future technology magazine - my … · future technology magazine issue 1302 design note: ......

F U T U R E T E C H N O L O G Y M A G A Z I N E

I S S U E 1 3 0 2

Design Note: page 13AudioStreamer dev board provides blueprint for FLAC, MP3 and Ogg Vorbis decoder designs

Technical View: pages 20-23 How to make machines see, plus a new approachto transmitter design in remote controls

Application Spotlight: pages 15-18All-analogue active noise cancellation ICs from ams offer very low power consumption

Component Focus: pages 2-12 Microchip’s small PIC32 microcontrollers gain 25% performance boost

In association with www.my-boardclub.com

New 30A fully-encapsulated powermoduleIntersil has introduced the ISL8225M, theindustry’s first 30A fully encapsulated powermodule. The ISL8225M simplifies the designof high-performance board-mounted powersolutions.

The ISL8225M can deliver up to 100Woutput power from a small 17mm x 17mmfootprint. Its two 15A outputs may be usedindependently or combined to deliver asingle 30A output. Current sharing andphase interleaving allow up to six modulesto be paralleled to make a 180A output.Because of its excellent efficiency and lowthermal resistance, the module can operateat full power without heatsinks or fans.

4G LTE modules in smaller form factorSierra Wireless has introduced its secondgeneration of 4G LTE AirPrime™ embeddedwireless modules. The six new additions tothe AirPrime EM series and MC seriessupport 4G LTE networks worldwide andare compatible with the Windows® 8operating system. The new devices offerspace savings, reduced power consumptionand support for more operators’ networks.

Future Electronics to distribute LEDproducts from LG InnotekFuture Lighting Solutions, a division ofFuture Electronics, and LG Innotek, anaffiliate of LG Group, have announced astrategic worldwide distribution agreementthat will introduce LG Innotek’s entire portfolioof LED lighting solutions to the market. Theportfolio features one of the industry’sbroadest selections of LED products, fromLED packages to integrated solutions.

Microchip launches JukeBlox® 3.2 SDKwireless audio platform Microchip has introduced the first Wi-Fi®audio connectivity platform to support allmajor mobile and PC operating systems andthe DLNA® standard. The new JukeBlox® 3.2platform and software development kitoperates on all of Microchip’s existing JukeBloxnetwork media processors and modules. It also supports JB Cloud, which enablesthe direct streaming of cloud-based musicservices while using mobile devices asremote controls. This eliminates the need formobile devices to act as servers, where theyconsume power and must stop the music totake phone calls or support other personalaudio functions.

S TA R P R O D U C T

2 E M A I L I N F O @ M Y- F T M . C O M F O R S A M P L E S A N D D ATA S H E E T S

The HEDR-5xxx series encoders are compatiblewith the snap-in baseplate of the HEDS-5xxxseries for attachment to a motor, permittingeasy replacement and upgrade to the latestdevices offering increased resolution. Thebaseplate is fixed to the motor endplate usingadhesive and screws, and holds the motorsecurely in place over the motor spindle. An M3set screw secures the encoder’s codewheel tothe spindle.

Internally, the encoder comprises thecodewheel, LED source, detector andintegrated circuitry.

The three-channel output provides a once-per-revolution index pulse (I) with 90° gating andtwo square-wave outputs in quadrature (A,B)indicating rotational direction.

HEDR-5xxx series encoders accommodateshaft diameters of 2mm to 8mm and arecapable of operation in high-temperatureenvironments up to 100°C. Three connector-cable configurations are available forconnecting to the host system. These providedesigners with a choice of a ribbon cable withan attached 10-way polarised IDC connectorfor line-driver connection, or shielded coaxialcable with either single-ended or differentialline-driver signalling.

Offering quick assembly, operation from asingle 5V supply, IP40 sealing and freedomfrom any need to apply signal adjustment, theHEDR-5xxx series provides convenient,accurate and precise motion sensing for motormanufacturers and system integrators.

AVAGO TECHNOLOGIES

my-ftm.com/130201FOR PARTS ANDLATEST PRICING

©Copyright 2013 Future Electronics Ltd. All trademarks contained herein arethe property of their respective owners. Applications for product samples,badge boards, demonstration boards, Future-Blox Boards and otheradvertised materials from Future Electronics are subject to qualification.

Newsin brief

HEDR-5xxx high-resolution opticalencoders from Avago Technologies aredirect replacements for the existingHEDS-5xxx series, offering increasedresolution of up to 3600 Counts PerRevolution (CPR) while continuing tooffer ease of use and versatility at acompetitive price.

Encoder options and part numbers:

HEDR-5xx encoders are robust, easy to use, and a directreplacement for the lower-resolution HEDS-5xx series

Optical encoders provide easyupgrade to increased resolution

APPLICATIONS• Industrial printers• Plotters• Tape drives• Positioning tables• Automatic handlers

FEATURES• Housing dimensions:

30mm (W) x 35mm (L) x 20mm (H)• Operating-temperature range:

-40°C to 100°C• Motor-shaft length: 11.5mm to 13.5mm• 2-screw or 3-screw baseplate-to-motor

mounting

ENERGY MEDICAL LIGHTING INDUSTRY SECURITY AUTOMOTIVE


HEDR-5 x x x - xx x x

Mounting type Output type Output cable type CPR Index gating Shaft diameter5 - standard E - voltage (TTL) 1 - shielded B2 - 1200 0° - 90° 0 - 2mm

6 - external ears C - open collector 2 - ribbon B4 - 1250 1 - 3mmL - line driver B6 - 1440 2 - 1/8”

B8 - 1500 3 - 5/32”BB - 1800 4 - 3/16”BH - 2048 5 - ¼”BL - 2400 6 - 4mmBP - 2500 7 - 5mmBS - 2880 8 - 6mmBV - 3000 9 - 8mmBY - 3600

3V I S I T T H E O N L I N E F T M M A G A Z I N E AT: W WW . M Y- F T M . C O M

C O M P O N E N T F O C U S

25% performance boost for 32-bit PIC® microcontrollersspeeds-up feature-rich applications

Extra performance gives developers freedom to add high-value features such as a sophisticatedgraphical user interface

MICROCHIP

Ultrafast power diode enhances power-supplyefficiency and ruggedness

Power-supply designers can improve energy efficiency, ruggedness and dynamic performance using the NUR460P ultrafast power diode

NXP Semiconductors’ NUR460P is a600V ultrafast power diode in aSOD141 (DO-201AD) axial-lead plasticpackage, which helps enhance power-supply efficiency thanks to its lowforward-voltage drop of 0.82V (typicalat 3A and 150°C) and low leakagecurrent of 10µA at 25°C.

The diode is rated for average forward currentup to 4A, and can withstand non-repetitivepeak forward current up to 110A. With lowpackage thermal resistance and maximumoperating junction temperature of 175°C, it isable to perform reliably with high current andunder harsh operating conditions.

The NUR460P also offers fast dynamicperformance, with reverse-recovery time aslow as 50ns under step-recovery testconditions.

NXP SEMICONDUCTORS

Microchip’s latest 32-bit PIC32MX1/MX2microcontrollers, now operating up to50MHz or 83DMIPS for a 25%performance boost, help designers toovercome speed bottlenecks whileproviding advantages such as feature-packed peripherals and 4-channel DMA.

The PIC32MX1/MX2series includesMicrochip’s smallest 32-bit MCU, with sizesdown to 5mm x 5mmand a 0.5mm pitch, aswell as the lowest-costPIC32 MCUs. Thesedevices include up to128kbyte Flash and32kbyte RAM, andintegrate peripherals fortouch-sensing, audio-processing andadvanced controlapplications. Theintegrated peripheralsinclude a hardwaremodule for adding

APPLICATIONS• Discontinuous Current Mode (DCM)

Power Factor Correction (PFC)• High-frequency switched-mode power

supplies

FEATURES• Fast switching• High voltage capability• Low forward-voltage drop• Low leakage current• Low thermal resistance• Soft recovery characteristic



APPLICATIONS• Graphic displays and touch screens• USB device/host applications• Industrial-grade and commercial noise-

cancelling headsets• Medical and industrial displays

FEATURES• Ethernet/USB/CAN connectivity• High-performance audio peripherals• 80MHz internal bus and cache• Package options:

• 28-pin SOIC, SPDIP, SSOP• 36-pin VTLA• 44-pin QFN, TQFP and VTLA

• Temperature Range: -40°C to 105°C



EVALUATIONBOARDS AT my-boardclub.com/ftm

DETAILSON PAGE

19

ON Semi’s NCP125x: page 10NXP’s BYC30X-600P: page 9PARTNERWORKING

ON Semi’s LC717A00AJ: page 4Semtech’s SX951x: page 11PARTNERWORKINGmTouch™ capacitive-touch buttons or advanced

sensors; an 8-bit Parallel Master Port (PMP)interface for graphics or external memory; a10-bit 1-Msample/s 13-channel ADC andserial communications peripherals. The MX2series also adds USB On-The-Go capabilities.

The improved performance of thePIC32MX1/MX2 enables designers to overcomespeed bottlenecks and develop productscombining audio, touch-sense functionality,embedded control capabilities and USBcommunication in a single microcontroller.

Capacitive-touch IC simplifiesuser-interface enhancement


The LC717A00AJ capacitive-touch IC delivers increased convenience and power efficiency,without losing performance or flexibility

The ON Semiconductor LC717A00AJtouch-switch IC requires no externalcomponents, consumes low active andstandby power, and can be used as astandalone controller or connected toa host processor.


By minimising demand for additional circuitry,the LC717A00AJ simplifies replacement ofmechanical or membrane switches with acapacitive-sensor array of up to eightchannels. High sensitivity, permitting touchdetection at a depth of up to 3mm, makes thisIC a strong choice for a variety of applicationssuch as commercial or industrial equipmentwhere users may be wearing gloves.

With active-mode current of just 350µA andstandby current of 2µA, theLC717A00AJ allows the userinterface to be enhanced withminimal impact on overallpower budget or battery life.The LC717A00AJ features anintegrated programmabledifferential amplifier, whichenhances immunity toexternal noise therebyallowing dependable touchdetection in all environments.Programming the amplifierallows designers to adjust thebehaviour of the IC to suittheir application. TheLC717A00AJ integrates a

ON SEMICONDUCTOR

Advanced metal-strip resistors increase powerdensity and accuracy

Vishay's latest-generation power resistors deliver the highest power-handling capability inrelation to size

Vishay WSLP2010 Power Metal Strip®

resistors provide high power density forprecision sensing and pulse applications,and offer extremely low resistancevalues down to 0.001Ω, stableresistance tolerances to 0.5%, and aTemperature Coefficient of Resistance(TCR) better than 20ppm/ºC ensuringconsistent accuracy over awide temperature range.

The high performance andstability of the WSLP2010series is achieved using aproprietary processingtechnique and advancedconstruction incorporating asolid metal nickel-chrome ormanganese-copper alloyresistive element. This resultsin a resistor with a high 2Wpower rating and an operating-temperature range of -65°C to

The WSLP2010 series is ideal for applicationssuch as down-hole test and measurementequipment in the oil and gas industries,automotive engine management units, Li-ionbattery safety and management circuits, andinverter controls for HVAC systems.

VISHAY

APPLICATIONS• Printers and scanners• Commercial appliances• Industrial controls• White goods• Consumer-electronic products

FEATURES• Supply-voltage range: 2.6V to 5.5V• Compatible with 3V or 5V logic• Power-on reset• Automatic self calibration• Integrated oscillator• Interrupt-output pin



APPLICATIONS• General switched-mode and linear power

supplies• Instrumentation and power amplifiers• Automotive electronic controls• Industrial controls and motor drives• Computer power supplies and regulators• Battery-management systems

FEATURES• 0.5% and 1.0% tolerances• 0.5nH to 5nH inductance• Thermal EMF below 3µV/°C• 2010 case size• All-welded construction• Meets AEC-Q200 requirements



Microchip’s PIC32MX1/MX2: page 3Semtech’s SX951x: page 11PARTNERWORKING

selectable I2C/SPI port for communication withthe host controller, through which amplifiersettings and other parameters such as switch-scan and touch-response times can beselected. There is also an external Gain pin forsetting amplifier gain when the LC717A00AJ isused in standalone mode.

170°C, while maintaining the superior electricalcharacteristics of the Power Metal Stripconstruction.

Offering the highest power density amongVishay’s portfolio of Power Metal Stripresistors, the WSLP2010 devices allow for thedesign of high-power circuits featuring thesmallest possible resistor for higher-performance end-products. Furthermore, thehigh-temperature capability of these resistorsallows use in harsh, high-temperatureenvironments without sacrificing power ratingor electrical performance.


Compact Trench MOSFETs maximise efficiencyand switching performance

NXP SEMICONDUCTORS

Low-capacitance TVS diode array provides optimalESD protection for USB3.0 and HDMI 1.4

LITTELFUSE

APPLICATIONS• LED/LCD/PDP televisions• Set-top boxes• DVD and Blu-ray players• Personal media players• Ultrabook or notebook PCs• Digital cameras

FEATURES• Over-voltage and transient protection

• ESD IEC 61000-4-2:±12kV contact, ±25kV air

• EFT IEC61000-4-4: 40A (tP=5/50ns)

• Lightning IEC 61000-4-5: 4A (tP=8/20µs)

• Ultra-low capacitance of 0.5pF• Small form factor µDFN-14 package

3.5mm x 1.35mm x 0.5mm



APPLICATIONS• Relay drivers• LED backlight drivers• Low-side load switching• Switching circuits

FEATURES• 1µA drain leakage current• Thermally efficient enlarged 4th pin (Drain)• Operating junction-temperature range:

-55°C to 150°C



The Littelfuse SP3012-04UTG andSP3012-06UTG are low-capacitanceTransient-Voltage Suppression (TVS)diode arrays for protecting sensitivechipsets with high-speeddata lines against ESDand other over-voltagetransients. Their very lowdynamic resistance of0.4Ω provides up to a 66%reduction in clampingvoltage compared toother competitive devices,which helps to ensure reliableproduct performance in the field.

NXP Semiconductors continues togrow its portfolio of small-signalMOSFETs in small and medium-powerpackages, with the arrival of two100V N-channel devices that usethe latest Trench technology toachieve high current-handlingcapability with low on-stateresistance.

The PMT200EN combines a highmaximum rated drain current of3.3A with very low typical on-stateresistance of 190mΩ, measured at25°C. This device has total gatecharge (QG) of 7.4nC and gate-draincharge (QGD) of 1.9nC.

The PMT760EN has maximum ratedcurrent of 1.3A and on-state resistanceof 760mΩ. With very low QG of 2.4nC andQGD of 0.6nC, the PMT760EN is ideal forapplications requiring responsive and efficientswitching.

Both types can be operated using logic-levelgate-drive circuitry, and can tolerate gatevoltages up to ±20V. Fast switchingperformance is assured, with typical turn-ondelay times less than 4ns and typical turn-off

delay times less than 11ns, as wellas rise and fall times of less than5ns for each device.

The PMT200ENand PMT760EN areideal for LCD-TVbacklight drivingand general-purpose LEDdriving, as wellas high-voltageload switchesfor industrialapplications.The devices arepart of NXP’sextensive rangeof small-signal

MOSFETs, whichcontains P- and N-channel types

from 12V to 300V with very low resistancevalues and includes variants such asautomotive-qualified and ESD-protected types.

The devices are capable of protecting four orsix I/Os respectively and can absorb repetitiveESD strikes above the maximum level specifiedin the IEC61000-4-2 international standard(Level 4) without performance degradation.With an extremely low capacitance of 0.5pF

per line the SP3012 series minimises signaldegradation thereby helping to preserve systemperformance while reducing a designer’sdependency on accurate trace-impedancesimulators.

The SP3012-06UTG is specifically designedfor USB3.0 by integrating all six channels ofprotection into a 3.5mm x 1.35mm µDFNpackage reducing the PCB footprint by morethan 50% compared to other integrated, six-channel solutions. Furthermore, the package

design allows the traces to flow directlybeneath the device, minimising PCB

trace discontinuities which canalso impair signal integrity.


Stronger power MOSFETs boost systemreliability and efficiency

StrongIRFET meets the needs of high-power electric tractionapplications

International Rectifier StrongIRFET™ 40Vpower MOSFETs combine ultra-lowon-state resistance with high currentratings, enabling improved systemreliability with high energy efficiency andalso helping to reduce part count whenreplacing lower-performing devices.


Additional benefits of the family include high gate,avalanche and dynamic dV/dt ruggedness,fully characterised capacitance and avalanche

Safe Operating Area (SOA), and enhancedbody-diode dV/dt and dI/dt capability.

This new family of StrongIRFET devicescomprises 14 parts spanning a wide range ofparameters and offering benchmarkperformance for the industrial market. Inaddition, a diverse package offering providesextra flexibility for designers to select themost suitable device for any application. Theycan be used in many types of equipmentsuch as battery packs, inverters, ballasts,OR-ing and hot-swapping circuits,Uninterruptible Power Supplies (UPS), solarinverters, forklift trucks, power tools andmobility scooters.

INTERNATIONAL RECTIFIER

Small LDOs offer high PSRRNXP SEMICONDUCTORS

APPLICATIONS• Motor drives• Battery-powered circuits• Half-bridge and full-bridge topologies• Electronic ballasts• Synchronous rectifiers• Resonant-mode power supplies• OR-ing and redundant power switches• DC/DC and AC/DC converters

FEATURES• 40V breakdown voltage• Rated-current range: 85A to 195A• 175°C maximum operating junction

temperature



APPLICATIONS• Point-of-load applications in which

FPGAs, microcontrollers or SoCs arepowered by a low-voltage rail

• Digital still cameras• Video cameras

FEATURES• 0.1µA quiescent current in shut-down

mode • 30µVrms output noise voltage at

10Hz to 100kHz• 150µs turn-on time• 55dB Power Supply Rejection Ratio

(PSRR) at 1kHz • Output-current limiter• ESD protection up to 10kV (Human Body

Model)



Part NumberMax. Continuous

Drain Current (ID) @25°C

Max. On-StateResistance (RDS(ON)) @

VGS = 10V

Gate charge (QG) @VGS = 10V Package

IRFR7440TRPbF 90A 2.5mΩ 89nC D-PakIRFS7437TRL7PP 195A 1.5mΩ 150nC D2-7pinIRFS7437TRLPbF 195A 1.8mΩ 150nC D2-PakIRFS7440TRLPbF 120A 2.8mΩ 90nC D2-PakIRFH7004TRPbF 100A 1.4mΩ 134nC PQFN56IRFH7440TRPbF 85A 2.4mΩ 92nC PQFN56IRFH7446TRPbF 85A 3.3mΩ 65nC PQFN56IRF7946TRPbF 90A 1.4mΩ 141nC DirectFET® Medium CanIRFB7430PbF 195A 1.3mΩ 300nC TO-220ABIRFB7434PbF 195A 1.6mΩ 216nC TO-220ABIRFB7437PbF 195A 2.0mΩ 150nC TO-220ABIRFB7440PbF 120A 2.5mΩ 90nC TO-220ABIRFB7446PbF 118A 3.3mΩ 62nC TO-220ABIRFP7430PbF 195A 1.3mΩ 300nC TO-247

Operating at inputvoltages ranging from2.3V to 5.5V, the familyprovides a choice of 16fixed output voltagesbetween 1.2V and 3.6V.Output voltage variation istypically ±0.5% with amaximum of ±4%.

The LD6836 family isavailable in two sets ofvariants. The LD6836x/xxH

devices show a high-ohmic state at the outputpin in disabled mode. The LD6836x/xxP partscontain a pull-down switching transistor toprovide a low-ohmic output state (auto-discharge function).

Two package options are alsoavailable. The LD6836TDdevices are offered in a smallSOT753 SMD plasticpackage. The LD6836CX4and LD6836CX4/C devicesare in a Wafer-Level Chip-Scale Package (WLCSP)with a 0.4mm pitch,making them ideal foruse in portableapplications requiring theuse of the smallestpossible components.

The LD6836 series is a family of smallLDO regulators offering a typical voltagedrop of 90mV at their 300mA maximumoutput current.




Solid tantalum capacitors provide highcapacitance and voltage ratings

VISHAY

The latest AK3 series TVS diodes are fast-reacting devices that provide 3kA surgecapability according to the IEC61000-4-5standard that defines an 8/20µs test pulse.Response time is less than 1µs, and thedevices are capable of supporting a very low

LITTELFUSE

The devices are availableat three different voltageratings: the 4V parts,rated at 40°C, areavailable in 22µF, 100µFand 220µF versions. The6.3V variants are offered in 10µF and 47µFversions. The parts with the highest, 10V,rating are offered in 22µF, 33µF and 100µFvariants.

The 298W family of tantalum capacitors has a±20% capacitance tolerance as standard,although devices with a ±10% capacitancetolerance can also be specified.

The capacitor family provides a choice ofsmall parts, including devices with an 0603and an 0402 footprint. They are available in

L-shaped face-downterminations. Terminationsare 100% matte tin asstandard, although gold-plated terminations areavailable as an option.

The 298W parts areshipped in 8mm tape-and-reel packagingconforming to EIA-481,and reeling conforming tothe IEC 60286-3 7"

standard. Vishay recommends that solidtantalum capacitors be vacuum-sealed withdesiccant tape, and that reels be stored at40°C and 65% relative humidity.

APPLICATIONS• Telecom-infrastructure equipment• Industrial Transient-Voltage Surge-

Suppressor (TVSS) systems• Railway trackside signalling and control

cabinets• Defence and avionics equipment• Power-grid and distribution systems

FEATURES• Bidirectional operation• Low slope resistance• Leakage current in the order of µA• 150°C maximum operating temperature• No inherent wear-out mechanism when

operated within peak pulse-current rating



APPLICATIONS• Industrial equipment• Consumer electronics devices• Communications equipment • Portable devices• Home appliances

FEATURES• Operating temperature:

-55°C to 85°C and to 125°C with voltagederating



Vishay has released a new line ofleadframeless moulded chip capacitors,the 298W family,offering theindustry’s highestcapacitance density.

The Littelfuse AK3 series of high-powerTransient-Voltage Suppressor (TVS)diodes, targets high-current applications,and combine exclusive Foldbaktechnology for enhanced protection, asharp breakdown voltage, andextremely compact dimensions that helpsave board space and simplify design.

Part Number StandoffVoltage

MinimumBreakdown

Voltage @ TestCurrent

MaximumBreakdown

Voltage @ TestCurrent

Maximum ClampingVoltage at

3kA Pulse Current

Test Current

LeakageCurrent @StandoffVoltage

AK3-015C 15V 16V 19V 28V 10mA 20µAAK3-030C 30V 32V 37V 90V 10mA 20µAAK3-058C 58V 64V 70V 110V 10mA 20µAAK3-066C 66V 72V 80V 120V 10mA 20µAAK3-076C 76V 85V 95V 140V 10mA 20µAAK3-380C 380V 401V 443V 520V 10mA 20µAAK3-430C 430V 440V 490V 625V 10mA 20µA

High-power TVS diodes save 90% ofspace, deliver enhanced protection

clamping voltage. They can also be connectedin series and/or parallel for use in applicationsrequiring higher voltage and/or more robustprotection, respectively.

Littelfuse’s Foldbak technology reduces theclamping voltage to a level below the deviceavalanche state but above the rated workingvoltage, which minimises any voltage rise dueto increased current conduction and therebyprovides the best possible protection. Thesharp breakdown-voltage characteristic, within±5% of the rated breakdown voltage (VBR),allows the diodes to respond very quickly toelectrical line transients.

The ultra-compact design of the AK3 seriesmeans it has just one-tenth the volume oftraditional passive device solutions. Thissimplifies circuit design configurations andreduces the space required on circuit boards,thereby greatly lowering the overall costs.



Low-profile suppressor providessurge protection up to 600W

The SlimSMA sub-millimetre profile allows rugged electronics to be built in extremely slim enclosures

Vishay Intertechnology has introduced a new series of surface-mount TransZorb®

Transient Voltage Suppressors (TVS) in the SlimSMA™ DO-221AC package, offering acombination of a very low 0.95mm profile and a high surge capability up to 600W at10/1000µs. The protection capability provided by the SMA6F reaches 4kW at 8/20µs.

compatible and offer a surge capability that is50% higher at 10/1000µs.

Design engineers using the SMA6F serieswill also benefit from its low clamping voltages,which range from 9.2V to 31.4V at 10/1000µsand from 13.4V to 36.8V at 8/20µs. Thesevalues are 3-9% lower than those of currentTVS devices in the SMB package.

The series consists of 16 TVS devices withstand-off voltages from 5V to 20V.

VISHAY

The SMA6F TVSparts are intendedfor the protectionof sensitiveelectronic circuitsagainst voltagetransients inducedby inductive loadswitching andlightning in space-constrainedapplications.These TVSdevices are 50%thinner thancomparable partsin the traditionalSMA package, yetare footprint

APPLICATIONS• Consumer electronics• Computing equipment • Industrial electronics• Telecommunications

FEATURES• Uni-directional only• 15kV (air) ESD capability• 8kV (contact) ESD capability• Operating temperature: -55°C to 175°C



Shift register enables use of microcontrollerswith fewer pins

NXP SEMICONDUCTORS APPLICATIONS• Automotive display clusters using multiple

LEDs• Fault-status indicators• 7-segment displays

FEATURES• Automotive product qualification in

accordance with AEC-Q100 (Grade 1)• Operating temperature:

-40°C to 125°C• Low on-state resistance• 8 Power EDNMOS transistor outputs of

100mA continuous current• 250mA current-limit capability• 33V output clamping voltage • 30mJ avalanche-energy capability• Low power consumption• ESD protection:

• HBM AEC-Q100-002 revision Dexceeds 2500V

• CDM AEC-Q100-011 revision Bexceeds 1000V



The NPIC6C596-Q100features a serial input and aserial output to enable cascading,and an asynchronous Master Reset (MR)input. A low logic signal at the MR pin resetsboth the shift register and storage register.

Data is shifted on the low-to-hightransitions of the shift-register clock input. Thedata in the shift register is transferred to the

The NPIC6C596-Q100 from NXPSemiconductors is an automotive-qualified 8-bit serial-in and serial- orparallel-out shift register with astorage register and open-drainoutputs. It can be used to expandthe availability of I/O lines andtherefore reduce the number ofmicrocontrollers on a board,or to enable the use oflower-cost MCUs withfewer pins.

storage register on a low-to-high transition ofthe storage-register clock input. If both clocksare connected together, the shift register isalways one clock pulse ahead of the storageregister.

To provide additional hold time in cascadedapplications, the serial output is clocked outon the falling edge of the shift register’s clockinput. Data in the storage register drives thegate of the output Extended-Drain NMOS

(EDNMOS) transistor whenever theOutput-Enable (OE) input isLow. A High signal on the OEpin causes the outputs toassume a high-impedanceOff state. The open-drain outputs are

eight EDNMOS transistors ratedfor 33V and 100mA continuous-

current output. This means thatthey are suitable for use with devices

that require moderate load power suchas LEDs. Integrated voltage clamps in

the outputs provide protection againstinductive transients, which means thetransistors can also drive devices such asrelays, solenoids and other low-current ormedium-voltage loads.



Ultra-fast power diode cuts switching lossesin a MOSFET or IGBT

NXP SEMICONDUCTORS

3W high-power RGB LED saves cost and space,delivers superior performance

TitanBrite RGB LEDs deliver high brightness and intensity, within compact dimensions, for signage and lighting applications

Lumex’s TitanBrite™ 3W high-powerRGB LED is ideal for a wide variety ofapplications that require bright, intenseillumination with low powerconsumption, especially in sectorssuch as electronic signage, automotiveinteriors, industrial controls, medicaldevices and small-space lighting.

This unique high-power RGB LED representsthe latest generation of technology designedto enhance energy efficiency and providedesign engineers with greater opportunities forcolour innovation. The use of Lumex’sTitanBrite 3W RGB LED can yield cost savingsof up to 30%, as well as 67% saving inpackage real-estate when compared to theuse of individual high-power red, green andblue LEDs.

A single TitanBrite RGB LED, part numberSML-LX1610RGBW/A, generates red, green

and blue light intensity of 8lm, 25lm and 20lmrespectively at 300mA (red), 350mA (green)and 350mA (blue).

LUMEX

APPLICATIONS• High-output signage• Decorative lighting• Indicator lighting• Portable medical devices• Multicolour applications

FEATURES• Ultra-bright, full-colour output• 3W high-power package• Operating-temperature range:

-30°C to 85°C• 3.3mm off-the-board height• 10mm x 16mm circuit-board footprint



APPLICATIONS• Continuous-current mode power-factor

correction• Half-bridge switched-mode power

supplies• Full-bridge switched-mode power

supplies

FEATURES• Low leakage current• Low reverse-recovery current• Low thermal resistance



NXP’s NUR460P: page 3ON SEMI’s NCP125x: page 10PARTNERWORKING

NXP Semiconductors has released twoversions of an ultra-fast power diodefor use in applications requiring highinrush-current capability,thermal-cycling performanceand junction-temperaturecapability.

NXP’s ultra-fast rectifiersare designed to offer thebest trade-off between forwardvoltage and reverse-recovery time,helping to minimise power losses inboth the diode and any associatedMOSFET. The result is improved systempower efficiency in switched-mode powersupplies. The parts offer a cost-effectivealternative to the use of Schottky technology.

The new BYC20X-600P and BYC30X-600P,packaged in a SOD113 (two-lead TO-220F)plastic package, are rated for a maximumpeak forward current of 220A (8.3ms pulse ata junction temperature of 25°C). The typicalforward voltage of the parts is specified at 1.4V.

The devices are rated for a maximumjunction temperature of 150°C. Among theirother attractive features is a low 7.6A peakreverse-recovery current at a junctiontemperature of 125°C and 30A forward

current for the BYC30X. Reverserecovery time at these conditions isa typical 70ns.

Isolation is another strength ofthe two devices. The maximum

RMS isolation voltage forboth is specified at

2,500V. Isolationcapacitance from

cathode toexternal heat

sink is rated at atypical 10pF.



100V TrenchFETs boost energy efficiency, savePCB space

New ThunderFETs combine the latest silicon and package advancesfor increased performance and power density

VISHAY

APPLICATIONS• DC/DC converters• Full-bridge converters• Power bricks• Point-of-load converters

FEATURES• 100% Rg and UIS tested • Maximum continuous drain current @ 25°C:

• 6.3A (SiB456DK)• 11.3A (SiA416DJ)

• 20V maximum gate-source voltage• Typical gate charge:

• 1.8nC (SiB456DK)• 3.5nC (SiA416DJ)



The NCP1250 and NCP1251 feature innovative new technology to help implement over-power protection in low-cost converters.

The NCP1250 and NCP1251 from ONSemiconductor are current-modePWM-control ICs housed in tiny 6-pinpackages, which provideintegrated features allowingdesigners to build ruggedand efficient offline flybackpower supplies.

Both devices incorporateproprietary technology thatsimplifies the challenge ofimplementing Over-PowerProtection (OPP) in a powersupply that must also achievevery low no-load or standbyconsumption. This allowsdesigners to harness themaximum delivered power,without affecting standbyperformance, using only twoexternal resistors. A latched Over-Voltage Protection (OVP) iscombined on the same pin.

The NCP1251 has an additionalover-voltage protection monitoringthe supply-voltage (VCC) pin,

which automatically latches the device offwhen the voltage at the pin exceeds a certainlevel.

Each IC has a supply range up to 28V, andhosts a jittered 65kHz or 100kHz switchingcircuitry which helps to minimise EMIemissions. When the power on the secondary

side starts to decrease, the controllerautomatically folds back its switchingfrequency down to a minimum level of 26kHz.As the power demand reduces further, the partenters skip-cycle operation while limiting thepeak current.

ON SEMICONDUCTOR

APPLICATIONS• Offline adapters • Set-top boxes• AC-DC converters• Printers• Notebooks and netbooks

FEATURES• Internal ramp compensation• Frequency jittering from full load to skip-cycle• Latch input for OVP and OTP

implementations• Soft-start function• Compact TSOP-6 package



NXP’s NUR460P: page 3NXP’s BYC30X-600P: page 9PARTNERWORKING

Extending Vishay’s ThunderFET®

technology to smaller package sizes, theSiB456DK and SiA416DJ are theindustry’s first 100V N-channel TrenchFETpower MOSFETs offering low on-stateresistance down to hundreds ofmilliohms within footprint sizes of 2mm x2mm and less.

For applications requiring highest efficiency,the SiA416DJ, in the 2mm x 2mm PowerPAK®

SC-70 package, has maximum on-stateresistance of 83mΩ at 10V and 130mΩ at 4.5V,and low Figure of Merit (FOM) of 540mΩ-nC at10V and 45 mΩ-nC at 4.5V.

For applications where small size is morecritical, the SiB456DK is packaged as a 1.6mmx 1.6mm PowerPAK SC-75 device. It hasmaximum on-state resistance of 185mΩ at 10V

Innovative PWM controllers boost efficiencyand ruggedness

and 310mΩ at 4.5V, and FOM of 611mΩ-nCat 10V and 558mΩ-nC at 4.5V.

By specifying on-state resistance at 4.5V,these devices help simplify and shorten thetask of designing the gate-driver circuit.

Moreover, both package types are thermallyenhanced, featuring a large exposed undersidedrain connection for efficient heat dissipation,enabling high current-handling capability andoptimum reliability at high ambient operatingtemperatures.



Capacitive-touch controllersprovide energy-saving capability

Integrated features of the SX9510 and SX9511 save many externalcomponents

SEMTECH

Analogue mux/demux provides eight channels of I/ONXP SEMICONDUCTORS

The Semtech SX9510 and SX9511eight-channel capacitive-touchcontrollers provide an energy-efficientmeans to implement up to eight touchbuttons while driving up to eightindicator LEDs.

APPLICATIONS• LCD TVs and monitors• Domestic appliances• Consumer electronic products• Industrial or automotive instrumentation• Mechanical-button replacement

FEATURES• Core supply-voltage range: 2.7V to 5.5V • I/O supply-voltage range: 1.65V to 5.5V • Capacitance-offset compensation to 40pF• IR detector compatible with NEC, RC5,

RC6, Toshiba, RCA and others (SX9511)



APPLICATIONS• Automotive chassis and safety functions• Climate-control systems• Passenger-detection, pressure-sensing

systems• Steering systems• Windshield-wiper, humidity-sensing systems

FEATURES• Automotive product qualification in

accordance with AEC-Q100 (Grade 1)• Operating temperature: -40°C to 125°C• ESD protection:

• MIL-STD-883, method 3015 exceeds2000V

• HBM JESD22-A114F exceeds 2000V• MM JESD22-A115-A exceeds 200V

(C = 200pF, R = 0Ω) • Latch-up performance exceeds 100mA

JESD 78 Class II level A



Microchip’s PIC32MX1/MX2: page 3ON Semi’s LC717A00AJ: page 4PARTNERWORKING

Supply Voltage Typical On-state Resistance

2V 400Ω3V 250Ω3.3V 120Ω4.5V 76Ω6V 59Ω

The 74HC4851-Q100 and 74HCT4851-Q100 are notable fortheir low on-state resistance

NXP Semiconductors has introducednew analogue multiplexers/demultiplexers that can be used inautomotive designs to provideadditional I/O lines tomicrocontrollers.

The 74HC4851-Q100and 74HCT4851-Q100are eight-channelanalogue multiplexers/demultiplexers with threedigital Select inputs, anactive-low Enable input,eight independentinputs/outputs and a common input/output.With the Enable pin Low, one of the eightswitches is selected, in a low-impedance On state, by one of the digital inputs. With theEnable pin High, all switches are in the high-impedance Off state, independent of thedigital inputs.

The devices feature injection-current effectcontrol, a great benefit in automotiveapplications in which voltages in excess of thesupply voltage are common. The injection-current effect control allows signals at disabledanalogue input channels to exceed the supply

voltage without affecting the signalof the enabled analoguechannel. This eliminates theneed for externaldiode/resistor networkstypically used to keep theanalogue channel signalswithin the supply-voltagerange. The devices toleratea wide operating voltagerange of 2V to 6V.

The 74HC4851-Q100 and74HCT4851-Q100 are pin-compatible

with the 74HC4051 and 74HC4052 from NXP.

The devices draw just 600µA in normaloperation, and 330µA in sleep mode. Anintegrated IR decoder in both the SX9510 andSX9511 enables remote controls from many ofthe large consumer electronics manufacturersto wake these devices from standby.

Both the SX9510 and SX9511 provide eight15mA LED-driver outputs with support foruser-programmable intensity as well as blinkingand breathing modes. In addition, bothdevices have two analogue outputs, one ofwhich can drive a buzzer to provide audiblefeedback on button touches. The SX9510 alsooffers proximity sensing while in sleep mode.

Semtech’s patented circuitry allows all of thesefeatures to be integrated in a single device,saving board space and component count,simplifying design, and streamlining assembly.

The devices are able to operateautonomously, using pre-programmed buttonsensitivities and thresholds, LED intensities andblinking/breathing settings, with no external I2Ccommunication required. Whenever thecapacitance value changes, due either to aproximity detection or finger touch/release, thecontroller informs the host processor throughthe analogue outputs or an open-draininterrupt and an I2C register read.

No external dynamic programming is required,and the devices are able to adapt automaticallyto humidity and temperature changes tomaintain correct touch/no-touch response.

High-current connectors enhancereliability and safety


Hirose's latest high-power connectors feature innovations for enhancedsafety and reliability

The Hirose EM connector systemsatisfies growing demands for high-powered connectors offering advancedreliability for industrial equipment,comprising plugs and receptacles thathave the capacity to handle current up to50A and AC or DC voltages up to 500V.


The innovative connector design incorporatesthree 50A power contacts and one groundcontact making it suitable for use in three-phaseelectrical systems. The contacts are arrangedin sequence to ensure the ground contact isconnected before the power contacts duringthe mating process, thereby ensuring safetyduring mating and un-mating. A further benefitof the EM series is a special protective coverover the female contacts that minimisesexposure hence preventing damage.

Termination of the crimp contact is quickand easy using standard JIS crimping tools. Acontact-removal tool is also available. Theconnector housing features integrated hookswhich allow the receptacle to be mounted onto a 35mm DIN rail to offer design flexibility. Apanel-mount version is also available. Theconnector can withstand high mechanicalstress, including up to 200N of cable-pull forcewhen pulled vertically. The robust snap-on lockprovides secure mating with an audible tactileclick to confirm correct engagement.

It is possible to apply customised keyingarrangements to prevent mis-mating of multipleconnectors. Up to ten different keyingcombinations are possible through optional keys.

HIROSE

Chip resistors deliver high precision overwide resistance, power and size ranges

Four resistor families meet the needs of precision sensing and measurement applications

Precision surface-mount metal-film chipresistors from TE Connectivity™ (TE)satisfy demanding applications in sectorssuch as telecommunication, industrialand military, offering a choice of powerratings, tolerance and stability values,and packages down to 0201 case size.

Designers can choose from various powerratings relating to case sizes from 0201 to 2512.The RN73 series offers TCR options of5ppm/°C and 10ppm/°C, with tolerance downto 0.01%. Covering case sizes from 0402 to2512, power ratings are from 0.063W to 0.5W.

The RP73 series provides high powerratings of up to 1.0W in the 2512 case size. Itprovides TCR down to 5ppm/°C, tolerancesdown to 0.05%, and rated operating voltageup to 200V DC. For applications requiringhigher power ratings in small case sizes, theRP73P series can dissipate up to 0.166W inthe 0603 case size or up to 0.25W in the 0805case size.

TE CONNECTIVITY Based on nichrome thin-film technology withthree layers for very stable high-frequencyperformance, they are available withTemperature Coefficient of Resistance (TCR)down to 5ppm/°C and cover a wide range ofresistance values in the E96 and E24 value grids.

The CPF series is suitable for all applicationswhere close accuracy and stability areessential, such as in measurement, telemetryor sensing circuits. This series offers TCRdown to 15ppm/°C and tolerances to 0.1%.

APPLICATIONS• Industrial power-control boxes• Semiconductor manufacturing machines• Generators and back-up batteries• High-voltage motor drives• Industrial welding equipment

FEATURES• Clip-on attachment to DIN rail• Compatible with wire gauge up to 8 AWG• 90mm total mated-connector length• TÜV and UL safety certifications• 100 mating-cycles durability



APPLICATIONS• Communications• Instrumentation • Industrial controls• Medical

FEATURES• Temperature range: -55°C to 155°C• Climatic category: 55°C/125°C/55°C• 1000MΩ minimum dry insulation resistance



P.I.E.S E C T I O N

Series Size Power Rating Temperature Coefficient ofResistance (TCR) Tolerance Packaging

RN73

0402 0.063W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 50000603 0.063W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 50000805 0.1W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 50001206 0.125W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 50001210 0.2W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 50002010 0.25W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 40002512 0.5W 5,10ppm 0.01%, 0.05% & 0.1% 250, 1000, 4000

CPF

0201 0.03125W 25, 50ppm 0.5% & 1% 1000, 5000, 100000402 0.063W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 5000, 100000603 0.063W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 50000805 0.1W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 50001206 0.125W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 50001210 0.2W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 50002010 0.25W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 40002512 0.5W 15, 25, 50ppm 0.1%, 0.5% & 1% 1000, 4000

RP73

0402 0.063W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 50000603 0.1W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 50000805 0.125W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 50001206 0.25W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 50001210 0.3W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 50002010 0.5W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 40002512 1W 5, 10, 15, 25, 50ppm 0.05%, 0.1%, 0.5% & 1% 250, 1000, 4000

RP73P 0603 0.1666W 25, 50ppm 0.1%, 0.5% & 1% 250, 1000, 50000805 0.25W 25, 50ppm 0.1%, 0.5% & 1% 250, 1000, 5000

D E S I G N N O T E



AudioStreamer reference board provides flexible design template

The AudioStreamer Future-Blox board from Future Electronicsis a reference design that provides individual customersimplementing audio recording and playback systems with auseful design template that they can easily adapt andoptimise for their own application.

In fact, since the AudioStreamer solves some important problems foundin all audio system designs, it can substantially reduce the time it takesto implement a proof of concept or early prototype. In particular, theboard gives the design engineer a template for: • Component selection that balances audio performance and Bill-of-

Materials (BoM) cost• Board layout, minimising the effect of distortion and EMI• Support for a variety of audio protocols; MP3, FLAC, Ogg Vorbis and WAV

Each customer’s design will have a unique combination of requirementsin parameters such as Signal-to-Noise Ratio (SNR), BoM cost, audiocompression, input sources and so on. The AudioStreamer boardaccommodates a very wide range of design specifications by offering anon-board choice of components of varying capabilities. This enables thedesigner to experiment with different combinations of components tofind the best mix for their application.

For instance, for high-end Hi-Fi systems the AudioStreamer includesDACs which can achieve a figure for Total Harmonic Distortion andNoise (THD+N) of higher than 100dB. At the same time, the boardcontains lower-performance CODECs and DACs suitable for use inindustrial systems in which cost is of greater importance than audiofidelity, and in mid-range applications such as set-top boxes. Theboard’s flexibility is also in evidence in its support for audio data-inputsources including Ethernet, USB and various memory cards, as well asits provision of a variety of analogue and digital microphones suitable forrecording of speech.

In short, the AudioStreamer board is useful for designers of any audiodevice or embedded audio system, ranging from professional audioequipment to industrial applications such as public-announcementsystems.

System architectureThe core of the design is Freescale’s Kinetis MK60FN1M0VMD15, a150MHz ARM® Cortex™-M4 microcontroller, shown in Figure 1. Thishandles decompression of audio files, as well as data-packet receptionand management. The device’s advanced processor core can performthese functions with ease, leaving more than 75% of bandwidth availablefor the user application.

The microcontroller runs Freescale’s MQX™ real-time operating systemwhich is supplied free with Kinetis products. It interfaces to a TCP/IPstack for Ethernet connectivity via a Micrel KSZ8021RNL 10/100Ethernet physical layer transceiver. All software communications stacks,Ethernet and USB, are integrated into MQX and also supplied free.

The AudioStreamer board can handle the important audio formats inuse today. For high-fidelity and professional-audio applications, itsupports the lossless FLAC protocol. The familiar MP3 protocol used inmost music players is also available. The board also supports the OggVorbis format, an open-source protocol sometimes used in industrialapplications, as well as the WAV file type. The system can work at up to24-bit resolution and 192ksamples/s.

This, then, deals with the first determinant of sound quality: the typeand degree of audio compression. Clearly the components in the signalchain are also going to have a marked effect on the quality ofreproduction of the audio signal, no matter how compressed it is. Here,the AudioStreamer board provides the designer with a choice ofCODECs and DACs from Wolfson Microelectronics. For premiumperformance, the WM8741 DAC offers an SNR value of up to 128dB,and provides 24-bit and 192ksamples/s support.

A lower-cost option is available with the WM8904 CODEC, whichprovides an SNR of up to 96dB, while also supporting 24-bit and192ksamples/s operation. Finally, the WM8524 is a 24-bit DAC giving upto a 106dB SNR.

Complementing these high-quality conversion devices, the design ofthe board’s peripheral elements has been carefully crafted to minimisenoise and distortion. Key features of its implementation include the useof low-jitter clock sources throughout, and of low-noise capacitors fromNIC in the signal path and power supply. The power supply also benefitsfrom the use of ultra-low-noise regulators from Micrel.

Conceived as a development tool for design engineers, the AudioStreamer board is supplied with a PC-based GUI which allows theuser to select audio files for download to the board, set up sample audiofrequencies, and select the required replay channels, CODEC or DAC,and audio-data sources. The GUI also provides an easy means to usethe on-board analogue and digital microphones and replay recordingsfrom them.

The AudioStreamer board is available free to qualified customers ofFuture Electronics. Design engineers can apply to receive a board atwww.my-boardclub.com.

FUTURE ELECTRONICS

Fig. 1: The AudioStreamer from Future Electronics enables audio streaming for applications ranging fromlow-cost low-power embedded, to industrial PAs and professional audio equipment

EVALUATIONBOARDS AT my-boardclub.com

my-ftm.com/130224TO REQUESTA BROCHURE


A P P L I C AT I O N S P O T L I G H T – A U D I O T E C H N O L O G Y

Audio TechnologyOver the past five years, consumers have come to attach hugeimportance to the convenience, availability and portability oftheir music listening, across an ever-widening choice ofdevices. This in turn has led to massivechange in the choice of audio componentsavailable to design engineers, as componentmanufacturers devise innovative andinteresting ways for OEMs to meet consumers’demands.

This innovation in audio technology isreflected in this Application Spotlight. Forinstance, the demand for high-quality audio inconvenient portable devices is served by thelatest headphone amplifiers from Rohm. Usinga capacitor-less design, an architecture whichsaves weight, size and cost, the BD88200 andBD88400 succeed in producing a rich,powerful bass output, while using around halfas much power as competing devices.

Consumers now, of course, expect to be able to carry all theirmusic with them at all times, and to play it anywhere. This hasdriven a vibrant market for peripherals and docking stations forsmartphones and music players. Freescale has introduced a

helpful resource to help accelerate the design of such devices:its ‘Made for iPod’ Tower development board is also featured inthis Application Spotlight.

Likewise, the AudioStreamer developmentboard from Future Electronics helps designers toovercome the difficulties involved in a practicalimplementation of a digital audio streamingsystem by integrating many of the necessaryelements into a high-quality reference design.

As music has become easily portable, thelistening experience now takes place in allkinds of environments, including some, such astrains and train stations, aeroplanes andairports, that degrade audio quality. The AS3421and AS3422 active noise-cancellation ICs fromams solve this problem by providing high levelsof noise attenuation while consumingremarkably little power.

As ever, full support for these and every other devicefeatured in FTM is available through your local branch of FutureElectronics, while free development boards and kits areavailable to all qualifying customers of Future Electronics atwww.my-boardclub.com.

2x10W Class-D amplifiers allow choice ofdigital or PWM input

ON Semiconductor's Class-D amplifier IC portfolio provides flexibility to satisfy a wide variety of applications

ON Semiconductor’s LV4904V andLV4924VH are Class-D audio amplifiersfeaturing Bridge-Tied Load (BTL)output, and give designers the choiceof using either an I2S digital input inthe case of the LV4904V or a PWMinput with the LV4924VH power cell.

Both ICs are 10W 2-channel amplifiers offeringhigh efficiency and high audio performancewith low distortion. The LV4904V allowsdesigners to build an effective Class-D poweramplifier using a single chip plus a minimalnumber of external components. It provides asoft-mute function and a gain controller withzero pop noise. The device’s functionalsettings can be established through an I2C businterface, or alternatively can be set viaexternal pins without using the I2C bus. TheLV4904V features integrated under-voltage,

over-current andthermal protection,and has an extremelylow standby current of1µA.

The LV4924VHrequires a PWMmodulator in theprevious stage, andgenerates a high-quality audio outputfrom the PWM signalprovided. It has a low-power standby modedrawing a current of10µA. Housed in a36-pin HSSOPexposed-die packagethat provides goodthermal performance,

the LV4924VH is featured for optimumreliability in demanding audio power-amplifierapplications. Important features such asspeaker protection against DC offsets andover-current protection are built in, which helpsto simplify design and minimise demand forexternal components.

ON SEMICONDUCTOR

APPLICATIONS• Flat-panel televisions• Home audio equipment

FEATURES• LV4904V:

• Amplifier-stage voltage range: 8V to 20V

• 3.3V control logic• LV4924VH:

• Amplifier-stage voltage range: 9.0V to 20V

• 3.3V or 5V logic control• Built-in bootstrap diode• Warning output to CPU



High-performance audio amplifier minimises noiseand protects speakers

The tiny PAM8008 is ideal for portable applications

The PAM8008’s power-limit technologyautomatically removes any harsh clipping ofthe output signal in response to excessiveinput-signal fluctuation. This minimisesoutput distortion and protects the speakerfrom harm, even if the input is significantlyoverdriven.

In addition, an integrated noise-reductioncircuit achieving 6dB noise attenuation furtherimproves the amplifier’s sound quality.

DIODES INCORPORATEDAPPLICATIONS

• LCD monitors• Notebook or tablet PCs• Portable speakers• Portable DVD players• Game machines

FEATURES• Filterless output• Low pop-and-click noise• 95dB signal-to-noise ratio• -70dB Power-Supply Rejection Ratio

(PSRR)• Active-high Mute pin• Chip-enable pin




16 F R E E D E V E L O P M E N T K I T S AT W WW . M Y- B O A R D C L U B . C O M

Integrated headset-speaker driversimplement ambient-noise cancellation

The AS342x headset-speaker drivers allow Active Noise Cancellation for improvedaudio experiences, at a competitive price

ams has introduced two headset-speaker drivers featuring a fullyanalogue implementation of ActiveNoise Cancellation (ANC), and offeringvery low power consumption andsystem bill-of-materials cost.

ANC brings an enormous improvement to thelistener’s experience, but wireless-headsetmanufacturers have been deterred fromimplementing it previously because of cost,

AMS power, size and weight concerns. With theintroduction of the ultra low-power AS3421and AS3422, which provide an almostcompletely integrated solution for drivingBluetooth headsets, manufacturers will nowfind it viable to implement noise cancellation inwire-free headsets, headphones andearphones.

The new single-chip ANC speaker driversprocess external noise sensed by amicrophone embedded in the headset, andgenerate a noise-cancelling signal, whileamplifying the desired audio signal with verylow levels of distortion. They typically offerambient-noise reduction of more than 25dB.

The devices are optimised for use inwireless headsets, many of which useBluetooth to provide an RF channelbetween the host device and theheadset. Low power-consumption andlong battery life are particularlyimportant requirements in wirelessheadsets: the all-analogue design of theAS342x is markedly more efficient thanrival DSP-based digital speaker-driverICs. The AS3421 and AS3422 draw just7mA at 1.5V in stereo ANC mode, andbelow 1µA in quiescent mode. Theyalso implement an ultra low-powerANC-bypass mode when the userselects the playback-only function.

APPLICATIONS• Headphones• Earphones

FEATURES• Amplifier:

• 100dB signal-to-noise ratio• 0.1% total harmonic distortion at 32Ω • Click- and pop-less start-up and mode

switching • ANC function:

• Feed-forward noise cancellationdefinable with simple RC components

• Feed-back noise cancellation with filter-loop transfer function

• Simple in-production softwarecalibration




DETAILSON PAGE

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The PAM8008 stereo Class-D audioamplifier from Diodes Incorporatedprovides designers of low-voltageaudio systems with a simple, very lowdistortion solution. Capable ofoperation at up to 90% efficiency, thedevice can deliver an RMS outputpower of up to 2.4W per channel at 1%THD+N for a 4Ω load and 5V supply.

By helping to reduce any need for externalfiltering, this circuit saves board space andcomponent cost in 3.3V- or 5V-poweredsystems.

The PAM8008 saves additional externalcomponents by also integrating an advanced64-step DC volume-control function with awide adjustment range of -80dB to 20dB, aswell as auto-recovery short-circuit and over-temperature protection circuits. The PAM8008comes in a SO-16 package.

In addition, the parts offer fully differentialstereo line inputs to match the differential lineoutputs from typical Bluetooth-based headsetsystems-on-chip, reducing the requirement forexternal components.

The AS3421 is housed in a 4mm x 4mmQFN24 package while the AS3422 uses a5mm x 5mm QFN32 package.



Tower module supports rapid developmentof Made for iPod equipment

FREESCALE

NEED HELP WITH YOURAPPLE® PROJECT?FUTURE ELECTRONICSIS A LICENSED APPLEDEVELOPER

Audio power modules simplify design of Class-D amplifiers

High integration, heatsink-free design and high current/voltage headroom simplify design and maximise audio performance

The IR4301M and IR4302M modules integratean audio PWM controller and two powerMOSFETs optimised for audio applications in asingle package. The IR4301M is a single-channel version and the IR4302M is a dual-channel device. Designers can use thePowIRaudio modules to implement a Class-Damplifier with equivalent audio performance toClass-AB amplifiers while providing superiorefficiency in a smaller board area.

INTERNATIONAL RECTIFIER

The TWR-DOCK docking module providesaccess to the 30-pin connection used byApple devices to transfer analogue audio andvideo signals. It is equipped with standardRCA and S-Video connectors, supports digitalaudio streaming in both directions over USB,and provides for control of and communicationwith a wide variety of peripheral devices.

The TWR-DOCK module may be used withthe wide range of microcontroller,microprocessor, sensor and communicationmodules available today as part of the FreescaleTower System.

It is expected that the TWR-DOCK will beused in the development of iPod, iPhone andiPad media accessories such as audio dockingstations. But it can also be used in app-drivenequipment, such as personal electro-

cardiogramstations, in whichthe iPhone oriPad provides adisplay andprocessing hostfor a sensor-based peripheraldevice.

Demonstrationsoftware availablewith TWR-DOCKshows simpleiPod controlfunctions, controlfunctions with a graphical user interface, host-mode digital audio streaming over USB, anapp-based electro-cardiogram, and an app-based altimeter.

A ‘Made For iPod’ (MFi) licence is requiredto develop MFi accessories, and the TWR-DOCK and associated software anddocumentation are only available to licenseeson Apple’s MFi Portal at;https://developer.apple.com/programs/mfi/.Add-on versions are also available whichinclude the Kinetis K60 microcontroller moduleas well as sensor and graphics LCD peripheralmodules.

APPLICATIONS• iPod, iPhone and iPad docking equipment

FEATURES• 30-pin docking connector• USB Type A receptacle for USB-to-30-pin

connection cable• 3A power supply and connector for iOS

device charging• Analogue stereo audio line out (RCA)• Analogue video out supporting composite,

component and S-Video • Digital audio input and output streaming to

iPod, iPhone and iPad devices via USBconnection



APPLICATIONS• Home theatre systems• Car audio amplifiers• Docking stations• PC audio systems• Musical instruments

FEATURES• High peak music power output• Differential or single-ended input• Start and stop click noise reduction• High noise immunity




DETAILSON PAGE

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DETAILSON PAGE

19

Freescale has introduced a newmodule that enables users of its TowerSystem boards to rapidly developelectronic accessories and peripheralequipment for Apple iPod®, iPhone®

and iPad® devices.

The new PowIRaudio™ family ofintegrated power modules fromInternational Rectifier provides designerswith a simple way to implement a high-performance Class-D audio amplifierdesign. Circuits using PowIRaudiomodules will also benefit from a reducedcomponent count and a smaller boardfootprint compared to today’s Class-Damplifier designs.

Part Number Number ofChannels

Power SupplyVoltage

Peak Output Power(RMS per Channel) Package

IR4301MPbF 1 80V or ±40V 130W PQFN 5mm x 6mm

IR4302MPbF 2 80V or ±40V 70W PQFN 7mm x 7mm

A number of protection and monitoringfeatures are common to both devices, includingover-current protection, thermal shut-downand internal/external shut-down. The IR4302Malso offers clip detection.

A range of reference designs are availablethrough Future Electronics to help in thedevelopment of audio systems.

The modules are notable for their high audioquality: a typical figure for total harmonicdistortion and noise is 0.02%, for a 1kHz, 1Woutput into a 4Ω load. Highly efficient, theyoperate without a mechanical heatsink over awide power-supply range on either a single orsplit power supply.

High voltage ratings and noise immunityensure reliable operation in various environmentalconditions. Because the modules are availablein single- and dual-channel versions, designerscan easily make multiple stereo amplifiers withdifferent channel configurations while usingcommon circuit-design elements.


DETAILSON PAGE

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Capacitor-less headphone amplifiers produce rich bass output

Low circuit current, low distortion and low component count deliver market advantage for headphones using Rohm'sBD88200 and BD88400

Rohm Semiconductor has introducedtwo families of high-performanceheadphone amplifiers that offer anunusual combination of low current andvery low distortion, providing bothexcellent sound quality and low powerconsumption.

Headphone amplifiers usually suffer from atrade-off between supply current anddistortion. But in the BD88200 and BD88400

ROHM SEMICONDUCTOR

APPLICATIONS• Portable audio players• Digital cameras• Voice recorders• Bluetooth headsets

FEATURES• Virtual ground-referenced outputs for

noise reduction (BD882xx only)• Operating voltage: 2.4 to 5.5V• Short-circuit and thermal-overload

protections





Hybrid audio amplifiers reduce designcomplexity and board space

ON Semiconductor has expanded itsaudio-amplifier portfolio with the additionof the STK433-040N-E, STK433-060N-Eand STK433-130N-E Class-AB, two-channel audio power-amplifier hybridmodules.

These devices consist of a pre-driver, powertransistors and general peripheral functionsintegrated into a single package. The partsoffer considerable savings in terms of boardspace and in the design effort required toimplement a complex Class-AB amplifier.

The new parts offer low-power operation,drawing just 1mA in stand-by mode.Quiescent current at no load is 30mA for theSTK433-040/060N-E and 80mA for the STK433-130N-E.

These range from low-power, below 1W,Class-AB amplifiers through to 1-5W, 10-20Wand above 20W Class-AB amplifiers, and toClass-D amplifiers rated for outputs as low as1.4W and as high as 20W.

ON SEMICONDUCTOR

APPLICATIONS• Consumer audio amplifiers• Home theatre systems • Set-top boxes• Gaming machines

FEATURES• Pin-to-pin interchangeable modules

ranging from 40W to 150W • Simple external circuitry can be used to

implement stand-by and mute functions• Easy-to-implement external short-circuit

protection


my-ftm.com/130231FOR PARTS ANDLATEST PRICINGPart Number Output (10%/1kHz) VCC Max. (6Ω) Size

STK433-040N-E 40W x 2 Channel ±36V (W) 47mm x (H) 25.6mmSTK433-060N-E 50W x 2 Channel ±40V (W) 47mm x (H) 25.6mmSTK433-130N-E 150W x 2 Channel ±63V (W) 67mm x (H) 25.6mm

families, Rohm has implemented a uniquecircuit structure that offers low distortion andlow circuit current at the same time. Totalharmonic distortion and noise is typically0.006% at a 10mW output, while the supplycurrent is just 2mA, roughly half the value ofconventional amplifiers.

Another valuable feature of the BD88xxxdevices is their capacitor-less design. Theheadphone amplifiers integrate a stablenegative power-supply charge-pump circuit. Inaddition, signal processing is performed atground reference, and this eliminates the needfor an output coupling capacitor and allowsdirect connection to the headphones. Thisenables attenuated, powerful bass playback

similar to conventional systems that use anoutput coupling capacitor.

The BD88200 and BD88400 amplifiers areproduced in an ultra-compact 2.1mm x2.1mm WLCSP package, reducing mountingarea to only one-fifth the size of conventionalcircuits using an 8-pin headphone amplifierand two large electrolytic capacitors. Theamplifiers also have a low profile, making themsuitable for space-constrained and portableapplications.

Typical total harmonic distortion for the STK433-040/060N-E is 0.02% at a 5W output, and0.01% for the STK433-130N-E.

The devices also offer an allowable load-shorted time of 0.3s.

The introduction of the STK433-040N-E,STK433-060N-E and STK433-130N-Eextends ON Semiconductor’s portfolio of audioamplifiers, which includes a very wide range ofboth Class-AB and Class-D devices.

Board of the Month

The IRAUDAMP19 reference design boardfrom International Rectifier is a two-channel,75W/channel half-bridge Class-D audio poweramplifier with a single power supply.

This reference design demonstrates how touse the IR4301M, a PowIRaudio integratedClass-D power module, with a single powersupply, including implementing protectioncircuits, and optimising the PCB layout. Itachieves a Total Harmonic Distortion andNoise (THD+N) figure of 10% at a 4Ω load and75W output. THD+N is 0.02% if output poweris reduced to 10W.

The single-channel IR4301M module used inthe IRAUDAMP19 integrates in a single packagean audio PWM controller and two powerMOSFETs optimised for audio applications. Inthis reference design, it does not require anadditional heatsink or fan cooling for normaloperation at one-eighth of continuous ratedpower. The design provides all the requiredhousekeeping power supplies for ease of use.This two-channel design is scalable for powerand for the number of channels.

MicrochipThe PIC32 MX1/MX2 starter kit sa complete solution for exploringthe low-cost, high-performancePIC32MX1/MX2 devices.This kit is perfect for development ofbasic user interfaces with mTouchTM

buttons and high quality audio. The boardis pre-loaded with demo code for anaudio player. Download the free MPLABIDE and the demo code source from theweb to jump start your development.Board References:USB Starter kit DM320003-2Ethernet Starter kit DM320004Wi-FI starter kit DV102411 Response Number: 03

amsActive Noise CancellationANC evaluation kits from ams allow forthe rapid prototyping of ANC-enabledheadsets, supporting mono/stereo,wired/wireless and feed-forward/feedbacktopologies. Kits can also be combined tocreate hybrid prototypes. The kits areaccompanied by an easy to use GUI andthe necessary interface hardware toconnect to the USB port of a PC. Board References:AS3421-EK-STAS3422-EK-ST Response Number: 27

New digital audio development board letsdesigners experiment with a choice of audio file

formats and DACs

FreescaleRapid development of Made foriPod equipment

The TWR-DOCK docking moduleprovides access to the 30-pin connectionused by Apple devices to transferanalogue audio and video signals. Board Reference:TWR-DOCK Response Number: 28

ON SemiconductorAudio amplificationBoard Reference:STK433-040NGEVB Response Number: 31

my-boardclub.com classifieds

Future Electronics’ Board Club: supporting innovative electronics designEurope’s electronics industry thrives on the application of innovation and creativity, and anessential innovator’s tool in design projects is the development board. The Board Club website is aFuture Electronics resource for users of development boards. Here, and only here, Board Clubmembers can gain access to exclusive free development boards and development board offers.If you would like to register for membership, please visit: www.my-boardclub.com/register.php

To apply for these free boards go to: www.my-boardclub.com/ftmTerms and conditions apply. Visit www.my-boardclub.com/about_us for details

D E V E L O P M E N T B O A R D S I N T H I S I S S U E

19

APPLICATIONS• AV receivers • Home theatre systems • Mini-component stereos • Powered speakers • Sub-woofers • Musical instrument amplifiers • Car audio amplifiers

FEATURES• PWM modulator: self-oscillating, half-

bridge topology• 230µV residual noise• Over-current protection• High- and low-side over-voltage and

over-temperature protection • Under-voltage protection

Reference board demonstrates use of integratedClass-D amplifier module

International Rectifiers’ IRAUDAMP19 reference design board


Quicker development of digital audio equipment, from hi-fi quality to low-cost,low-power embedded or industrial audio, is now possible with the introduction ofthe new AudioStreamer Micro-Blox development board from Future Electronics.

The new development board features an ARM® Cortex™-M4 microcontroller withaudio file decompression software, a choice of high-end and low-cost DACs, aCODEC, and digital and analogue microphones. By using the board’s free PC-based graphical user interface, which connects to the board via USB, developerscan start recording and playing back audio files in minutes.

Read more about AudioStreamer on page 13.Available at: www.my-boardclub.com

APPLICATIONS• Digital audio streaming equipment• Embedded and industrial audio• Hi-Fi

FEATURES• High-end WM8741 DAC for

playback of FLAC files• Low-cost WM8524 DAC for

playback of compressed audio files• Small, efficient on-board power

supply • Three 3.5mm stereo sockets • WM8904 ultra low-power CODEC• Two digital microphones and one

analogue microphoneAudioStreamer board decodes FLAC, WAV, MP3and Ogg Vorbis files

By Marco CentassoFAE, Future Electronics

T E C H N I C A L V I E W


RF transmitters for low-cost remote controls are typically builtwith a Colpitts-oscillator circuit comprising a SurfaceAcoustic-Wave (SAW) resonator and a transistor for simplicityand economy. As incoming EU regulations limiting out-of-band RF emissions effectively make this approach unviable,Marco Centasso, FAE for Future Electronics, Italy, examineshow competitively priced RF-transmitter ICs can provide asuitable alternative.

In the residential sector, RF remote controls are most commonly found inapplications that can broadly be described as ‘home automation’: forinstance, for opening security gates, for switching and dimming lightingarrays, or for opening and closing garage doors. In these systems theRF remote control is strategically important, since it adds value bymaking the end-product easy to use and convenient whilst beinginexpensive for the manufacturer to make.

This kind of RF transmitter for remote controls has typically been builtwith a combination of an 8-bit microcontroller and a simple Colpitts-oscillator circuit made up of a Surface Acoustic Wave (SAW) resonatorand a transistor, as shown in Figure 1.

Built from a small number of inexpensive discrete components, Colpitts-oscillator circuits (named after their inventor, American engineer EdwinColpitts) have a very low Bill-of-Materials (BoM) cost and can operatefrom a low supply voltage.

Some drawbacks, however, include calibration difficulties owing to thecapacitive and inductive couplings generated by the tracks of the circuitboard. These can cause unwanted variances in the frequency of thecircuit between one production unit and another. Successfulimplementation of a PCB containing a Colpitts circuit therefore requiresthe careful attention of a skilled RF-board designer.

A second, but equally important, issue is the SAW resonator. Theequivalent model of a SAW resonator is an LC circuit, shown in Figure 2.

When a data frame must be transmitted at theinput of the SAW resonator there are voltagepulses. These pulses, or voltage peaks, acrossthe LC components emit harmonic signals atvarious multiples of the carrier frequency. From2013 new European EN 300 220 regulationscovering remote controls for residentialapplications considerably tighten the limits onout-of-band emissions, which effectivelymitigates against the use of conventional SAWresonators.

It is possible to implement a design using aColpitts circuit which meets the emissionsstandards, using more expensive narrowbandSAW resonators combined with a filteringcircuit. This complicates the circuit design andalso increases BoM cost.

RF remote-control designers must thereforefind a different solution that falls within theexisting BoM budget and also complies with thenew European regulations.

Low-cost ICs to the rescue?Until recently, the cost of an IC-based solution compared to a Colpittsoscillator circuit was so great as to be commercially unviable in the mostcost-sensitive applications. However, as semiconductor technology hasadvanced, short-range RF transmitters are now available at prices thatare competitive with the cost of a Colpitts circuit, at around €0.30 to€0.40, even before it is modified with additional components tosuppress unwanted RF emissions.

Since the RF-transmitter IC operates without a SAW resonator, out-of-band emissions fall within the new 2013 EU limits. In addition the highlyintegrated design is simple to implement, requiring far fewercomponents than a Colpitts-oscillator circuit.

Criteria for discriminating between short-range RF transmitter ICsAs a minimum requirement, a transmitter IC must support the Europeanlicense-free frequency bands of 434MHz and 868MHz. It is even betterif it covers the global license-free range of 315MHz to 915MHz,because this enables a manufacturer to market a single design on aglobal basis.

The mark of a high-quality transmitter is the ability to minimise thepower consumption of the remote control while delivering sufficientoutput RF power to support the required transmission distance. Anoutput value of 10dBm is desirable in residential applications, which isequivalent to a range of up to 150 metres in free space.

An example of a transmitter which combines suitable RF performancewith low power usage is the Semtech SX1243, as shown in Figure 3.

RF-transmitter design for dom controls meeting 2013 emissi

READ THIS TO FIND OUT ABOUT

• The impact of European EN 300 220 emissions regulations on RFremote controls

• Design challenges associated with conventional discretetransmitters

• Low-cost transmitter ICs from leading semiconductor manufacturers

Fig. 1: Colpitts-oscillator circuit

Fig. 2: LC oscillator equivalentto a SAW resonator

Fig. 3: Application circuit implementing OOK modulation with the SX1243 RF transmitter

Fig. 4: Application circuit implementing OOK modulation with the MLX72033 RF transmitter




estic remote ons limits

This is a 310MHz to 928MHz transmitter offering FSK/OOK modulationand a supply-voltage range of 1.8V to 3.7V. At a supply-current range of10mA to 17.5mA, the SX1243 delivers output power of 10dBm. Byusing this device, system designers can comply with the European EN300 220 standard, while contributing only around €0.45 to the BoMbudget, for 100,000 pieces a year.

An alternative, is the Melexis MLX72033 dual-band, 434MHz or 868MHz,transmitter suitable for operation in Europe, shown in Figure 4. It offers FSK and ASK/OOK modulation, and a supply-voltage range of2.1V to 5.5V. Its supply current ranges from 3.5mA to 22mA, and theoutput power is adjustable from -12dBm to 14dBm. It carries a typicalcost of €0.37, for 100,000 pieces a year.

Whichever transmitter IC is chosen, the designer of a remote controlwill benefit not only from built-in compliance with EN 300 220 and asimple circuit implementation, but also from the documentation andsupport materials provided by the IC manufacturer. The case for movingdesigns beyond the venerable Colpitts-oscillator circuit in this applicationhas never been stronger.

By Richard ParkerFAE (High-end Products), Future Electronics

READ THIS TO FIND OUT ABOUT

• Image-processing functions used in machine-vision systems• Open-source and proprietary software options• Evaluating embedded processors for image-processing tasks



New hardware and software choicesfor embedded computer vision

As computer vision is set to become a required function inmany applications, even those that currently contain nocamera at all, Richard Parker, FAE (High-End Products) forFuture Electronics, UK & Ireland, discusses improvements inimage-processing devices that simplify the design of camerascapable of supporting the required functionality.

Computer vision offers enormous opportunities to create value throughsystems that are capable of making useful decisions about real physicalobjects and scenes based on sensed images. Two high-profile examplesare Automatic Number-Plate Recognition (ANPR) used in securitysystems, and in-vehicle cameras that can monitor the length of time thedriver’s eyes are closed and sound an alert if they detect that the drivermight be asleep.

Embedded designers implementing computer vision are, of course,constrained by familiar issues such as cost, size, power anddevelopment time. Fortunately, recent improvements in the feature setsand performance of processors with image-processing capability, as wellas the emergence of open-source image-processing software accessibleto any OEM, significantly enhance the engineer’s ability to work withinthese constraints.

Key image-processing functionsAn intelligent camera for example, in a system which can pick out ahuman face in a scene, must be capable of recognising shapes, lines,edges and colours, and synthesising the information into a data setwhich enables it to decide that a given area in an image is a face.

This complex processing of image data can be accomplished byimplementing a small number of standard functions from the toolbox ofthe computer-vision programmer.

These functions operate as cascaded digital filters: the output of onefilter is fed into the input of the next. The type, order and parameters ofthese filters define what the algorithm does. Compared to audio filtersthat operate on 1-dimensional (1D) data, the algorithms in videoapplications operate on 2D data. Hence the complexity of video filters ismarkedly greater.

There are broadly five categories of image processing functions: colour-space conversion, binary morphology, image-transform filters, featuredetection and face/shape detectors.• Colour-space conversion (pre-processing): this takes an image and

converts it into a more useable form, for instance converting an RGBimage into a greyscale image. Often a raw image is not suitable fordirect processing and may require re-sampling or contrastenhancement.

• Binary morphology: comprises five important sub-functions. Thesesub-functions dilate the buffer, erode the buffer, open the buffer, closethe buffer and implement a threshold. Essentially binary morphologytakes the original image and passes a known structured element suchas a circle or square across the image matrix and performs a binary

function such as AND across the image. Dilation works on backgroundpixels. The centre of the structured element is centred on thebackground pixel of interest. If any of the pixels in the structured imagecorrespond to a foreground pixel then the background pixel is set to aforeground value. This has the effect of widening the foreground pixels.It can be used when a picture has elements that are missing in itsstructure. Erosion is essentially the opposite of this.

• Image-transform filters: include convolution, a way to implementboth high- and low-pass filters, and Hough transforms, which are usedin the detection of simple shapes such as straight lines and circles.

• Feature detection: includes functions such as edge detection, cornerdetection and blob detection. There are several algorithms associatedwith edge detection including the Sobel filter and the Prewitt filter. TheSobel filter works by convolving the image with 3x3 kernel matrices.By using the same kernel and then rotating this by 90° and producinga second result, the direction and intensity of the change in the imageis produced. This gives a change in the image gradient, thus definingthe edges of objects within that image.

• Face detection: a widely used algorithm for face detection is Viola-Jones, published by Paul Viola and Michael Jones in 2001.

Software-based image processingIn the past, electronics OEMs would need to have developed proprietarysoftware to implement the important image-processing functions.

This field of electronics design has been boosted in recent years,however, by the emergence of OpenCV (opencv.willowgarage.com), anopen-source library of computer-vision software which can be cross-compiled onto a variety of processor platforms. Compiled code can berun on widely-used operating systems such as Linux, Windows®, iOS orAndroid, providing APIs for image capture, image manipulation andvarious filtering algorithms.

More than 2,500 functions for computer vision are organised into anumber of categories, as shown in Figure 1. The latest version of thesoftware, v2.4, was released in May 2012. One important factor thatembedded developers need to be aware of is that OpenCV is platform-neutral, and aims to support PC-based applications as much asembedded systems. It does not, therefore, necessarily cater for typicalrequirements of embedded systems, such as code density andminimised memory footprint. In addition, the data formatting in OpenCVhas not been designed to be written and read by a DMA engine, whichcould be an advantage in some embedded systems.

Fig. 1: The OpenCV software suite offers a number of different categories of image-processing functions



Among proprietary alternatives, CogniVue, the manufacturer of image-cognition processors, provides a library of functions for its CV220xdevices. These are offered as image-manipulation primitives accessiblethrough a simple API in C code. The library has been designed to matcha port of OpenCV as closely as possible, providing a subset of theOpenCV functions, with a different API and optimised for specificCogniVue devices.

The CogniVue library’s functions include:• Image-memory and manipulation operations, such as copy, logical

operations and threshold operations• Colour-space conversion• Statistical functions such as mean value and histogram functions• Image filtering such as Sobel filters, Laplace filters and morphological

filters• Image-feature detection, such as Prewitt edge detection• Feature and object tracking, such as Harris corner detection, Good

Features To Track (GFTT), and optical flow (block matching)

New hardware choicesRunning software such as OpenCV is a compute-intensive task that canchallenge the tight constraints of size, power and bill-of-materials costthat typically face embedded-systems designers. The choice ofprocessor is therefore crucial to the success of the design.

There are considerable advantages to choosing media-optimisedARM®-based processors. First, ARM cores offer an outstandingpower/performance ratio. Second, processors with specific media-processing features help to improve performance, simplify designimplementation and save space. Both the processor families discussedin the following sections offer on-board CMOS image-sensor interfaces,and can be accommodated in a small camera module.

The Freescale i.MX53 processors implement a single ARM Cortex™-A8core and are optimised for multimedia applications, see Figure 2.

Board-support packages provided by Freescale, running on a low-costevaluation board, enable the use of operating systems including Android,Linux and Windows CE.

In the i.MX53 family, the A8 core runs at 1GHz, or 800MHz in theindustrial and automotive-qualified versions, and DDR2/3 memory at400MHz is supported. The devices offer two camera interfaces with a20-bit parallel interface and a total bandwidth of 3Mpixels at 15frames/s, giving a total throughput of 45Mpixels/s.


The i.MX53 processors offer strong multimedia and graphics capabilities.They include optimised blocks for the OpenGL ES2.0 graphics library(www.opengl.org), a widely used 2D and 3D graphics API, andOpenVG1.1 (www.khronos.org/openvg), which is a royalty-free, cross-platform API for hardware-accelerated two-dimensional vector and rastergraphics. Design support for computer-vision system developers isavailable through www.imxcommunity.org, Freescale’s i.MX forum site.

Freescale has also licensed CogniVue’s ‘Image Cognition Processing’IP for use in automotive applications. This means that devices such asthe i.MX53 will be able to run CogniVue software for advanced driver-assistance systems.

The i.MX53 processor’s display driver enables images to be directlydisplayed on a local LCD, or output to an external display via LVDS orVGA outputs. Outputs can also be sent via Ethernet to a main computeron a network. This would be suitable for a distributed system of multiplecameras, in which image processing is performed locally but a centralcontroller makes decisions based on multiple camera inputs.

Equally, the i.MX53 can operate as an integrated image processor andcontroller, making decisions based on the image-processing outputs andcontrolling industrial equipment via its CAN port.

Even more closely tied to computer-vision applications is the CogniVueCV220x family of image-cognition processors, shown in Figure 3.

The CV220x architecture features a 350MHz ARM9 processor runninghousekeeping and allocationfunctions, and a separate APEXcore to perform image-processing operations. TheAPEX block is central to thepart’s high performance, andcomprises an array of 96processing elements running inparallel, each supported by 3kBof local memory, and running atup to 180MHz. This parallelarchitecture allows very low-power operation.

The CV2201 features128Mbits, 16MB, of stackedDRAM. This makes for a simplehardware implementation,

offering low power consumption and a small footprint. The part containsa video DAC which can drive NTSC and PAL TV signals directly. Theparts available today offer interfaces through USB and low-speed serialports, supporting operation primarily as a local device. Parts supportingEthernet connectivity enable implementation in networked controlsystems.

CogniVue provides two evaluationkits for the CV220x: the referencedevelopment kit is a comprehensivedevelopment system offering access toall interfaces. A lower-cost alternativefor evaluation is the CV2201 PrototypeDesign Kit (PDK), the camera moduleis shown in Figure 4. This cameramodule can be programmed via theUSB port using pre-optimised orcustomer-developed libraries from theCogniVue software developer kit. Itoutputs an NTSC analogue signal.

ConclusionBy combining an optimised processor with off-the-shelf image-processingsoftware, it is now possible to implement computer vision within tightpower, cost and size constraints. Developers basing new computer-vision designs on the i.MX53 or CV220x device families will benefit fromhigh image-processing performance and a high level of integration aswell as built-in support for graphics and image-processing software.

Fig. 2: Block diagram of i.MX53xC processors, a part of the i.MX53 family optimised for industrial applications

Fig. 3: Block diagram of the CV220x family of imagecognition processors

Fig. 4: The CV2201 PDK camera module

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