°C), high pressure (7GPa)process than 'hardens' thecrystals.

"Not only were the diamondsso hard that they broke themeasuring equipment, we wereable to grow gem -sized crystalsin about a day," added Yan.

His team have growndiamonds up to 10mm indiameter and 4.5mm thick.

No fan needed for 1GHz x86Taiwanese PC component makerVIA Technologies has producedfanless versions of its 800MHzand 1GHz x86 -compatible Edenprocessor.

Called ESP8000 andESP10000, the chips include thefirm's Nehemiah CPU core andthe 10000 dissipates 7Wmaximum at 1GHz.

"The processors are alreadybeing designed into computingand communications devices,including thin clients, personalservers and industrial PCplatforms," said VIA.

Included is the firm's second -

generation PadLock securitysystem with hardware AESencryption and two randomnumber generators. "Thisproduces encryption rates of12.5Gbit/s with minimal load onthe processor," said the firmnatively.

Multimedia capabilities come inthe form of VIA's matchedCLE266 chipset, which has ahardware MPEG-2 decoder,DDR266 SDRAM support, 6 -channel surround sound, USB2.0ports, and 10/100Mbit/s Ethernet.

VIA's previous processors haveappeared on its own -brand

miniature motherboards and,although no announcement hasbeen made, the new 800MHz and1GHz devices are expected tofollow suit. www.via.com.tw

Eden specification:

x86 compatible up to 1GHz operation 7W max power sixteen pipeline stages SSE multimedia instructions floating point unit 64kbyte L2 cache 35x12mm35x1.5mm BGA

package


Models are hot topics

Electronic engineering professionals can nowthermally model products at the earliest designstages through a software package fromSurrey -based Flomerics.

Priced at $7,900/seat/year, FLO/PCB as it iscalled, allows multiple physical and thermaldesigns to be evaluated without a specialist on -hand.

"The problem [bottleneck] is the rate atwhich a thermal expert can respond," saidRobin Bornoff, Flomerics' PCB productmanager. "FLO/PCB automates much of thenumerical aspect of analysis with defaultsettings covering 80% of applications. Thesecan be overridden for the remaining 20%."

Flomerics canvassed engineers, looking for asimple way to gather data for thermal analysis.It found that engineers like to draw functionalblock diagrams, ideal for FLO/PCB, buthave no standard way of doing it.

So Flomerics included an easy -to -usefunctional block diagram drawing tool inFLO/PCB which captures data for thermalanalysis as users draw their diagrams.

Users can add power dissipation figures invarious ways, from a simple globalpower/unit area figure for the whole physicalstructure, through dissipative rectangularblocks representing components, to fulldevice models from the included library.

Models for single and multiple boardarrangements include cards with mezzanineand daughterboards of arbitrary size andspacing are provided. Forced air and naturalconvective cooling are catered for.

Modeling is in 3-D. Options are 'trend', aquick coarse -grained evaluation forcomparing different options, and 'accurate'which is slower, but produces representativetemperatures. Functional block, physicallayout, and thermal views are availablesimultaneously on -screen.

Resultant physical layouts can be exportedto the company's full-blown computational

fluid dynamics package Flowtherm, and otherdesign tools. Thermal feasibility reports can begenerated automatically.

In future, an option to export the functionalblock diagrams to common schematic capturepackages may be added.

Customers buying multiple copies ofFLO/PCB, or buying bundles can expect pricereductions. A full release is due in April.

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Electricity is a flush away

Flushing the toiletcould lead to electricitygeneration, if work atPenn state Universitysees the light of day.

Environmentalengineers at theUniversity have shownthat a microbial fuelcell can generateelectricity fromstandard sewage andwaste water.

Bruce Logan andlead researcher,

Microbial fuel cells Hong Liu.work through the action ofbacteria that can pass electronsto an anode. Electrons arepassed to the cathode - acarbon/platinum catalyst/protonexchange membrane - where theelectrons combine withhydrogen ions (protons) andoxygen to form water.

Experiments have yielded upto 50mW of power per squaremetre of electrode surface. Theoxidising nature of the process

removes most of theoxygen demand fromthe organic matter inthe waste.

"If power generationin these systems can beincreased, MFCtechnology mayprovide a new methodto offset wastewatertreatment plantoperating costs, makingadvanced wastewatertreatment more

affordable for both developingand industrialised nations," saidBruce Logan, professor ofenvironmental engineering anddirector of the project.

Unlike some other microbialfuel cells, Logan's needs noextra bacteria or enzymes tobegin the process.

The cell is a 150mm tube,around 60mm in diameter,containing eight anodes giving atotal of 225cm2 of surface area.

Superconducting processorJapanese researchers havedesigned and built amicroprocessor fromsuperconducting Josephsonjunctions.

Over 5,000 junctions madefrom niobium are used in theCORE1 design, whichimplements a complete 8 -bitprocessor.

The team from NagoyaUniversity, and YokohamaUniversity and Japan'snational superconductingresearch centre said the designhas a clock speed of 15.2GHzand consumes a mere 1.6mWof power.

Low power is achieved bytransferring data with veryshort pulse widths, just a fewpicoseconds, and withvoltages under lmV. Theactual data transfermechanism is the single fluxquantum (SFQ), a well -testedtechnique.

Circuits using SFQs processdata by observing the pulseshape when single quanta passthrough a superconductingring containing the Josephsonjunctions.

CORE1 has a 32 -bytememory shared betweeninstructions and data, a 5 -bitprogram counter, 8 -bitinstruction register and twodata registers. The instructionset is very simple; halt, add,load, store, skip if zero, jumpand move.

To reduce complexity andcut the number of data lines,the arithmetic and logic unit isbit serial in form. This helps,as the clock signal'swavelength is significantcompared to the die size of theprocessor.

The processor measures1.8x2.8mm and because it issuperconducting it runs at atemperature of just 4.2K.


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116

FPGAsdemystifiedStarting on any new technology can be a difficult process if the first fewsteps are not very clear. A typical case is getting to knowProgrammable Gate Arrays. Eddie Insam explains some of the facts,and describes a step by step guide on getting started and building yourown simple programming development kit

Aweek hardly passes by withoutus being bombarded withinformation on new products,

new techniques and new devices.Adverts and press releases arepeppered with words such as`solutions' and 'benefits' that to me atleast, don't convey much information.Perhaps this is because I cannot seethe problem they are addressing in thefirst place. The press releasesthemselves don't help much by notmentioning it either! This kind ofsituation can be very confusing to anewcomer or to a recent graduate.The basic chicken and egg dilemma isthat if we know little or nothing abouta concept, it is unlikely that we willgain much information from materialpresented about it in an abstract way.We won't understand what they aretrying to say, or appreciate theirbenefits.

One such area is Gate ArrayTechnology (GA), also known undervarious other names such as PLDsand FPGAs. This is a typical exampleof a line of products that live in ajargon fenced world, and which canput a dead stop in anybody's learningcurve. The main barriers are a lack ofappreciation of the uses they can beput to, a perceived high cost of entryand the difficulty in knowing whereto start. Unless you are lucky or richenough to attend a course or seminar,the only practical way to enter thissecret world is by reading existingliterature. Unfortunately, a lot of theinformation available seems toassume you know all about thesubject and have a lab full ofequipment and software tools, most

of which having a purpose in life thatappears to be completely unknown.No wonder many designers who havenot been brought up on the subjectfrom college days are avoiding orrefusing to get involved in this magicworld.

This article will dispel some of themyths. Even if you are not interestedin using GAs, the article will inducesome confidence by introducingsome of the jargon. For those wishingto become more involved, there willbe a step by step guide, including aneasy to build circuit for aCPLD/FPGA device programmerthat won't cost a fortune. This,together with the free tools availablefor download from the internet, willmake the inroad into GA know-howaccessible to anyone.

Where would I use a gate array?Traditionally, GAs are used as directreplacement for glue logic. This isthe term given to the various logic

gates, counters and flip-flops that aredispersed around a PCB to providegeneral interfacing, buffering andaddress decoding. Their advantage,from a commercial point of view, isthat GAs are cheaper and occupy lessboard space than the discrete ICsthey replace. In order to make GAswork, they need to be programmed(not unlike a PROM). The fact thatthey can be fuse -programmed inplace means designs can be tweakedand modified after the PCB has beencommitted to production.

As GAs became more powerful,they started to be used as sub -modules or as complete designs intheir own right. For example, aspurpose built interfaces tomicrocontrollers, as fast UARTs oras complex communicationscontrollers for Ethernet or encryptionsystems. The latest generation ofGAs are powerful enough to includetheir own built in CPU cores, whichcan be used for standard computing

Not real electronics?

Gate Arrays? Surely they are not 'real' electronics, where is the fun in that?If you are one of those people who think projects involving GAs are notfor you because they are not 'true hardware' and would prefer to designprojects using discrete CMOS or TTL logic, this article is definitely for you.If it is because you are afraid to get into the technology, even more so.You do not know what you are missing! Even if you are a firm believer inthe old ways, there is good information here to allow you to understand abit on how they work, the jargon they use and what they could do for you.

Admittedly, any new technology takes away established methods thatwe may feel confident with. Gate Arrays do not take the fun out ofelectronics; they just place on a different level. There is an odd sense ofachievement when you try, modify and improve a logic design onsoftware before you commit to a PCB or even pick up a soldering iron.Welcome to the new order!

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'I VI- 11111or for specialist applications such asDigital Signal Processing (DSP).Developing your own CPU maysound a bit like re -inventing thewheel, but there are major advantagesin adding your own custominstructions to an otherwise standardset. For example, complexprocedures that require several 'C'language statements in a standardCPU could be performed within asingle clock cycle in a customisedset. This can result in a seriousincrease in performance, animportant factor in fast applicationssuch as voice or videocommunications.

The basicsLike any good old engineeringtextbook, we shall start at thebeginning. Programmable logicarrays have been with us for quite afew years. The original concept wasfirst conceived in the early days ofcustom integrated circuit design. Afew thoughtful manufacturersdecided to offer IC 'pizza bases'consisting of gates, flip flops andother components laid out in neatsubstrate arrays but without the finalmetalisation layer topping (that is, thewiring connection between thedevices). Users only needed to plan adesign for this final layer and submita CAD file containing the nodeinterconnections to the manufacturerfor final phase production. The usersdid not need to get involved in thedesign of the IC gates, nor they didneed to know how they worked apartfrom knowing there were so manyflip-flops, gates or whatever per chip.

Some of you may remember thevenerable 82S32 fusible link PROM(still available today amazinglyenough!) This was nothing more thana 32x8 cross array of open collectortransistors forming a 256 bit memorycell in a standard dual in linepackage. The device was`programmed' by applying highvoltages to some of the pins, whichmade the internal die cross links`blow up' ending up with theequivalent of a one timeprogrammable 32 byte ROM. Thedevice could operate at nanosecondswitching speeds, very fast in thosedays, making it useful in applicationssuch as address decoders anddynamic ram timing generators.

The next evolutionary step sawgates and flip-flops being integratedas building blocks within theinterconnected fuse arrays. Thesedevices have the generic name ofProgrammable Logic (PLD), orProgram or Gate Array Logic (PALor GAL). A typical design has aquantity of islands or blocks ofstandard flip-flops layouts withprogrammable feedback paths andprogrammable random logic inputs(Figure 1) A typical device may have8, 10 or more of these macrocellswithin a dual in line package. Theinputs to the flip-flops are fed from amatrix array of combinatorial inputs,so that various Boolean logiccombinations can be programmed todrive the register's D inputs, eitherfrom the outside world, or from otherflip-flops within the package. Thismakes PLDs useful as simple addressdecoders, adders, counters, shift

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A typical PLD consists of a number of macrocells linked to acommon cross -wire bus (A). The connections are defined byfuse links that are programmed to be either on or off thusestablishing the final operation of the device. Each macrocellconsists of a standard circuit using a D flip-flop and a numberof combinatorial AND -OR logic inputs (B).

registers, timers, parity generatorsetc. A separate clock pin usuallydrives all the flip-flops within thechip, and most devices includeseparate pins for clear, preset and tri-state output enables. Typical partnumbers have names like 16V8,20L8, 22V10 etc, where the first twodigits indicate the number of logicinput pins, the last digit the numberof flip-flops, and the middle letter orletters, the technology used; withsome minor variation amongmanufacturers. Each of these devicesis designed to replace 4-5 equivalentCMOS or TTL packages. Not aworld shattering improvement, butuseful in context as PCBs get moreand more crowded.

Most of the newer PLD familiesuse CMOS technology, whilst the


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older use established MOStechniques mainly devised to achievefast switching speeds, withpropagation delays of 5nS or less.One hidden aspect of this technologyis that static power dissipation can bequite high; a factor to consider whencalculating overall board costs. Fromthe programming point of view,devices are either one-timeprogrammable (in -site or at thefactory) or re -programmable by theuse of electrically erasable memorycells. Depending on technology,special voltages and pulse patternsmay be required, and asprogramming information is notalways openly or freely availablefrom manufacturers, specialcommercial programmers may needto be obtained.

Programming information takes theform of fuse co-ordinate listings.These are collections of ones andzeros that more or less mimic thefuse map geography within thedevice. These files can be generatedby hand - a rather laborious task - orwith the help of computers andcompilers using descriptivelanguages which take as input nodeallocations in the form of text andlogic equations, more on this later.

The next step in the developmentladder is Complex ProgrammableLogic Devices (CPLD). These are inthe main, evolutionary variations onthe PLD theme. The register flip-flops are placed in a two dimensionalrow and column grid with theinterconnections straddling them, justlike the streets on a city map (Figure2). This allows many more registersto be placed on a die. Cell designscan also be more complex, typicalCPLD devices can have 256 registersor more in a single package, makingthem reasonably powerful. The basicflavour of the month technology isCMOS, which has the advantage oflow power consumption.Programming in the main isperformed at standard logic levels,using a simple serial protocol, doingaway for the need for specialprogramming voltages or specialisthardware (a microprocessor can beused to generate the programmingsignals)

Beyond CPLDs are the genericGate Arrays (GAs), which includeField Programmable Gate Arrays(FPGAs.) The generic FPGAarchitecture is similar to that ofCPLDs, but using much smallertransistor cells and correspondingminiature MOS technologies (CMOSrequires massive surface areas pergate in comparison) FPGAmacrocells can be much smaller in

size and their building blocks can befar more complex. Figures of severalmillion transistors on a die are notuncommon.

One small price to pay with mostcurrent FPGA technology is thatprogramming is not permanent. Inother words, the fuse link informationis stored in RAM within the deviceand must be re -loaded every timepower is applied. This requiresexternal boot loading circuitry knownas configuration devices, which arenothing more than special purposeflash EEPROMs holding an image ofthe fuse map.

Improved processing techniquesnow allow whole sections within aFPGA device to be allocated forspecial tasks such as RAM, specialpurpose I/O or even completeembedded micro -controllers. As anexample of current technology, theXilinx Virtex II/PRO series containsthe equivalent of 4Mb of dual portRAM, over 45,000 registers, I/O thatcan operate in the Gigahertz rangeand four (yes four) embedded PowerPC CPUs, all in a single package.

Let's talk KlingonIf you already know that 'Spartan

delivers Serdes at Gigabyte speeds'has nothing to do with Greeksspreading nasty diseases, you mayperhaps want to skip this section.Mythical and obscure product namesare ripe in the Gate Array world,possibly one of the reasons why theuninitiated may want to shy away.One should not expect these magicnames to be acronyms for anything(at least as far as I know). Just likecar model names in TV commercials,they possibly sound good to the earand convey an element of wizardry tothe people who program them.

Four manufacturers dominate thefield, of which two: Xilinx and Alteraare the brand leaders. Others, such asLattice, Atmel and Actel, command asmaller section of the market, butprovide good competition by theintroduction of innovative featuresand originality in their devices.

Devices are grouped into 'families'with heroic sounding names such asSpartan, Acex or Stratix. These are inthe main, variations of a particularfabrication technology, MOS Type,or cell size in microns. Devices arearranged by size, number of devicesand external package outline. Themore complex devices are used inapplications where a large number ofI/0 pins are required, so they areusually fitted into the largerpackages. This is not always the case,and most FPGA designs end upleaving most of their I/0 pins unused

or unallocated.Families are also divided into

CPLDs and FPGAs as describedabove. In general, most CPLDsinclude permanent program storage,and FPGAs require externalconfiguration devices. This divisionis not always strict, Atmel forexample, have an FPGA technologythat includes permanent programstorage. In the simplest of terms,CPLDs will be used in applicationsrequiring up to 512 registers (flip-flops) and FPGAs where more thanthese are needed.

The main parameters distinguishingmembers of a family are the numberof gates or macrocells per package,the number of I/O pins, the packagetype (which limits the total number ofI/O pins) and other features such ason chip PLLs and special purpose I/Odrivers. Subtle differences in the waythe macrocells are designed allow forsome manufacturers to offer 'better'implementation of commonly usedlogic blocks, for example patentedultra -fast carry look -ahead adders,and tricks to improve performance,such as on -chip clock frequencymultipliers or phase locked loops.

Families do not alwayscomplement each other in a logicalway but overlap widely. This mayseem confusing and can make devicechoosing rather complicated. Thereason for this is partly because themarket is technology driven. New ICfabrication techniques quickly makeprevious families obsolete. With suchshort design cycle times, many usersout there will still be designing using`older' families, which could result ina lot of confusion and aggravation.Manufacturers are keen to continuesupport for previous families, whileat the same time nudge users to moveto newer processes, which are usuallycheaper and more powerful. This canmake sense from the manufacturer'spoint of view, who does not want tobe lumbered with many legacymanufacturing processes. From theuser's point of view however, thispolicy can be a disaster, especiallywhen it comes to maintaining amultitude of end products using arange of different devices. Somefamilies have become more settledand popular than others, this isreflected in prices and stock levelsfrom the various suppliers, animportant factor to consider whenselecting devices in a new design.

The story so farHere is a summary of current status.Of course, no guarantees that thiswill all be superseded by the timeyou read this! The list given below is


Manuf Type Family SupplyV

I/O pins FFs/logicelems

RAM bits Equivgates

Package options

Altera CPLD MAX7000 2.5/3.3/5 36-212 21-512 PLCC,TQFP,PQFP,BGAAltera CPLD MAX3000 3.3 34-158 32-256 PLCC,TQFPXilinx CPLD XC9500 2.5/3.3 36-192 PLCC,PQFP,TQFP,BGAXilinx CPLD Cool runner 1.8/3.3 33-270 32-512 PLCC,PQFP,TQFP,BGAAltera FPGA FLEX6000 3.3/5 71/218 880-2000 10k -24k TQFP,PQFP,BGAAltera FPGA FLEX] OK 2.5/3.3/5 59-470 576-12000 6k -41k 10k -250k PLCC,TQFP,PQFP,BGAAltera FPGA ACEX1K 2.5 66-333 576-5000 13k -50k 10k -100k TQFP,PQFP,BGAAltera FPGA APEX II 1.5 492-1060 16k -67k 420k -1.1M BGAAltera FPGA STRATIX 1.5 340-1300 10k -114k 920k -10M BGAAltera FPGA APEX20K 1.8/2.5 92-808 1200-52k 24k -442k 30k -1.5M TQFP,PQFP,BGAAltera FPGA EXCALI BUR 1.8 186-711 4k -38k 53k -327k 100k -1M BGAAltera FPGA HARDCOPY 1.5/1.8 275-1060 16k -62k 220k -2.4M 400k -3M BGAAltera FPGA MERCURY 1.8 303-486 5k -14k 49k -115k 120k -350k BGAAltera FPGA CYCLONE 1.5 65-301 3k -20k 60k -300k TQFP,PQFP,BGAXilinx FPGA SPARTAN II 2.5 86-284 432-5300 6k -74k 15k -200k PQFP,TQFP,BGAXilinx FPGA SPARTAN IIE 1.8 182-330 1700-7000 24k -96k 50k -300k PQFP,TQFP,BGAXilinx FPGA VIRTEX E 1.8 1 76-804 1.7k -73k 64k -832k 72k -4M PQFP,TQFP,BGAXilinx FPGA VIRTEX II/PRO 1.5 88-1200 3k -125k 216k -10M 40k -8M BGA

by no means complete and onlyoffered as a general guide. Readersshould refer to the publishedliterature and manufacturer'swebsites for the latest information.

CPLDThe current Altera CPLD families arethe MAX7xxx and MAX3xxx. Thelast three digits indicate the numberof flip-flops or registers per device.For example the 7128 is a 128register device. The 7xxx series isnow a 'mature' family (another wordfor obsolete) and it is one of the fewremaining parts that can still operatefrom 5 volt as well as 3.3 volt powersupplies. The newer 3xxx family,recommended for new designs, uses3.3 volt supplies only but its I/O pinsare 5 volt tolerant. Xilinx CPLDfamilies are the 9500 series (with upto 72 registers), and Coolrunner,noted for its low power consumption.Lattice CPLD families are theMachl , Mach2, Mach4 and the latestMach4000 series, which offer up to1024 registers.

Prices for CPLD devices start fromless than a dollar each for the smallerdevices, making CPLDs very costeffective as a replacement for randomglue logic. In general, CPLD prices(and power consumption) are directlyproportional to the number of gates inthe die whether they are used or not.So it does not pay to over specify adesign using a CPLD that is largerthan necessary.

FPGAThe more mature Altera FPGAfamilies are the FLEX6000,FLEXIOK, and the ACEX1K series.The latest Cyclone family is targeted

at superseding these, although thereis still plenty of life left in theexisting ones. More advancedfamilies include Excalibur, with abuilt in ARM 922T CPU processorcore. Mercury, aimed at high speedI/O intensive products. Hardcopy,aimed at bridging the transitionbetween FPGAs and custom ASICs.APEX, a high power, general-purpose device, culminating withSTRATIX at the top end. Xilinxofferings are less complex: theirmature technology includes the XCseries topped by the SPARTANseries in various disguises, andVIRTEX at the top end, again invarious disguises (see table). Top enddevices can offer serious processingpower, with data bandwidths in theGigabit per second range andcomputing power, e.g. DSP withequivalent performance in the 2GigaMAC range.

On power supplies and interfacesHere is a little quiz: a large integratedcircuit may contain several milliontransistors; assume for simplicity thateach has a dynamic load of about amegohm. Simple calculations(assuming a 50% on/off ratio) tell usthat the average resulting loadbetween VCC and GND is less thanan ohm. With a five volt supply, thecorresponding power dissipation willbe about 25 watts. In order to reducethis large sink, manufactures havedeveloped MOS technologiesworking at lower voltage supplies.Since a device that runs at half thevoltage consumes only a quarter ofthe power, this strategy is sound.Most of the newer FPGAs (andCPLDs) operate at 3.3, 2.5, 1.8 or

even 1.5 volts. Many FPGAs havetwo separate power supplies, one forthe internal core (at say 2.5V), andone for the external I/O drivers (atsay 3.3V) this makes themcompatible with external discretelogic circuitry even though internallythey are operating at a lower voltage.

Most CPLDs and FPGAs are notnormally compatible with external 5volt logic, even though some deviceswith 3.3V I/O drivers can accept 5volt logic level inputs (a 3.3V outputfrom a GA device can correctly drivea 5V CMOS or Tm logic gate).

Because of their design, CPLDshave a relatively static currentconsumption, independently ofnumber of gates 'active' and onlyrising slightly at higher clock speeds.On the other hand, the currentconsumption of a FPGA is directlydependent on the number of gatesactive and the clock speed (i.e.number of transitions). Powerdissipation is also dependent on thesoftware programming method used,for example a synchronous systemwhere all the clocks are fed from thesame high speed source, and the useof clock enables, which may or maynot reduce clock dissipation.

The moral of the story is simple,before selecting a device for aproject, make sure you have read allthe documentation and applicationnotes on power supplies and I/Ointerfacing. Most give charts ofpower consumption versus speed,and number of gates in use.

Line drivingFPGAs are heavily used intelecommunications, display panelsand CPU bus drivers. No wonder


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many column inches of advertisingare dedicated at profiling the manytypes of line driving interfacing thesedevices can handle. In order toreduce external component count,bus interface, logic level andimpedance matching components aresometimes built into the GAsthemselves. This allows the devicesto be connected directly to PCIbusses and external transmissionlines. Devices can include options fordifferential outputs and inputs,impedance terminating resistors andvarious voltage thresholdarrangements, including clockrecovery circuits. This provides acomplete in -out (no externalcomponent) interface for externalloads and transmission lines.

In general, data transmission iseffected as a permutation of voltagelevels, transmission impedance anddriving methods such as singleended, differential, or parallel form.The electronics to perform theserialisation and de -serialisation (inother words, clock recovery andparallel to serial conversion) issometimes also built into someFPGA devices as block modules,with some of these working at up toGigabyte speed.

VCC JTAG PS S

the data at their right locations in thefuse map. In the serial method, datais clocked in one bit at a time, using asimple four wire serial protocol. Theprotocol is simple enough to beimplemented with a microprocessor,but clever enough to include facilitiesto allow more than one device to beprogrammed in daisy chain fashionfrom the same source. The moreadvanced devices include functionalJTAG interfaces, which can beshared for programming and for on -site debugging.

CMOS based CPLDs can keep thestored program indefinitely.However, one constraint is that thenumber of times some of thesedevices can be reliably programmedis relatively small (about 100 times).FPGAs can be programmed anynumber of times, but the informationis lost when the device is poweredoff. As already mentioned, thepermanent storage has to be keptoutside the device in an externalEEPROM and transferred across onpower on.

During development, deviceprogramming is usually done via a PC

What is JTAG?

The Joint Test Action Group is a common standard developed tofacilitate in -site simulation and debugging. A target system, which canbe an IC or a full board, is connected to a debugging station, usually aPC using a simple four wire serial interface, which is used for monitoringstatus. In the context of GAs, JTAG is used to allow the PC to initialise 41and read internal registers and I/O states which can then be displayed onthe PC during the debug session. JTAG does not strictly support deviceprogramming, but the same interface circuit can be used to programdevices by means of non-standard commands.

and an interface cable connected to theUSB or parallel port. Theprogramming files take many formats:raw binary, Intel style hex or commaseparated lists of decimal numbers.

Figure 3 shows the circuit diagramof a typical programmer for Alteradevices using the parallel port of aPC. The multitude of resistors arerequired to provide voltage levelcompatibility with both 5Volt and3.3Volt devices. The programmer canbe used to program any device in anyof the Altera families, althoughdifferent value resistors (and

supplies) will be required to programthe lower voltage parts. Theequivalent programmer for Xilinxdevices is very similar, but usesdifferent pinouts. Note that two setsof outputs are shown, one for JTAGand the other for PSS (passive serial).Some devices require JTAG formatfor programming, others PSS (orboth).

In the next part of the article, I shalldescribe how to use the developmentenvironment and how a simpledevelopment system can be puttogether.

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In memoriam 1 L Linsley Hood MILLIt will be with deep regret that many readerswill learn of the death of that respectedregular contributor to this magazine, John

L. Linsley Hood. Born in 1925, JohnLawrence Linsley Hood was educated atReading School, Acton Polytechnic, TheRoyal Technical College (Glasgow) and, after

articles appeared in these pages over a spanof many decades. I have two files of articlessaved from WWIEW, one of my own articlesand one of others'. This second file runs totwo bulging wallet folders, and a quick trawlthrough one of them unearthed nine articlesby J L L H. The earliest I have is his 15-20W

into a.m. radio (E&WW, Oct. 1986, pp 16 -19) and a then important article called TheLiniac (WW, Sept. 1971, pp 437 - 441). Thisdescribed what was in essence an opamp,implemented with discretes, in the days whenopamps were still fairly new, expensive, andof limited performance.

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the war, at Reading University. In 1942 hejoined the G.E.C. Research Laboratories atWembley, working on magnetrondevelopment as a junior member of the team.In 1943 he joined the R.A.F. in aircrew butwas transferred to work on radar. Hesubsequently worked with T.R.E. (Malvern)overseas. After a return to university he joinedthe Windscale Research Laboratories of theAtomic Energy Authority. He was placed incharge of the research laboratories of BritishCellophane Ltd. in 1954. In the late 70s Johnretired from British Cellophane Ltd. and setup his own business from home, as aconsultant and writer of books and articles, asRobins Electronics (Robin being thenickname by which he and his brother wereknown in the forces and elsewhere, onaccount of the surname Hood). In a long anddistinguished career, John published many ofstate-of-the-art articles, which I always foundof the greatest technical interest. From 1962he lived in Taunton, in a house called"Robins", and I often meant to contact him,with a view to paying a visit when in the area.For one reason or another, it never happened,and now unfortunately the opportunity isgone.

I first started reading Wireless World as asixth former in the early 1950s, andremember many of the names of adistinguished group of regular contributors.John was one of these, along with otherfamous names such as Thomas Roddam, L.Nelson -Jones, P. J. Baxandall, Colin Pyckett,`Cathode Ray' (M. G. Scroggie) and others,at least one of whom I know is still with us.John will long be remembered, by manyreaders including younger ones, for his

Class AB Audio Amplifier, Wireless World,July 1970, pp 321 - 324 and the latest Class APower, Electronics World, September 1996,pp 681 - 687, although I'm sure there aremore of his articles tucked away somewhere.

But don't get the impression that John wasonly interested in audio power amplifierdesign, although he did stand in the greattradition of interest in this topic in WirelessWorld, from D. T. N. Williamson onwards.But other articles of his included LinearVoltage Controlled Oscillator (WW, Nov.1973, pp 567 - 569), Putting the quality back

Components listResistors

1 - 900k 19 1.5M.2%2 - 100k, lin. 20 - 1584, 2%3 - 22k 21 - 4.7k4 - 47k 22 - 4.7k5 - 15k, 5% 23 - 5k. preset6 3.3k, 5% 24 3.3k, 5%7 - 22k, 5% 25 - 15k8 - I.8k, 5% 26 820, 5%9 - 470k 27 - 68k, 3%

10 2.5k, lin. (10 toms) 29 39k, 5%/ I - 3.3k, 5% 29 471r, 5%12 - 120k 30 - 2.7k13 - 39k, 5%, 31 - 686, 5%14 - 1k 32 336, 5%15 - 1506, 2% 22 - 220k, 5%16 - 1.5M, 2% 34 lk17- 15M,2°% 35 1.8k18 - 150k, 2% 36 - 3.3k, 5%

37 - 4700Capacitors

1 470n 13 100n2 - 100p/4V 14 - In3 225/20V 15 lOn4 250p/25V 16 - 120p5, 6 - 470p, ganged 17 - 68p7 - trimmer 18 - 330p8 trimmer 19 - 680p9 - 320p/6.4V 20 - 3.3n

10 100a 21 - 680pII 4,7n 22 - 6.8n12 250p/25V 23 - 220n

Diode1 3V, rem

Transistors1 BC109 (C) 4 - 2N4058

2 - MPSA14 5, 6, 7 - BC1093 - 2544302

John's interests included the importanttopic of measurements. Lord Kelvin orRutherford or some similar luminary oncesaid that if you cannot measure something,you don't understand it - a truer statementyou will not come across in a very long time.An exceedingly useful piece of measurementequipment for anyone interested in audio, is adistortion meter. John published in WW, July1972, pp 306 - 308, a design for a PortableDistortion Monitor, designed using discretesemiconductors and based on an all -pass filtersection implemented with a Wien Bridgecircuit. This was intended for use inconjunction with an oscilloscope to view the"residual" - the distortion products - once thefundamental has been suppressed, or with anAC millivoltmeter to obtain an approximatefigure for the THD. I built at least two ofthese, one using a twin gang 500pF capacitoras in the original design, and one using fixedcapacitors and a two -gang pot, to avoid thehigh circuit impedances otherwise involved.The design, though since overtaken by laterdevelopments, was so important in its dayand such a good example of what can beachieved by innovative circuit design usingdiscretes, that I have asked the Editor to findroom to reproduce the circuit and componentlist herewith, scanned in from a rather dog-eared, scribbled -on and yellowed -with -agecopy from my files, somewhat tidied up withthe aid of the ever invaluable Paintshop Pro.

John must have been well known to formereditors of EW/WW, such as Martin Eccles,Frank Ogden, Phil Darrington, Tom Ivall andothers, and many readers, like me, will feelthat they had come to know him a little also.He will be sorely missed.


A new monitoringtool for 5.1 audioIn this article Richard Brice proposes a new visual -display monitoringtool for sound engineers working with 5.1 audio. It combines theadvantages of the analytical power of the familiar stereo Lissajousdisplay with a visualisation of the periphonic sound -field pioneered inthe 'Jellyfish' display. The background and theory are discussed and apractical, analogue circuit implementation is given

Multi -channel audio has itshistorical roots in the cinemaindustry where a sense of

periphonic sound has long beenthought a great benefit to the overallentertainment. Despite a multiplicityof products, a standard has graduallyemerged which, whilst it fails toprovide accurate periphoniclocalisation, nonetheless provides adegree of audio 'envelopment' whichis deemed by film makers andaudiences alike to be the mostimportant factor in the enhancementof their entertainment. That standardhas become known as 5.1 multi-channel audio; these numbersreferring to the fact that the systemcomprises five full -bandwidthchannels and one reduced bandwidth,low frequency enhancement (LFE)

Figure 1: Thestandard 5.1 listeningarrangement

channel arranged as shown inFigure 1.

The low frequency channel (LFE)was originally termed the 'BabyBoom' channel for its originaladoption in Star Wars in the latenineteen -seventies and is reservedand engineered to provide thephysical sensation we associate withdeep space explosions (albeit thatthese take place in a vacuum!).

MonitoringBecause of its increasingly widespread adoption, the requirement fora suitable monitoring device for 5.1audio is becoming similarlywidespread. At the present time, themost common is the presentation ofthree quasi -stereo channels; the 5.1audio being broken down into three

pairs in the following way: left front, right front (LF, RF) left surround, right surround (LS, RS) centre and low frequency

enhancement (C & LFE)Unfortunately, the presentation of

these signals, either on peak -readingtype or power -averaging type meters,is both difficult to interpret and givesvery little visual information aboutthe 'enveloping' 5.1 sound -field. Anattempt has been made to improveupon this situation by DK-Audio A/Sof Denmark in what they have termedthe 'Jellyfish display' as illustrated inFigure 2.

In this computer -generatedpresentation, the positions of the five,full range loudspeakers are markedon a graticule and the amplitudedistribution of the sound -field is usedto modulate a visual 'blob' which sitsin the middle of the screen. Thisamplitude induced distortion of the`blob' is very highly damped, suchthat if a signal of consistent energy isused to energise - for example - theleft front loudspeaker, then a tentaclegrows out of the blob in the directionof the speaker position. Whenenergised with complex multi-channel programme the overall affectresembles a dancing jellyfish!

Whilst this approach is rather fun,in my own experimental 5.1 mixingsessions, I have found it to be notterribly useful. The problem is thatthe damping is so high that thedisplay fails to register all but thelargest contours of programmedynamics. In addition, it simply


Figure 2: The 'Jellyfish display' fromDK-AUDIO

displays the energy distribution aboutthe periphery of the listening space:which is the one thing your ears canreliably tell you! What is required isa much 'faster' display, and one thatgives an indication of phaserelationships between the channels.

PhaseThe phase relationships that existbetween channels of a multi -channelaudio system represent criticalinformation to a recording or qualitycontrol engineer. This is because -although multi -channel audiosystems are largely based onamplitude -derived stereophony -faults in microphone placement andin subsequent engineering andprocessing can produce phase -errorsand anomalies that result in poorlocalisation or bass cancellation andcomb -filter effects; especially whendown -mixed to stereo or to mono.An indication of the phaserelationships between the channelscan alert the sound engineer to thesepossible problems in a way thattired, over -worked ears cannotalways do.

The requirement to view the phaserelationships between the channels ofa multi -channel audio system relying

right

on summing localisation has beenwell established for many years:especially so in television, whererapid quality judgements have to bemade in perhaps less than idealconditions. The solution is a displayof a complex Lissajous Figure',derived from the left and right of thestandard stereo inputs. In this type ofdisplay the plates of an oscilloscopeare fed with an amplified audiosignal. This two-dimensional displayhas a particular advantage in that itpermits the engineer easily to inspectthe degree to which the left and rightsignals are correlated; which is to saythe degree to which a stereo signalcontains in -phase, mono componentsand the degree to which it containsout -of -phase or stereo components.

In the usual arrangement, the Yplates inside the oscilloscope aredriven with a signal that is the sum ofthe left and right input signal (suitablyamplified). The X plates are drivenwith a signal derived from the stereodifference signal (R -L), as shown inFigure 3. Note that the left signal willcreate a single moving line along thediagonal L axis as shown. The rightsignal clearly does the same thingalong the R axis. A mono (L=R)signal will create a single vertical lineand an out -of -phase mono signal willproduce a horizontal line. A stereosignal produces a woolly ball centredon the origin; its vertical extentgoverned by the degree of L/Rcorrelation and its horizontal extentgoverned by L/R de -correlation. Andherein lies the polar display'sparticular power, that it can be used toasses the character of a stereo signal,alerting the engineer to possibletransmission or recording problems,as illustrated in Figure 3.

The presentation of simultaneousleft and right signals in a Lissajousdisplay may usefully be thought of as

L+R

R -L

left

out of phase narrow stereo

Figure 3: The stereo Lissajous display.

mono

L+R

R -L

wide stereo

Figure 4: The initial experimental prototype

the presentation of a complex planesuch that any instantaneous soundpressure, caused by the combinationof the signals issuing from the left andright loudspeakers, may be thought ofas a complex number where thedifference component is the real partand the sum, the imaginary.

A New Monitoring DisplayThis article outlines the developmentof a new visual display device for themixing and quality monitoring of 5.1audio signals. It combines theattributes of the agility of the peakprogramme meter, the presentation ofthe distribution of the overall soundfield of the Jellyfish display and theanalytical power of the complexLissajous display.

TheoryPractical 5.1 audio systems treat thecreation of phantom auditory eventson the periphery of the circle onwhich lie the five cardinalloudspeaker positions by means of apiecewise stereophony. A study of5.1 audio books and articles, as wellas investigation of practicalimplementations reveals theorthodoxy is the following:

Phantom images are reliablycreated by the energising - withappropriate amplitude differencesthe two adjacent channels to theparticular phantom position.

In the case of the forward arc, thisis familiar from conventionalstereophony. However, the Centrechannel loudspeaker complicates thesituation and this is dealt with later.Interestingly, contemporary usagetends still towards the use ofconventional, two -loudspeakerstereophony (LF, RF only) for music -bed and front effects, with the Centrechannel being reserved for dialogueor a mix of dialogue and anarithmetically derived average of leftand right. This theory is extended tocover the rear arc (between LS andRS) and for side images between LFand LS and RF and RS. Thismonitoring tool support

electron 'world...the ubiquitous ivor catt has a go at the emc fraternity 52 cell phones surge ahead...

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