power management · digital gas sensor offers low power consumption cambridge cmos sensors (ccs)...

Design Notes: pages 7-9 How does a MOSFET turn on? And the keyparameters to evaluate when choosing an LDO

Component Focus: pages 3-6 ON Semiconductor’s LC823450 audio-processingSoC helps to reduce development costs

Circuit Centre: pages 11-15 The best components for a new brushless DCmotor design

Application Spotlight: pages 16-24 New VIPer0P AC-DC converter consumes almostzero power when in Stand-by mode

Technical View: pages 26-27 How the use of higher-cost SiC powercomponents can reduce total system costs

Application Spotlight onEnergy, Power andPower Management

NEW IN THIS ISSUE

Developing a BLDCmotor-control system?

Turn to page 11 now to see thenew Circuit Centre feature!

I N T R O D U C T I O N

2 EMAIL [email protected] FOR SAMPLES AND DATASHEETS

The special theme of this issue is ‘Power and Power Management’, a topic ofinterest to anyone designing an electronics system. In the Application Spotlightsection of the magazine in particular, pages 16-24, readers will find a selection ofthe newest and best parts for power systems.

Many of these parts address system designers’need to reduce the amount of power that theirproducts consume, both in normal operationand when idle. Across every sector of theelectronics industry, the requirements of energy-efficiency legislation are becoming more stringent.

This is nowhere more so than in the field ofmotor drives: driven by regulations such as theEuropean Commission’s Energy-relatedProducts (ErP) directive, manufacturers ofelectric motors are having to equip theirproducts with the ability to match their speedand power output to the load, providing for ahuge reduction in average power consumption.

For many OEMs, the best way to meet therequirements of the ErP directive is to replacelegacy fixed-speed motors with a new VariableSpeed Drive (VSD) design. The Circuit Centresection on pages 11-15 is dedicated tocomponents that are ideal for use in VSDs.

This includes Intelligent Power Modules(IPMs) such as the ON Semiconductor deviceon page 15: IPMs provide a quick and simplemeans to implement a motor-drive’s inverter,and they also save board space whencompared to discrete inverter circuits.

The push for greater power efficiency is alsofuelling growing interest in Silicon Carbide (SiC)components: SiC devices achieve lower powerlosses than silicon-based equivalents, canswitch faster and can operate at highertemperatures. In terms of performance andefficiency, then, SiC is far better than silicon as amaterial for high-voltage power components.

Welcome to the first issue in 2016 of FTM, the technology magazine for customers ofFuture Electronics.

MikroElektronika signsdistribution agreement withFuture ElectronicsMikroElektronika, which manufactures arange of development tools and compilersfor microcontrollers, has announced adistribution agreement with FutureElectronics. Its Click boards support a widevariety of sensors, communication standardsand user interfaces, allowing engineers toeasily make design prototypes, while linkingmultiple boards with the mikroBUS™

interface standard. Tools are available for thePIC® and dsPIC® series from Microchip, theAVR® range from Atmel, the PSoC® devicesfrom Cypress Semiconductor and theSTM32 line from STMicroelectronics.

‘With Future Electronics as our partner,the availability of our products will increasesignificantly,’ said Tiziano Galizia,MikroElektronika’s Head of Sales.

ON Semiconductor to acquireFairchild SemiconductorON Semiconductor and FairchildSemiconductor International Inc haveannounced that they have entered into adefinitive agreement for ON Semiconductorto acquire Fairchild in an all-cash transactionvalued at approximately $2.4bn. Theacquisition creates a leader in the powersemiconductor market with combinedrevenue of approximately $5bn, diversifiedacross multiple markets with a strategic focuson automotive, industrial and smartphoneend markets.

Future Electronics is a franchiseddistributor worldwide for both companies.

‘Better demand managementneeded’ in electronics supplychain, Future Electronicsconference is toldOEMs need to improve the way they managetheir demand for electronic components ifthey are to handle the risks inherent in anincreasingly complex supply chain, AlbertoDella Chiesa, Vice-President for SupplyChain Solutions at STMicroelectronics told aconference hosted by Future Electronics inLeipzig on 12 November.

Some 150 customers of Future Electronicsfrom all over Europe attended the conference,which was dedicated to the theme of‘Supply Chain Innovation’. It also includedvisits to Future Electronics’ EMEA DistributionCentre (EMEA DC), one of Europe’s largeststores of electronic components, and to thelargest DHL logistics hub in the world, onthe site of Leipzig airport.

©Copyright 2016 Future Electronics Ltd. All trademarks contained herein are theproperty of their respective owners. Applications for product samples, badgeboards, demonstration boards, Future Electronics’ boards and other advertisedmaterials from Future Electronics are offered subject to qualification.

N E W S I N B R I E F

For more information [email protected]:

The problem with SiC is its cost – but theremight be good news on the horizon fordesigners who want to use SiC componentsbut who are concerned about the impact ontheir budget. As the market for electric andplug-in hybrid electric vehicles undergoes rapidgrowth, SiC components will be used in thevehicle’s traction power system and in fastchargers This promises to drive up salesvolumes and therefore to reduce unit prices.

This could have a knock-on effect on thegeneral electronics market, allowing a far widerrange of high-voltage applications to benefitfrom the efficiency and performance of SiCMOSFETs, diodes and power modules. TheBSM180D12P3C007, a SiC power module fromROHM Semiconductor featured on page 18, isan excellent example of the latest generation ofSiC power components now available to theelectronics industry.

Whether your interest is in SiC MOSFETs,IPMs or other new components, FTM presentsyou with an interesting selection of new parts.Enjoy reading!

Paul DonaldsonVertical Markets Director, Future Electronics (EMEA)

S T A R P R O D U C T

3VISIT THE ONLINE FTM MAGAZINE AT: WWW.My-FTM.COM

Industry’s lowest-power ARM Cortex-A5-based MPU featureshigh-grade security capabilities

Atmel’s SAMA5D2: ARM Cortex-A5 core runs at 500MHz

Atmel has launched a new series ofsecure Atmel | SMART ARM® Cortex®-A5-based microprocessors which offer lowerpower consumption than any other MPUin its class.

The new SAMA5D2 MPUs draw less than200µA in Retention mode with contextpreserved and have a fast 30µs wake-up time.In the devices’ new Back-up mode, in whichthe DDR memory continues to refresh itself, thecurrent is just 50µA.

The SAMA5D2 series provides for a highlevel of system integration, with the addition ofa complete audio sub-system and built-inPayment Card Industry (PCI)-level security inminiature Ball Grid Array (BGA) packages with196, 256 or 289 pins.

The series is ideal for applications requiringan entry-level MPU and an extended industrialambient temperature range of -40°C to 105°C.The new devices also provide an excellentupgrade option for designers currently usingARM926-based MPUs, and who require higherperformance, low-power operation, highersecurity, DDR3 support and a smaller footprint, aswell as access to audio and USB functionalityand Atmel’s patented SleepWalking™ technology.

The robust security system in the new SAMA5D2MPUs includes the ARM® TrustZone® technology,along with secure boot, hardware cryptography,RSA/ECC capability, on-the-fly encryption/decryption on DDR and QSPI memories, tamperresistance, memory scrambling, independentwatchdog, temperature, voltage and frequencymonitoring and a unique ID in each device.

Featuring an ARM NEON™ engine, the newSAMA5D2 series’ ARM Cortex-A5 core runs atan operating frequency of 500MHz, providingthroughput of 785DMIPS. Its memory systemincludes a configurable 16- or 32-bit DDRinterface controller, 16-bit External BusInterface (EBI), QSPI Flash interface, ROM withsecure and non-secure boot solution,128kbytes of SRAM, plus 128kbytes of L2cache configurable as an SRAM extension.

The user interface system for the SAMA5D2includes a 24-bit TFT LCD controller, multipleI2S and SSC/TDM channels, a stereo Class Damplifier and digital microphone support.

Ultra low-power op amps ideal for conditioning PIRsensor signals

The operational amplifiers inSTMicroelectronics’ new TSU10x seriesdraw an extremely low current, enablingdesigners to optimise their powerbudget and extend battery lifetime.

The TSU101, TSU102 and TSU104 provideaccurate signal conditioning of high-impedancesensors; the TSU104 is particularly well suitedfor use with Passive Infra-Red (PIR) presence-detection sensors.

A PIR sensor may be used in a battery-powered system to detect the presence of aperson in its field of vision. It is commonlyused in security systems, automatic doors andautomatic light controls.

The TSU104, which integrates four op-ampsinside a single package and offers 8kHz ofgain bandwidth, can amplify and filter the smallsignal generated by a PIR sensor.

Its tiny 3mm x 3mm package helps to keepthe system’s board footprint to a minimum,and thus helps OEMs to reduce bill-of-materialsand manufacturing costs.

Featuring a no-load current of 580nA perchannel, the TSU10x op amps draw lesscurrent than is supplied by the typical self-discharge current of a lithium-ion battery.

TSU10x op amp: 580nA no-load current per channel

ATMEL

STMICROELECTRONICS

APPLICATIONS• Ultra-violet and photo-sensors • Electrochemical and gas sensors • PIR sensors• Battery-current sensing • Medical instrumentation

FEATURES• 5pA maximum input bias current at 25°C• Operating-voltage range: 1.5V to 5.5V• Unity gain stable • Rail-to-rail input and output • 2kV ESD rating according to human body

model• Operating temperature range:

-40°C to 85°C

SECURITYAUTOMOTIVEMEDICALLIGHTINGINDUSTRIALENERGY CONSUMER TELECOMMS

APPLICATIONS• Industrial IoT equipment • Wearable devices• Point-of-sale terminals

FEATURES• Floating point unit • Dual CAN-FD controller• 10/100 Ethernet MAC with IEEE 1588• Two Hi-speed USB ports • One 12-bit image sensor controller with

Raw Bayer support• Free Linux distribution • 40 peripheral drivers encoded in C


STARPRODUCT

For samples or pricing [email protected]:


The SAMA5D2 Xplained Ultra is a fast prototyping andevaluation platform for the SAMA5D2 series of MPUs.The board includes an ATSAMA5D27-CU MPU andeMMC and DDR3 memories, as well as a rich set ofconnectivity options. Orderable Part Number: ATSAMA5D2-XULT

FREEBOARDS

Apply now at my-boardclub.comFast-track board request code: FTM61A

CCMOS’ CCS811: page 4PARTNERWORKING

ST’s STM32L486xx: page 4NXP’s PCAL6524: page 5PARTNERWORKING

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

4

Digital gas sensor offers lowpower consumption

Cambridge CMOS Sensors (CCS) haslaunched the CCS811, the first digitalproduct in its family of ultra-low-powerminiature gas sensors.

The CCS811 integrates a metal-oxide gassensor with a microcontroller sub-system, anADC and an I2C interface in a single package.Providing an easy-to-use digital measurementof ambient gas concentrations, the CCS811may be used for indoor air-quality monitoringwhen embedded in wearables, connected-home devices, HVAC systems andsmartphones.

Its highly integrated design makes systemimplementation easy and helps to reduce bill-of-materials costs. The internal MCU performsthe processor operations required to generatemeasurements of equivalent CO2 levels or totrigger Volatile Organic Compound (VOC)indicators without intervention by the hostsystem’s processor.

The CCS811 can be used to detect ethanol(alcohol) and hazardous gases such as carbonmonoxide and a wide range of VOCs. Itsunique micro-hotplate sensing technologygreatly reduces power consumption whencompared to traditional metal-oxide gassensors, as it provides for very fast cycle andmeasurement times.

The CCS811 is available in a 2.7mm x4.0mm LGA package.

CCS811: detects ethanol and hazardous gases

CAMBRIDGE CMOS SENSORS

APPLICATIONS• Smart home devices• Smart office devices

FEATURES• <1.2mW average power consumption

during active sensor measurement • <6µW power consumption in Idle mode• Rated for >5 year lifetime



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The CCS_EVK04_DEV consists of a CCS811 sensordaughter board with I2C interface and an I2C-to-USBbridge board to enable connection to a computer.Windows®-based software is available for sensormeasurements and for logging results. Orderable Part Number: CCS_EVK04_DEV

FREEBOARDS


Atmel’s SAMA5D2: page 3PARTNERWORKING

32-bit MCUs combine performance andultra-low energy use

STMicroelectronics has reduced thepower required to operate asophisticated 32-bit microcontroller toa new low level with the introduction ofits STM32L4 series of MCUs.

The first two microcontrollers in the series, theSTM32L476 and STM32L486, feature an80MHz ARM® Cortex®-M4 core with DSP andfloating-point unit. This low-power core iscombined in the STM32L4 devices with the START Accelerator™, which provides for zero-waitexecution of instructions from Flash.

This combination of low-power technologiesenables the devices to achieve up to100DMIPS while drawing just 100µA/MHz. Upto 1Mbyte of dual-bank Flash and 128kbytesof SRAM support sophisticated applicationsand read-while-write capability.

The ultra-low power consumption of thesenew MCUs has been verified in independenttesting against the standard EEMBC™

ULPBench® benchmark: in tests comparingthe efficiency of various ultra-low-powermicrocontrollers, the STM32L476 andSTM32L486 scored 123, the best in the industry.

Other low-power technologies implemented byST in the STM32L4 microcontrollers include:• dynamic voltage scaling to balance power

consumption with processing demand • the FlexPowerControl architecture• seven power-management modes with sub-

mode options. These include Stop, Stand-by, and Shut-down modes, in which currentis as low as 30nA

• Batch acquisition mode for efficient dataexchange with communication peripheralswhile in low-power mode

The STM32L476 and STM32L486 also featurethree 12-bit ADCs operating at up to5Msamples/s. Hardware oversampling enablesthe devices to achieve an upscaled 16-bitresolution.

APPLICATIONS• Internet of Things devices • Industrial equipment • Medical equipment • Consumer products

FEATURES• Two 12-bit DACs• Voltage-reference buffer• Two ultra-low-power comparators• Two op amps• 256-bit AES hardware cryptographic

co-processor• Internal RC clock source accurate to ±1% • Digital filter for sigma-delta modulator• 2 ultra-low-power timers



STMICROELECTRONICS

The STM32L4 Discovery Kit combines an STM32L476MCU with an LCD screen, LEDs, audio DAC,microphone, gyroscope and compass, joystick andconnectivity features. It includes an embedded ammeterwhich measures the MCU’s power consumption in low-power modes. Orderable Part Number: STM32L476G-DISCO

FREEBOARDS


NXP’s PCAL6524: page 5ST’s TSU10x: page 3PARTNERWORKING



Level-shifting I/O expander supports ultra-low-voltage operation

The PCAL6524 is a 24-bit general-purpose I/O expander which providesremote I/O expansion suitable for mostmicrocontrollers, via a Fast-mode Plus(Fm+) I2C bus interface. Its ultra-low-voltage interface allows for directconnection to an MCU operating at avoltage as low as 0.8V.

I/O expanders provide a simple solution whenadditional I/Os are needed while keepinginterconnections to a minimum. This is useful,for example, in battery-powered mobileapplications for interfacing an MCU to sensors,push buttons and a keypad.

In addition to providing a flexible set of GPIOs,the PCAL6524’s built-in level-shifting capabilitysimplifies interconnection of a processorrunning at one voltage level to I/O devicesoperating at a different voltage level.

The PCAL6524 operates from two supplyvoltages: one provides the supply voltage forthe interface at the master side (for example, toan MCU), and the other provides the supply forcore circuits.

The PCAL6524 conforms to the Fm+ I2C busspecification at speeds up to 1MHz, andimplements Agile I/O features such as: • programmable output-drive strength• latchable inputs• programmable pull-up/pull-down resistors• maskable interrupt• interrupt status register• programmable open-drain or push-pull

outputsThe device’s outputs can sink 25mA to directlydrive LEDs.

Advanced audio-processing SoC savesspace and power

ON Semiconductor has released itslatest high-resolution audio-processingSystem-on-Chip (SoC), which enablesdesigners to reduce thesize and prolong thebattery run-time ofmobile devices, wearableaccessories and voicerecorders.

The new LC823450 is basedon a highly efficient ARM®

Cortex®-M3 processor coreand ON Semiconductor’s32-bit/192kHz audio-processing engine. Theaudio engine implementsMP3 encoding and decodingand wireless-audio supportin hardware, which bothboosts performance andreduces power usage.

In addition, a largeselection of royalty- andlicence-free DSP codesamples are available, whichhelp to accelerate software

design and keep development costs to aminimum. These samples include advancedfunctions such as noise cancellation, and S-Live (Low-frequency Intelligence VirtualExcitation) for enhanced playback of lowfrequencies.

With 1.6Mbytes of on-chip SRAM, the newLC823450 has ample memory for audio

processing and application tasks withoutneeding a companion memory chip. Designerscan also take advantage of a number ofintegrated audio peripherals, such as an ADC,a phase-locked loop and a Class D amplifier.In addition, industry-standard interfaces suchas SPI, I2C, SDCard and UART enable productdesigners to provide for connectivity to othersystem functions.

The LC823450 is available in two packagestyles: a 5.5mm x 5.3mm chip-scale package,and a TQFP measuring 14mm x 14mm.

NXP SEMICONDUCTORS

APPLICATIONS• Companion device to a microcontroller

FEATURES• 2µA stand-by current at 3.3V• Internal power-on reset• 5.5V-tolerant I/O ports and 3.6V-tolerant

I2C bus pins • Noise filter on inputs • 2kV ESD protection according to the

human body model


APPLICATIONS• Digital voice recorders• Wireless headsets• Other portable audio devices• High-resolution audio players

FEATURES• I2S interface • DSP code for FLAC codec• Hi-Speed USB2.0 device/host interface • Oscillation controller to dynamically

change clock frequency




ON SEMICONDUCTOR

LC823450: encodes/decodes MP3 files in hardware

ST’s TSU10x: page 3ST’s STM32L486xx: page 4PARTNERWORKING



P • I • ES E C T I O N

Board-to-board connectors absorb largemounting misalignments

The FX22 series of floating board-to-board connectors from Hirose canabsorb mounting misalignment whenused in applications in which multipleconnectors are found on the sameboard.

The FX22 connector range consists oflow-profile headers and receptacleswhich provide a co-planar board-to-board connection. The header has aunique floating structure embeddedinside the housing. This allowsmovement in the x and z directions ofup to ±0.6mm, absorbing mountingmisalignments and reducing the riskof mounting failure.

Large mating guides on each sideof the connector also allow for analignment movement of ±1.2mm inthe x and z directions to simplify themating operation and to preventincorrect insertion.

The receptacle features double beam contacts.Each beam requires a different contact force toensure dissimilar vibration characteristics anddifferent resonant frequencies, helping tominimise contact damage and providing forhigh vibration resistance. Furthermore, the firstbeam contact has a self-cleaning function whichremoves dust from the contact path of thesecond beam contact, thus improving reliability.

The popular, high-speed FX18 series board-to-board connectors may be combined with

the floating FX22 connectors on the sameboard. In addition, the FX20 series can becombined with the FX22 to provide a vertical orparallel connection.

Robust, IP67-rated switches canwithstand 5 million button presses

C&K has introduced the KSC range oftactile dome-contact switches, whichare suitable for use in applicationsrequiring a lifetime rating of as many as 5 million cycles.

The switches developedby C&K are the KSC201J/G LFS, the KSC401J/G 50SH LFS, theKSC701 J/G LFS and theKSC1001 J/G LFS.These parts givedesigners a choice ofcolours, dome sizes anddome styles.

All provide positivetactile feedback to theuser, and are IP67-ratedfor protection againstmoisture and otherenvironmental hazards.

The switches are suitable for surface mounting,and offer J-bend or gullwing-type terminations.The termination material determines theoperating temperature rating. Switches withsilver terminations are rated for operation attemperatures between -40°C and 85°C. Withgold terminations, this range is extended tocover -55°C to 125°C.

KSC switches: choice of colours, dome sizes and dome styles

HIROSE

C&K COMPONENTS

APPLICATIONS• Industrial equipment• Broadcast equipment• Smart meters• Medical devices• Base transmitter stations• Measuring instruments • Projectors

FEATURES• Contact sizes: 40, 50, 60, 80 • 0.7A current rating• 0.5mm pitch • 50V rating• 50 mating cycles


APPLICATIONS• Automotive devices• Industrial electronics equipment• Network infrastructure • Computing equipment

FEATURES (KSC2 series)• Maximum power:

1VA for silver; 0.2VA for gold• 32V DC maximum voltage • 20mV minimum voltage • Maximum current:

50mA for silver; 10mA for gold• Minimum current:

1mA for silver; 0.1mA for gold• >250V dielectric strength • <100mΩ contact resistance • >10MΩ insulation resistance• <1ms bounce time




Hirose’s FX22: first beam contact has a self-cleaning function

D E S I G N N O T E

7FOLLOW US NOW – SEARCH FTM BOARD CLUB ON


INTERSIL

A Low Dropout regulator (LDO) is generally thought of as asimple and inexpensive way to regulate and control an outputvoltage which is produced from a higher input-voltage supply.However, cost and simplicity are not the only reasons for theirwidespread use. In fact, today’s systems are getting morecomplex, noise-sensitive and power-hungry. The widespreaduse of switching power supplies at all power levels meansthat designers must spend more time avoiding noise-couplingand interference, while improving system efficiency, so costand simplicity cannot be the only factors affecting powercomponent choices.

For most applications, a datasheet’s specifications of basic parametersare clear and easy to understand. Unfortunately, datasheets do not listthe parameters for every possible circuit condition. Therefore, to makethe best use of an LDO, it is necessary to understand the keyperformance parameters and their impact on any given load. Designerswill need to determine whether the LDO is suitable for a specific load byclosely analysing the prevailing circuit conditions.

An LDO is comprised of three basic functional elements: a referencevoltage, a pass element and an error amplifier. During normal operation,the pass element behaves as a voltage-controlled current source. Thepass element is driven by a compensated control signal from the erroramplifier, which senses the output voltage and compares it with thereference voltage. Each of these functional blocks affects the LDO’sperformance. LDO manufacturers’ datasheets always includespecifications that indicate the performance of these functional elements.

Dropout voltageDropout voltage is defined as the difference between the input andoutput voltages at the point when a further decrease in input voltagecauses output voltage regulation to fail. In the dropout condition, thepass element operates in the linear region and behaves like a resistor.For the modern LDO, the pass element is commonly implemented withPMOS or NMOS FETs, which can typically achieve a dropout voltageranging between 30mV and 500mV. Figure 1 shows the dropout voltageof the ISL80510 LDO, which uses a PMOS FET as the pass element.

Load regulationLoad regulation is defined as the output voltage change for a given loadchange. This is typically from no load to full load:

Load regulation indicates the performance of the pass element and theclosed-loop DC gain of the regulator. The higher the closed-loop DCgain, the better the load regulation.

Fig. 1: Dropout voltage of Intersil’s ISL80510

Line regulationLine regulation is the output voltage change for a given input voltagechange, as shown in the following equation:

Since line regulation is also dependent on the performance of the passelement and closed-loop DC gain, dropout operation is often notincluded when considering line regulation. Hence, the minimum inputvoltage for line regulation must be higher than the dropout voltage.

Power-supply rejection ratio The Power-Supply Rejection Ratio (PSRR) is an indication of the LDO’sability to attenuate fluctuations in the output voltage caused by the inputvoltage. While line regulation is only considered at DC, PSRR must beconsidered over a wide frequency range:

The PSRR consists of the closed-loopgain, T(s), and the inverse of the open-loop transfer function from input to outputvoltage, 1/Gvg, as shown in Figure 2.While the closed-loop transfer functiondominates at lower frequencies, the open-loop transfer function from input to outputvoltage dominates at higher frequencies.

NoiseThis parameter normally refers to the noise on the output voltagegenerated by the LDO itself, which is an inherent characteristic of thebandgap voltage reference. Most low-noise LDOs need an additionalfilter to prevent noise from entering the closed loop.

Transient responseLDOs are commonly used for point-of-load regulation of digital ICs,DSPs, FPGAs and low-power CPUs, where the transient behaviour ofthe LDO is of high importance.

As in all closed-loop systems, the transient response mainly dependson the bandwidth of the closed-loop transfer function. To achieve thebest transient response, the closed-loop bandwidth has to be as high aspossible while ensuring sufficient phase margin to maintain stability.

Although an LDO’s conversionefficiency is lower than that of aSwitch-Mode Power Supply(SMPS), in many applications theLDO is to be preferred. In noise-sensitive applications, it is difficultfor an SMPS to achieve thenecessary output ripple to meet atight noise specification.Consequently, it is not uncommonfor an LDO to be added as anactive filter to the output of an

SMPS. This LDO must have high PSRR at the SMPS’ switchingfrequency.

LDOs are particularly well suited to applications that require an outputvoltage regulated to slightly below the input voltage.

Favourable parameters of ISL80510For mid- to high-current applications, Intersil’s ISL80510/05 providesbalanced performance across all the important LDO performanceparameters: low dropout, transient performance, voltage accuracy and anear flat PSRR response across a wide range of frequencies, as shownin Figure 3.

A guide to the key performance parameters of LDOs

Fig. 2: PSRR plotted against frequency

Fig. 3: Transient response of the ISL80510(2.2VIN, 1.8VOUT)

VISHAy

The question of how to turn on a MOSFET might soundtrivial, since ease of switching is a major advantage of field-effect transistors. Since MOSFETs are voltage-driven, manyusers assume that they will turn on when a voltage, equal toor greater than the threshold, is applied to the gate.

Power MOSFETs: understand

More important, the curve showing data with the MOSFET fully on iscalled the output characteristics curve, as shown in Figure 2. Here, theMOSFET’s forward drop is measured as a function of current for differentvalues of the gate-source voltage. System designers may refer to thiscurve when they wish to ensure that the gate voltage is sufficient.

As Figure 2 shows, for each gate voltage at which an on-resistancevalue is guaranteed, there is a range in which the drain-source voltagedrop maintains strict linearity with current, beginning from zero. For lowervalues of gate voltage, as the current is increased the curve loses itslinearity, goes through a knee, and flattens out.

A closer view of the output characteristics for gate voltages between2.5V and 3.6V is shown in Figure 3. MOSFET users usually think of this

as the linear mode. However, device designers refer to the grey area asthe current saturation region: for the given gate voltage, the current thatcan be produced has reached its saturation limit.

Any increase in applied drain-source voltage will be sustained withonly a slight increase in the current, whereas even a slight change incurrent can lead to a relatively large increase in the drain-source voltage.For higher gate voltages, when the MOSFET has been fully turned on,any operating point will be located in the area shaded in green to theleft, marked as the resistive (or ohmic) region.

D E S I G N N O T E


However, the question of how to turn on a MOSFET or, at a more basiclevel, what is the minimum voltage that should be applied to the gate,needs reappraisal now that more and more converters are beingcontrolled digitally. While digital control offers flexibility and functionality,the DSPs, FPGAs and other programmable devices with which it isimplemented are designed to operate with low supply voltages. It isnecessary to boost the final PWM signal to the level required by theMOSFET gate.

This is where things can go wrong: many digital designers look at thegate threshold voltage and assume that, just like a logic function, theMOSFET will change state as soon as the threshold is crossed. Thisassumption, unfortunately, is wrong.

In fact, the gate-source threshold voltage value is not even intendedfor use by system designers. It is the gate voltage at which the draincurrent crosses the threshold of 250µA. It is also measured underconditions that do not occur in real-world applications. The truth is thatthe threshold voltage is a MOSFET designer’s parameter. It defines thepoint at which the device is at the threshold of turning on. In otherwords, it is an indication of the beginning of the process, and is nowherenear the end of it.

Certainly, the gate voltage should be held below the threshold in theoff state to minimise leakage current. But for the purposes of turning onthe MOSFET, system designers can, and should, ignore the thresholdvalue entirely.So what information should the system designer turn to? A MOSFETdatasheet will have a curve which shows the MOSFET turning on with

increasing gate voltage: the transfer characteristics. This is illustrated forVishay’s SiR826ADP MOSFET in Figure 1.

The transfer characteristics, however, are most useful as a measure ofcurrent variation with respect to temperature and applied gate voltage.

Fig. 1: The SiR826ADP’s transfer characteristics

Fig. 2: The SiR826ADP’s output characteristics

Fig. 3: Detailed view of the SiR826ADP’s output characteristics


ing the turn-on process

When confronted with the output characteristics, designers tend todemand to know the on-resistance at their particular operatingconditions. Typically it will be at a combination of the gate-sourcevoltage and the drain-source current when the curve has strayed fromthe straight and narrow into the grey area.

In fact, the real key to turning on the MOSFET is provided by the gate-charge curve shown in Figure 4. While this curve is routinely provided in

every MOSFET’sdatasheet, itsimplications are notalways understood bydesigners. In addition,recent developments inMOSFET technology,such as trench andshielded gates andcharge-compensatingsuperjunctionstructures, demand afresh appraisal of thisinformation.

To start with, the term‘gate charge’ itself is somewhat misleading. The linearised andsegmented curve does not look like the charging voltage of anycapacitor, no matter how non-linear its value. In reality the gate-chargecurve represents a superposition of two capacitors which are not inparallel, have different values, and carry different voltages.

In the literature, the effective capacitance, Ciss, as seen from the gateterminal is defined as the sum of the gate-source capacitance and thegate-drain capacitance.

While this is a convenient entity to measure and specify in thedatasheet, it is worth noting that gate charge is not a physicalcapacitance. It would be a misconception to imagine that the MOSFETis turned on by simply applying a voltage to ‘the gate capacitance Ciss’.Before turn-on, the gate-source capacitance is uncharged, but the gate-drain capacitance has a negative voltage/charge which needs to beremoved. Both capacitors are non-linear; their values can vary widelywith respect to applied voltage. The switching characteristics, therefore,are dependent more on their stored charges rather than the capacitancevalue at any given voltage.

Since the two component capacitances that make up gatecapacitance are physically different and are charged to different voltages,the turn-on process also has two stages. The exact sequence isdifferent for inductive and resistive loads; in most applications, however,the load is heavily inductive and can be described using the circuit modelshown in Figure 5.

The timing diagram is shown in Figure 6:

T0 – T1: gate-source capacitance is charged from zero to the thresholdvoltage. There is no change in the drain-source voltage or current.

T1 – T2: current begins to rise in the device as the gate voltage risesfrom its threshold value to the plateau voltage. Drain-source current risesfrom 0A to the full load current, but there is no change in drain-sourcevoltage. The charge associated with it is the integral of the gate-sourcevoltage from 0V to the plateau voltage, and is specified in datasheets as‘Qgs’.

T2 – T3: the flat region between T2 and T3 is also known as the Millerplateau. Before turn-on, the gate-drain capacitance is charged to thesupply voltage and holds it until the current has peaked at T2. BetweenT2 and T3, the negative charge is converted to the positive chargecorresponding to the plateau voltage. This is also seen as a fall of thedrain voltage from the input voltage to near zero. The charge associatedwith this is approximately the integral of the gate-drain capacitance fromzero to the input voltage, and is specified in datasheets as ‘Qgd’.

T3 – T4: as the gate voltage rises from the plateau voltage to the gate-source voltage, there is very little change in the drain-source voltage orcurrent. The effective on-resistance, however, reduces marginally withthe rising gate voltage. At some voltage above the plateau voltage,MOSFET manufacturers feel confident enough to guarantee an upperlimit to the effective on-resistance.

In the real world, then, turning on a MOSFET is not an event but aprocess. It is not a question of applying a voltage as an input at the gatewhich will toggle the output from high to low on-resistance. It is the twocharges, Qgs and Qgd, injected into the device through the gate pin,which do the job.

The gate voltage will rise above the threshold and plateau values inthe process, but that is a by-product of the turn-on process.

In addition, the speed with which a modern power MOSFET turns onor off is not a simple function of Qgs or Qgd. A detailed study of both thegate-charge curve and capacitance characteristics is necessary tocompare switching speeds, especially for superjunction MOSFETs.

D E S I G N N O T E

9FOLLOW US NOW – SEARCH FTM BOARD CLUB ON

Fig. 4: SiR826ADP’s gate-charge characteristics

Fig. 5: Simplified inductive turn-on circuit

Fig. 6: Gate-charge components and timings

C I R C U I T C E N T R E


Interest in implementing Brushless DC (BLDC) motors isgrowing fast as OEMs respond to the worldwide effort tosave energy and resources by adopting efficient,electronically commutated motor types.

BLDC motors are one of the most popular choices of newmotor technology. Typically up to 10% more power-efficientthan common AC motors, BLDC motors are also smaller andlighter, and offer long lifetimes because they have no brushesto wear out. Sophisticated commutation schemes alsoenable them to rotate at high speed: designers commonlyachieve speeds of 20,000rpm using BLDC technology.

While BLDC motors can be implemented with a widerange of power ratings, they all share common elements: • a control block using either a dedicated ASSP, a

microcontroller or a DSP• a power block using MOSFET or IGBT switching devices• communication, which can be achieved in various ways,

including dedicated fieldbuses and Ethernet

In addition, sensorless control is possible, but manydesigners will choose to use a position sensor, as well asisolation barriers where appropriate.

Future Electronics’ suppliers have partnered with us tooffer their best-in-class parts to fit these functional blocks,featured in this new Circuit Centre section. We hope youenjoy this new section of FTM, and that over time itbecomes a useful library of good ideas for you to implementin your designs.

Colin WeavingTechnology Director, Future Electronics (EMEA)

Recommended Partsn POWER SUPPLYFairchild: FAN7930Fairchild: FAN6605STMicroelectronics: L6699STMicroelectronics: STSR2P

n OPTOCOUPLEREverlight: EL071 Everlight: ELS511/611Fairchild: FOD8314Fairchild: HCPL2731M

n GATE DRIVERAtmel: ATA6831CFairchild: FOD3150Intersil: HIP2103/4 Intersil: ISL8003X Vishay: VOW3120

n MCUAtmel: ATmega168PBAtmel: ATSAM E70Microchip: DSPIC30F6010NXP: LPC1518JBD100STMicroelectronics: STM32F100C6T6B

n TEMP SENSORAtmel: AT30TS75ANXP Semiconductors: PCT2075Microchip: MCP9808ON Semiconductor: NCT75

n HALL/MAGNETIC SENSORCrocus: CTSR500Diodes: AH49Diodes: AH182P

n PHYMicrochip: KSZ8091

n IPMFairchild: FSB50260SFLittelfuse: MG06100S-BN4MMON Semiconductor: STK5C4U332J-ESTMicroelectronics: STGIB15CH60TS-L(E)STMicroelectronics: STGIF10CH60TS-L(E)Vishay: CPV362M4FPbF

n POWER FETsFairchild: FCP220N80STMicroelectronics: STB15N80KSSTMicroelectronics: STW21N150K5STMicroelectronics: STW12N150K5

n DISCRETE IGBTsFairchild: FSBB20CH60Microsemi: APT25GR120BSCD10

DIODESON Semiconductor: MBR40250STMicroelectronics: STTH12R06

CAN TransceiverMicrochip: MCP2551NXP Semiconductors: TJA1057GTKON Semiconductor: NCV7341

Development ToolsFuture/NXP Semiconductors: FSB1500STMicroelectronics: P-NUCLEO-IHM001

World’s first 1,500V MOSFETs for safer, greener powerA new family of power MOSFETs from STMicroelectronics, the MDmesh™ K5 devices, are the first in the world to combinethe benefits of superjunction technology with a very high drain-to-source breakdown voltage of 1,500V.

ST’s improved superjunctiontechnology offers new highlevels of performance, includingthe lowest on-resistance as afactor of area, the lowest gatecharge, and the industry's bestFigure of Merit (FoM).

STMICROELECTRONICSMOSFETThe first two members of the MDmesh K5 family are:• the STW12N150K5, with a maximum drain-to-source current of 7A

and gate charge as low as 47nC• the 14A STW21N150K5, offering on-resistance as low as 0.9ΩThe devices are ideal for electronically commutated motors and allpopular power-supply topologies, including standard, quasi-resonantand active-clamp flyback converters, and LLC half-bridge converters.• 4V gate-source threshold voltage• Withstands up to 50V/ns transients• Junction-temperature range:

-55°C to 150°C

BLDC Motor Control

For more information e-mail [email protected]

160113:



Hall-effect sensors provide stableand accurate position dataThe AH49 from Diodes Incorporated is a series of small,versatile linear Hall-effect sensors which are available inSOT23, SC59 and TO92 packages, and with various levels ofmagnetic-field sensitivity.

The output voltage midpoint is at half of the supply voltage and varies inproportion to the polarity and strength of the magnetic field about this

midpoint. This makes theAH49 series ideal for use asposition sensors inelectronically commutatedmotors such as brushless DCmotors.• Low-noise output• Integrated precision

resistors for hightemperature stability andaccuracy

• Low-power operation:3.5mA current at 5V supply


160116:

DIODES INCORPORATEDHALLSENSOR

Half-bridge driver enablessmooth control of DC motorsAtmel’s ATA6831C is a fully-protected triple half-bridgedriver which enables a microcontroller to control a motor inautomotive and industrial applications.


160115:

ATMELGATEDRIVER

PC-controlled application boardOrderable Part Number: ATA6831-DK

FREEBOARDS


Each of the three high-side and three low-sidedrivers, internallyconnected to form threehalf-bridges, can drivecurrents up to 1.0A. Ableto support PWMfrequencies up to 25kHz,the ATA6831C cansmoothly control two DCmotors or a singlebrushless DC motor.• Supply voltage up to 40V• 0.8Ω on-resistance• 1.0A maximum output

current

Highly integrated Ethernet PHy includeson-chip low-noise 1.2V regulatorMicrochip’s KSZ8091 is a 10/100 Ethernet physical-layertransceiver (PHY), suitable for transmitting and receivingdata over standard CAT-5 unshielded twisted pair cable.

A highly-integrated PHy, the KSZ8091 uses on-chip termination resistorsfor the differential pairs, integrates a low-noise regulator to supply the1.2V core, and offers a flexible, digital I/O interface. The KSZ8091 alsoprovides diagnostic features to facilitate system bring-up and debuggingin production testing and in product deployment.

• Energy Efficient Ethernet (EEE) support • Wake-On-LAN (WOL) support with

either magic packet, link statuschange, or robust custom-packetdetection

• Power-down and power-saving modes


160117:

MICROCHIPPHY

Orderable Part Number: KSZ8091RNA-EVAL

FREEBOARDS


Temperature sensor achievesaccuracy of ±1°CThe PCT2075 from NXP Semiconductors is a temperature-to-digital converter which is accurate to ±1°C over a rangeof -25°C to 100°C.

The device can be configured to work as a thermal watchdog, since itincludes an open-drain output which becomes active when thetemperature exceeds programmed limits.

The PCT2075 can be configured for different operating modes. It canbe set in Normal mode to periodically monitor the ambient temperature,or in Shut-down mode to minimise power consumption.

• Pin-for-pin replacementfor LM75 series

• Operating temperaturerange: -55°C to 125°C

• <1µA supply current inShut-down mode


160114:

NXP SEMICONDUCTORSTEMPSENSOR


13 VISIT THE ONLINE FTM MAGAZINE AT: WWW.My-FTM.COM

300MHz MCU includes multipleconnectivity and analogue featuresOperating at 300MHz, the high-performance SAM E70 ARM®

Cortex®-M7 processor-based MCU scores a 1500 CoreMark.

With up to 2Mbytes of Flash and 384kbytes of SRAM, the device offerstightly linked peripherals which manage events without the intervention ofthe CPU. The SAM E70 series is pin-compatible with the SAM4E series.

• One Ethernet MAC (GMAC) 10/100Mbps in MII mode and RMII withdedicated DMA

• Two master Controller Area Networks(MCAN) with Flexible Data Rate (CAN-FD)

• Two 4-channel 16-bit PWMs withcomple-mentary outputs

• Four 3-channel 16-bit timers/counters• Hi-speed USB host and device with on-

chip high-speed PHy• Dual 12-bit ADCs and dual 12-bit DACs


160118:

ATMELMCU

Bridge drivers deliver longbattery life and high reliabilityIntersil’s HIP2103 and HIP2104 half-bridge driverssignificantly extend the battery run-time and overall productlife of multi-cell lithium-ion battery-powered devicesoperating from a supply voltage between 5V and 50V.

Featuring the industry’s lowest Sleep-mode current and a bridge phasenode pin which eliminates any kickback voltage, these half-bridge driverdevices are ideal for power tools, home automation products and

portable medicalequipment in whichbattery life, longevity andhigh reliability are required.• 60V maximum bootstrapsupply voltage• 5µA quiescent current• Integrated bootstrapFET (emulates the bootdiode)


160119:

INTERSILGATEDRIVER

See Board of the Month on page 25Orderable Part Number: ATSAME70-XPLD

FREEBOARDS


Orderable Part Number: HIP2103-4DEMO1Z

FREEBOARDS





Space-saving optocouplersprovide 5,000V isolationEverlight has announced the introduction of two newsingle-channel optocouplers intended for use in industrialapplications.

The 1Mbit/s ELS511 and 10Mbits/s ELS611 are housed in a small 6-pin SOP package measuring 6.8mm x 4.6mm. The devices help usersto save PCB space, and are ideal when implementing a size-reductiondesign.

The ELS511 optocouplers consist of an infrared emitting diode,optically coupled to a high speed photo-detector transistor. A separateconnection for the photodiode biasand output-transistor collectorincreases the speed by several ordersof magnitude compared toconventional phototransistor couplersby reducing the base-collectorcapacitance of the input transistor.

• 5,000Vrms isolation voltage betweeninput and output

• Guaranteed performance from 0°C to 70°C

• Operating temperature range: -55°C to 100°C For more information

e-mail [email protected]

160124:

EVERLIGHTOPTO

32-bit MCU comes with motor-control firmware and an on-chip QEINXP Semiconductors’ LPC1518 microcontroller provides thefeatures and functions needed to quickly and easilyimplement a high-precision motor-control system.

Based on the ARM® Cortex®-M3 processor, the LPC1518 has two 12-bit,12-channel, 2Msamples/s ADCs and an on-chip quadrature encoderinterface to enable highly accurate control of both sensored andsensorless motors. Four flexible state-configurable timer/PWM blocksprovide up to 28 PWM channels.

NXP also offers efficient motor-control firmware, easy-to-use GUI-basedtuning tools, and two new motor-control solution kits for the LPC1500 series of MCUs.

• Up to 128kbytes of Flash • 20kbytes of SRAM• CAN interface• Real-time clock


160121:

NXP SEMICONDUCTORSMCU

New logic gate optocoupler offershigh data rate needed in industrialapplicationsEverlight Electronics’ EL071L is a single-channel logic gateoptocoupler offering a data transmission rate of 15Mbits/s.

The EL071L consists of an infrared emitting diode optically coupled to aCMOS detector IC, and is ideal for isolating circuit elements in motordrives and other industrial applications.

The optocoupler is housed in an 8-pin 4.88mm x 5.85mm x 3.18mmSOP package.

• 3.3V and 5V CMOScompatibility

• 10kV/µs minimumcommon-mode transientimmunity

• 3,750Vrms isolationvoltage between inputand output

• Guaranteedperformance from -40°C to 110°C


160123:

EVERLIGHTOPTO

Orderable Part Number: FSB1500

FREEBOARDS


Complete development kit for aBLDC motor-control circuitSTMicroelectronics has released an STM32 motor-control kitbased on an X-NUCLEO-IHM07M1 three-phase driver boardand a NUCLEO-F302R8 32-bit microcontroller board.

The P-NUCLEO-IHM001 platform provides a complete control solutionfor a low-voltage, three-phase brushless DC motor. The circuit uses an

L6230 driver, a member of the STSPIN family,and an STM32F302R8 microcontroller. The X-NUCLEO-IHM07M1 board is ready tosupport various control schemes, includingclosed-loop control, field-orientedcommutation or six-step control, in eithersensorless or sensor mode. • Operating-voltage range: 8V-48V DC• 2.8A peak output current • Three-phase motor with maximum speed

of 19krpm


160122:

STMICROELECTRONICSIGBT

Orderable Part Number: P-NUCLEO-IHM001

FREEBOARDS



15 VISIT THE ONLINE FTM MAGAZINE AT: WWW.My-FTM.COM

Miniature DC-DC buck convertersprovide 3A continuous outputThe new ISL8003x devices from Intersil are DC-DC buckregulators, producing up to 3A of continuous output currentfrom a 2.7V to 5.5V supply. They offer up to 95% peak efficiency.

The 2mm x 2mm ISL80030, ISL80030A,ISL80031 and ISL80031A, which are pin-compatible with each other, all includehigh-side PMOS and low-side NMOSMOSFETs which have very low on-resistance. As well as reducing the needfor external components, this also helpsto limit power losses. • Typically run without cooling fans or

heat-sinks, resulting in improvedsystem reliability

• 35µA quiescent current• Internal soft-start and soft-stop


160125:

INTERSILGATEDRIVER

3A IPM implements completeinverter stage in a single packageThe STK5C4U332J-E is an Intelligent Power Module (IPM)from ON Semiconductor intended for use as an inverter inmotor-drive systems.

Highly integrated and housed in a single DIP module, it implements acomplete inverter stage from a high-voltage DC input to a three-phaseIGBT output with a maximum continuous output current of ±3A. It offersunder-voltage protection, and internal boost diodes are provided forhigh-side gate boost driving.

All the control-input and status-output signals from theSTK5C4U332J-E are at a low voltage compatible with microcontrollers.• Externally accessible embedded thermistor

for substrate temperature measurement• Built-in cross-conduction prevention• 150°C maximum junction temperature• 2,000Vrms isolation voltage


160126:

ON SEMICONDUCTORIPM


160127:

Orderable Part Number: ISL8003xDEMO1Z

FREEBOARDS


Orderable Part Number: STK5C4U332JGEVB

FREEBOARDS


A P P L I C A T I O N S P O T L I G H T

16

Light-load algorithm improves efficiency of DC-DCbuck converters

AP65x01: valuable cost and board-space savings

Two new synchronous DC-DC buckconverters introduced by DiodesIncorporated offer highly efficientoperation at both full and light loads.

The 1.5A AP65101 and 2AAP65201 achieve efficiency ofup to 97% at their maximumcontinuous current. Theybenefit from a low quiescentsupply current and integratedhigh- and low-side switcheswith low on-resistance, whichhelps to reduce conductionlosses.

At the same time, the newAP65x01 devices offerexcellent efficiency at lowloads because of anautomatic light-load algorithm,which is triggered when theinductor’s peak current fallsbelow a pre-set threshold.

The AP65101 and AP65201 buck convertersare intended for low-voltage regulation,especially in distributed power architectures.They operate from an input-voltage range of4.5 to 16V, producing an adjustable outputvoltage in a range from 0.8V up to 80% of theinput voltage.

The converters’ high level of integration andminimal need for external componentscombined with the small footprint of the

DIODES INCORPORATED

APPLICATIONS• Point-of-load power supplies• Consumer electronics devices• Set-top boxes• Coffee machines• Access points and gateways• Modems

FEATURES• 500kHz switching frequency• Over-current limit• Over-voltage protection • Under-voltage lock-out• Thermal shut-down protection


Wall-plug AC-DC power supplies comply withnew tighter efficiency regulations

CUI Inc., has announced a new line ofwall-plug AC-DC power supplies for theUS, Japanese and European markets.

The SWI6, SWI12, SWI18 and SWI24, whichhave either North American or European inputblades, meet the stringent average-efficiencyand no-load power requirements mandated bythe US Department of Energy in its new levelVI standard. The aim of this standard is to

markedly lower the amount of powerconsumed when the end application is not inuse or is no longer connected to the system.Any manufacturer seeking to market an end-product with an external adapter in the USmust comply with these new provisions by 10February 2016.

The 6W, 12W, 18W and 24W SWI wall-plugadapters all feature a wide universal input-voltage range of 90-264V AC and are availablein single output voltages of 5V, 5.9V, 9V, 12V,15V or 24V. All models meet the Level VIstandard’s no-load power-consumptionrequirement of <0.1W.

Models with input blades for North Americanand Japanese applications offer UL/cUL andPSE safety approvals, while models withEuropean input blades come with the CE mark.All models also satisfy the requirements of theFCC Part 15 Class B standard for EMI/EMC.

CUI’s SWI series: supplied with North American or European input blades

CUI INC

APPLICATIONS• Consumer devices• Industrial equipment • Portable products

FEATURES• 300,000 hours’ MTBF• ±5% typical regulation• Over-voltage protection• Over-current protection• Short-circuit protection• 0.25mA maximum leakage current





TSOT26 package provide valuable cost andboard-space savings. Current-mode operationenables fast transient response and easy loopstabilisation.

The device’s Enable pin has a high voltagetolerance of up to 6V.

E N E R G y , P O W E R & P O W E R M A N A G E M E N T


New chip clamps down on vampire power inappliances, lighting and industrial equipment

ST’s VIPer0P: supports flyback, buck and buck-boost topologies

The phenomenon of ‘vampire power’ –the energy used by equipment which isstanding idle – could be about to endthanks to the latest power-supply chipfrom STMicroelectronics.

The new VIPer0P AC-DC power converter fromST can drive down stand-by power consumptionto 5mW while fed by a 230V AC supply. This isrounded to zero according to the IEC 62301standard for household and office appliances.

The converter is also the first in the world toprovide a smart way of managing the wake-upfunction. In the VIPer0P, ST has introduced apatented smart-management capability notoffered by any other converter in the market:because it is able to provide stand-by powerfor the host microcontroller while in Idle mode,the system may be woken via the mainappliance’s user interface, such as atouchscreen or remote control. This means thatthere is no need for a dedicated high-voltagemechanical switch to take the appliance out ofStand-by mode.

If a switch is used to control stand-by operation,Idle power can be reduced even more, to4mW. Switching can be performed at SafetyExtra-Low Voltage (SELV) levels, eliminating theneed for bulky high-voltage components.

VIPer0P may be configured as a flyback,buck, or buck-boost switched-mode powersupply. It integrates an avalanche-ruggedpower MOSFET with a breakdown voltage of800V, giving designers a high safety margin forsuperior reliability.

Other features include integrated high-voltage start-up circuitry, and a sense-FET forenergy-efficient current sensing. In addition,VIPer0P’s self-supply design simplifiestransformer selection by eliminating the needfor an auxiliary winding.

Efficient 600V MOSFETs reduceeffects of gate loop inductance

Vishay Intertechnology has extended its 600V E series of power MOSFETs withnew devices housed in its compact PowerPAK® 8mm x 8mm package, providing aspace-saving alternative to conventional TO-220 and TO-263 solutions.

The new Vishay Siliconix SiHH2xxN60E parts feature a large drain terminal for low thermalresistance. In addition, the construction of the PowerPAK® 8x8 package allows one of the sourcepins to be arranged as a dedicated Kelvin source connection which separates the gate-drivereturn path from the main current-carrying source terminals.

This prevents the voltage drop in the high-current path attributable to gate loop inductance fromreducing the gate-drive voltage applied to the MOSFET. This in turn leads to faster switching andbetter noise immunity in high-performance power-supply designs.

Based on Vishay's latest energy-efficient E series superjunction technology, the SiHHxxN60Edevices offer low on-resistance and gate charge. These values result in extremely low conductionand switching losses, helping reduce energy consumption in power factor correction circuits,flyback converters, and two-switch forward converters. They are designed to withstand highenergy pulses in the avalanche and commutation modes.

STMICROELECTRONICS

VISHAy

APPLICATIONS• Home appliances• Home automation• Industrial equipment• Lighting • Consumer devices

FEATURES• Current-mode PWM controller • Over-current protection • Jittered switching frequency reduces EMI

filter cost • Embedded error amplifier with 1.2V

reference • Pulse-skip protection to prevent flux

runaway • Embedded thermal shut-down


APPLICATIONS• Server and telecoms power supplies• HID and fluorescent lighting ballasts• Power adaptors• Motor drives• Solar PV inverters• Induction heating• Welding equipment

FEATURES (SiHH26N60E)• 353mJ maximum pulse avalanche energy• 0.48°C/W junction-to-case thermal

resistance • Junction-temperature range:

-55°C to 150°C




Part Number Drain-sourceVoltage (V)

Gate-sourceVoltage (V)

Drain Current(A) at 25°C

Maximum On-resistance (Ω)

at 10V

Typical GateCharge (nC) at

10V

Typical GateCapacitance

(pF)

SiHH26N60E 600 ±30 25 0.135 77 2815SiHH21N60E 600 ±30 20 0.176 55 2015SiHH14N60E 600 ±30 16 0.228 41 1416SiHH11N60E 600 ±30 11 0.339 31 1076

This evaluation kit demonstrates a 7W dual-output (7V/-5V) flyback converter with a non-isolated topology,based on the VIPer0P off-line converter IC. Orderable Part Number: STEVAL-ISA174V1

FREEBOARDS



18

New SiC power module offers hugely improvedswitching performance

SiC power modules: lower electrical stress for long lifetime

ROHM Semiconductor has introduced anew 180A Silicon Carbide (SiC) powermodule which benefits from thedramatic reduction in on-resistanceprovided by the double-trench structureof its latest SiC MOSFETs.

The BSM180D12P3C007 module is a1,200V/180A full SiC power module whichincludes third-generation SiC trench MOSFETs.In the new MOSFETs, on-resistance is cut inhalf by comparison with the previousgeneration of SiC MOSFETs, which have aplanar structure. Input capacitance in the newdevices is some 35% lower.

As a result, switching losses in the newBSM180D12P3C007 module are reduced by42% compared to the ROHMBSM180D12P2C101 module, which containsplanar MOSFETs.

The new double-trench structure alsoenhances the long-term reliability of the newmodule, since it diffuses the electric field

concentrated at the base of the gate trench,lowering the electrical stress on the devicecompared to a MOSFET with a conventionalsingle-trench structure.

ROHM has also expanded its line-up of fullSiC power modules with the new 1,200V/300ABSM300D12P2E, adding to the 120A/180Adevices already available. The new module issuitable for large power supplies in industrialequipment, providing much reduced switchinglosses when compared to conventional siliconIGBT power modules.

ROHM SEMICONDUCTOR

APPLICATIONS• Motor drives• Inverters• Power converters• Induction heating equipment

FEATURES (BSM180D12P3C007)• 180A maximum drain current at a 60°C

case temperature• Junction-temperature range:

-40°C to 175°C• 2,500V AC isolation voltage (1 minute)• 10mΩ typical on-resistance at an 18V

gate-source voltage, drain current of 180Aand a junction temperature of 25°C


Highly efficient DC-DC converter stepsdown 5V rails to supply points-of-load

Intersil has released a highly integratedsynchronous buck regulator whichsteps down 5V rails to Point-of-Load(PoL) inputs as low as 0.6V, suitable forFPGAs, DSPs and microprocessors.

The feature-rich ISL8018 provides up to 8A ofcontinuous output current from a 2.7V to 5.5Vinput supply, whileoffering up to 97%efficiency and higherintegration thancompetitive devices.

The 3mm x 4mmregulator provides aninnovative SyNCIN andSyNCOUT feature whichconnects andsynchronises multipleregulators at the sameswitching frequency in amaster/slaveconfiguration, using aphase-shifting time delay.

ISL8018: enables synchronisation of multiple regulators at the same frequency

INTERSIL

APPLICATIONS• Point-of-load modules • Power supplies for microcontrollers,

processors, FPGAs and DSPs • DC-DC converter modules • Portable instruments • Test and measurement systems • Li-ion battery-powered devices

FEATURES• Complete converter occupies less than

97mm2 footprint• Adjustable current limit• Start-up with pre-bias output and internal

soft-start • Peak-current limiting• Hiccup-mode short-circuit protection





The ISL8018EVAL3Z evaluation board is intended forpoint-of-load applications sourcing from 2.7V to 5.5V. Orderable Part Number: ISL8018EVAL3Z

FREEBOARDS


This prevents On-time overlapping andreduces average current, ripple and input-capacitance requirements, which serves toreduce electro-magnetic emissions and toimprove efficiency.

The ISL8018 also provides for voltageoutput margining to be set at ±10% tocompensate for output-voltage drops inreverse-current conditions. The switchingfrequency is programmable in a range from500kHz to 4MHz, enabling the use of smallpassive components for faster transientresponse and board-space saving.



500mA DC-DC boost converter providesaccurate regulation

PCA9410: fixed 5.0V output voltage for use in NFC terminals

NXP Semiconductor’s new PCA9410and PCA9410A are highly efficient 3MHzstep-up (boost) DC-DC converters. Theyconvert input voltages ranging between2.5V and 5.25V to a fixed output voltage of 5.0V. The output current limit is500mA.

These 1.2mm x 1.2mmdevices are optimised forbattery-powered applications:high conversion efficiency ofup to 94% helps to providefor extended battery life in anyportable product design.

In addition, the devices’switching frequency of 3MHzenables the use of a smallinductor with a value of 1µHor less.

The PCA9410 devices offertightly controlled regulation,

providing output voltage accuracy of ±2% atnominal and static conditions. Even over the fullcurrent, voltage and temperature range, theoutput is accurate to within ±3%.

The PCA9410 totally disconnects the inputfrom the output when disabled. ThePCA9410A connects the input to the outputwhen disabled.

6MHz, 500mA step-down converteroffers valuable system space saving

STMicroelectronics’ ST1S15 is anefficient step-down converter whichprovides an output current of up to500mA from an input voltage rangingbetween 2.3V and 5.5V.

The converter’s main benefits are its highefficiency, typically 85%, and the smallfootprint of the complete power-conversioncircuit. Thanks to its high 6MHz switchingfrequency, the ST1S15 can operate with smallsupporting components: an inductor with anominal value of 470nH, and an outputcapacitor of just 4.7µF. At the same time, theST1S15 produces a very fast and accurate

response to loadand line transients.

The converter canoperate in PulseFrequencyModulation mode,for the highestefficiency underlight-load conditions,or PWM mode fortight regulation andthe best dynamicperformance.

NXP SEMICONDUCTOR

STMICROELECTRONICS

APPLICATIONS• NFC terminals

FEATURES• Current-mode controller • Soft-start function • Reverse-current protection• Over-current protection• Over-temperature protection


APPLICATIONS• Power supplies for DSPs and multimedia

processor cores• Mobile phones• PDAs

FEATURES• 45µA quiescent current • -1.5% typical regulation• 10mV output-voltage ripple in PWM mode • Short-circuit protection • Thermal protection




ST1S15: very small supporting components for space-saving designs



Three new solid-state relays offer current-limitprotection and high isolation

Vishay Intertechnology has introducedthe first three devices in its new VORfamily of hybrid solid-state relays, whichoffer noiseless switching and providehigher reliability and a longer lifetime thantraditional electro-mechanical relays.

The new 1 Form A VOR1142 relays are notablefor their high input-to-output isolation, current-limit protection and low power consumption.They are normally-open single-pole, single-throwswitches. Allowing for simple customisation,the devices feature a modular constructionconsisting of a gallium aluminium arsenideinfra-red actuation control, and MOSFETs forthe switch output.

The single-channel relays are offered in threepackage options:• DIP-6: VOR1142A6• SMD-6: VOR1142B6• SOP-4: VOR1142M4Devices in the SMD-6 andDIP-6 packages have highisolation voltage rating of5,300V/1 minute, whiledevices in the smaller SOP-4 package are ratedfor 3,750V/1 minute.

Electronically isolated,the VOR1142 relays offerclean, bounce-freeswitching over an ambienttemperature range of -40°Cto 100°C.

The devices are VDE and UL certified to meetthe reinforced insulation requirements of mostapplications.

VISHAy

APPLICATIONS• Telecoms power supplies• Metering equipment• Security equipment• Instrumentation• Industrial controls• Battery-management systems• Automatic measurement equipment

FEATURES• 22Ω on-resistance• 140mA load current • 400V load voltage • 0.25mA turn-on current• High surge capability


Automotive buck converter provides adjustableoutput voltage

The NCV894530 from ON Semiconductoris a DC-DC buck converter IC intendedfor use in automotive driver-information systems that operatefrom a downstream voltage rail.It implements a synchronous-rectification conversion schemefor high efficiency.

The output voltage is externallyadjustable in a range from 0.9V to3.3V, and can source up to 1.2A.The converter runs at a switchingfrequency of 2.1MHz, avoidinginterference with the sensitive AMradio band, and enabling the use ofa small inductor.

The NCV894530 provides variousfeatures expected in automotivepower systems, such as integratedsoft-start, hiccup-mode current limit,and thermal shut-down protection.

The device can also be synchronised to anexternal 2.1MHz clock signal.

The NCV894530 is available in the same3mm x 3mm 10-pin DFN package as the dualNCV896530, with a compatible pin-out.

NCV894530 buck converter: avoids interference with AM radio band

ON SEMICONDUCTOR

APPLICATIONS• Automotive audio systems• Automotive infotainment systems• Automotive instrumentation

FEATURES• Input voltage range: 2.7V to 5.5V• 1mA quiescent current (no switching)• Short-circuit protection• Internal MOSFETs• Automatically synchronises with an

external clock• AEC-Q100 qualified




VOR family: high input-to-output isolation



Synchronous rectification controllerideal for LLC resonant converters

SRK2001: two high-current gate-drive outputs

The SRK2001 from STMicroelectronics isa power controller which implements acontrol scheme specifically intended forsecondary-side synchronousrectification in LLC resonant converters.

It provides two high-current gate-drive outputs,each capable of driving one or more N-channelpower MOSFETs. Each gate driver is controlledseparately, and an interlock logic circuitprevents the two synchronous rectifier MOSFETsfrom conducting simultaneously. When used toimplement synchronous rectification in LLCresonant converters, the SRK2001 requiresvery few external components.

The control scheme in this IC provides foreach synchronous rectifier to be switched onas the corresponding half-winding startsconducting, and switched off as its current fallsto zero. The innovative turn-on logic withadaptive masking time, and the adaptive turn-off logic, have the effect of prolonging the timeduring which the MOSFETs are conducting:this eliminates the need for a circuit tocompensate for parasitic inductance.

A low-power mode reduces the currentthrough the converter in light-load and no-loadconditions to a typical 50µA.

New external power supplies eliminate power risks inhome healthcare equipment

SL Power Electronics has introducedits newest family of medical-gradeexternal power supplies, the 60W ME60series for home healthcare equipment.

The new ME60 models meet the requirementsof the IEC 60601-1-2 Fourth edition EMCstandard. They are also approved to AAMIES/CSA C22.2/EN/IEC 60601-1, third editionwith two Means Of Patient Protection(MOPP).

As well as achieving full medicalcertification, the ME60 external powersupplies also address the need for highefficiency, complying with the new USDepartment of Energy’s level VIefficiency standard.

These new models are specificallydesigned for next-generation homehealthcare devices such as surgical andpatient-monitoring equipment, andtherapeutic electro-medical devices,which require a high level of EMC, EMIand AC-input performance.

The feature-rich power supplies use high-quality electrolytic capacitors, which providefor a product life of more than seven years. Inaddition, the ME60 series power supplies arecharacterised by low common-mode noise, andhigh levels of ESD (to IEC 61000-4-2, level 4standard: 8kV/15kV) and surge protection (toIEC 61000-4-5, level 4 standard).

The ME series offers a mean time betweenfailure of longer than 250,000 hours. Inaddition, with many input connection types(IEC 60320 C14, C8 or C18 grounded orungrounded cord set) these models can beused anywhere in the world.

Housed in an impact-resistant IP22-ratedpolycarbonate enclosure, the desktop modelsoffer regulated output power with low ripple,no-load power consumption of less than0.21W, and short-circuit and thermalprotection.

The power supplies comply with theEN55011/CISPR11, FCC Part 15.109 Class Bstandard for conducted and radiated emissionswith a 6dB and 3dB margin respectively.

SL Power ME60: multiple input connection options

STMICROELECTRONICS

SL POWER

APPLICATIONS• AC-DC adapters• High-end flat-panel TVs• Servers• Industrial equipment

FEATURES• Operating-voltage range: 4.5V to 32V• High voltage drain-to-source Kelvin

sensing for each MOSFET• Up to 500kHz switching frequency• 35ns total delay at turn-off• Protection against current reversal


APPLICATIONS• Medical equipment

FEATURES• Input-voltage range: 90V to 264V AC• Operating-temperature range:

0°C to 50°C • Three-year warranty




The STEVAL-ISA170V1 is a 150W converter tailored to atypical specification for an all-in-one computer powersupply or a high-power adapter. This highly efficientpower supply complies with the Energy Star eligibilitycriteria for adapters and computers. Orderable Part Number: STEVAL-ISA170V1

FREEBOARDS




Automotive designers benefit from higher powerdensity with new dual MOSFETs

NXP Semiconductors has extended itsportfolio of automotive powerMOSFETs in the LFPAK56D package,which has a Power-SO8 footprint.

The new BUKxK line of devices increasespower density by fitting two MOSFETs into asingle, robust package without impairingperformance. In fact, the new dual MOSFETsare fully AEC-Q101-qualified for operation attemperatures up to 175°C.

Designers using the LFPAK56D productscan reduce the footprint-per-MOSFET-channelby 77% compared to DPAK devices, and by56% compared to single LFPAK56 devices.The new dual MOSFET packages are availablewith maximum voltage ratings of 30V, 40V, 60Vand 100V.

The LFPAK56D package’s copper clipdesign eliminates the need for wire bonds.

NXP dual-MOSFET package: operates at up to 175°C

NXP SEMICONDUCTORAPPLICATIONS

• Engine and transmission controllers• Braking solenoid and motor drives• Space-constrained automotive switching

applications

FEATURES• High maximum drain-current ratings• Low package resistance and inductance• Low thermal resistance• Footprint compatible with other Power-

S08 packages• Excellent tolerance of high transient

currents • 100% avalanche tested






Efficient external AC-DC power supply complies withnew level VI standard

SL Power Electronics’ new TE60 seriesis a 60W external power supply whichcomplies with the US Department ofEnergy’s new level VI efficiency standard.

The TE60’s high-performance design makes itan ideal solution for use with handheld test andmeasurement equipment andindustrial devices, in which lownoise and rugged performanceare required. It is available inmodels with an output voltage of5V, 12V, 15V, 18V, 24V or 48V.

The TE60 series also offersstrong EMC performance,meeting the requirements of theindustrial-grade EN61000-4-Xstandard, which protects end-useequipment from harsh electricalenvironments. Moreover, the TE60series uses high-qualityelectrolytic capacitors, providingfor a product life of longer thanseven years.

and radiated emissions with a 6dB and 3dBmargin respectively.

The TE60 features convenient IEC 60320C14 grounded or C8 ungrounded input-connector options which can accept input linecords with any appropriate plug configuration.

Easy-to-configure controllerssimplify digital power conversion

The STNRG digital-controller familyfrom STMicroelectronics provides aneasy way for designers to implementan efficient digital power-conversionsystem with enhanced safety featuresand generous provision of diagnosticinformation.

The rugged STNRG ICs contain ST’s uniqueState Machine Event Driven (SMED) high-resolution PWM generator, together with an 8-bit supervisory controller core. The SMEDcircuitry is a proven method for implementinghigh-performance digital control in STLUX ICsfor LED lighting.

The STNRG parts also include a 32kbyteEEPROM, 6kbyte RAM, an ADC, op amp, I2Cport and general-purpose I/Os.

Configuring the SMED calls for no specialistsoftware expertise, unlike the usual DSP- ormicrocontroller-based approaches to digitalpower control.

The SMED can be triggered from the internaltimer or by an external event such as peakcurrent, over-current or zero crossing. This enables a peak-current detecting buckconverter, with constant off-time set by thetimer, to operate without intervention by the coreprocessor. A simple proportional-integral loopexecuted in the core sets the peak-currentvalue for output regulation.

The STNRG family is comprised of theSTNRG288A with four SMED-controlledoutputs, the STNRG328A with five SMEDoutputs, and the STNRG388A with six SMEDoutputs. Designers have the option to connecttwo SMED cells together to generate dualgate-drive signals with inserted dead time forhalf-bridge configurations.

SL POWER

STMICROELECTRONICS

APPLICATIONS• Test and measurement equipment• Industrial equipment

FEATURES• Input-voltage range: 90-264V AC• Three-year warranty• Approved to EN/IEC/UL 60950-1,

2nd Edition, Am. 2• <1s turn-on time at 115V AC• >20ms hold-up time• ±5.0% total regulation • Operating temperature range:

-20°C to 50°C


APPLICATIONS• High-end industrial applications • Solar-power converters• Electric-vehicle charging stations• Industrial switched-mode power supplies

FEATURES• Four analogue comparators• <50ns propagation delay• Internal 96MHz PLL• System, auxiliary and basic timers• Multiple low-power modes • UART interface • I2C master/slave interface • Operating-temperature range:

-40°C to 105°C




SL Power’s TE60 series: no-load power consumption below 0.21W

Low common-mode noise, level 4 ESDprotection (compliant with IEC 61000-4-2:8kV/15kV) and surge protection (compliant withIEC 61000-4-5: 1kV differential mode/4kVcommon mode) help to ensure the highestoverall performance.

The TE60 power supplies offer regulatedoutput power with low ripple, no-load powerconsumption of less than 0.21W, and short-circuit and thermal protections. They meet therequirements of the EN55011/CISPR11, FCCPart 15.109 Class B standard for conducted

The EVLSTNRG-170W evaluation board is intended forevaluating the STNRG388A digital controller in off-linepower-conversion applications. The board implements aPFC stage followed by a resonant LLC stage, supplying aload of up to 170W. Orderable Part Number: EVLSTNRG-170W

FREEBOARDS

Apply now at my-boardclub.comFast-track board request code: FTM61AST’s STD16N60M2: page 24PARTNERWORKING



Hybrid energy-storage capacitorscombine high density and low profile

Vishay Intertechnology has introduced anew series of ENYCAP™ hybrid energy-storage capacitors with low 2.5mmprofiles which feature industry-highenergy density of 13Ws/g.

The Vishay BCcomponents196 HVC ENyCAP series isavailable in versions with upto six cells and capacitancevalues from 4F to 90F.Stacked through-hole,surface-mount flat and lay-flat configurations featurepins, tabs, and connectors.Voltage ratings start at 1.4Vfor a single-cell configuration,and also include 2.8V, 4.2V,5.6V, 7.0V and 8.4V versions(with multiple cells).

Its unique technology,which requires no cellbalancing, provides softcharging characteristics.

VISHAy

APPLICATIONS• Back-up power for data-storage

applications• Power-failure and write-cache protection

for hard disk drives• Power sources for real-time clocks • Burst-power support for flash lights and

wireless transmitters• Back-up power for industrial PCs and

industrial control systems• Storage device for energy-harvesting

systems

FEATURES• Non-hazardous electrolyte• Maintenance-free, no service necessary


New power MOSFETs get close toperfect switching performance

STMicroelectronics has extended itspopular MDmesh™ M2 series of N-channel power MOSFETs with theintroduction of a new family of deviceswhich offer the industry’s highestpower efficiency, especially underlight-load conditions.

With these new devices, designers can createswitching power-conversion circuits which arelighter and more compact, while more easilymeeting increasingly stringent energy-efficiencytargets.

The new 600V MDmesh M2 EP devicescombine ST’s proven strip layout with a newimproved vertical structure and an optimiseddiffusion process to produce performanceclose to that of the ideal switch: they combinevery low on-resistance and the lowest knownturn-off switching losses.

The MDmesh M2 EP MOSFETs are tailoredfor very high-frequency converters switching athigher than 150kHz.

Ideal for both hard- and soft-switchingtopologies, including resonant topologies suchas LLC, the new devices offer extremely lowswitching losses, especially under light-loadconditions.

In addition to the very low gate chargefound in all MDmesh M2 devices, the M2 EPdevices also feature up to a 20% reduction in

turn-off energy, thus reducing by the samepercentage the turn-off switching losses inhard-switching converters. This reduction inthe low-current range boosts efficiency underlight-load conditions, where efficiencyreuglations are becoming increasinglydemanding.

The enhanced shape of the turn-offwaveforms leads to higher efficiency and lowernoise in resonant converters, allowing moreenergy to be stored and re-used, rather thandissipated as heat, cycle by cycle.

STMICROELECTRONICS

APPLICATIONS• Servers• Laptops• Telecoms equipment• Consumer devices

FEATURES• Extremely low gate charge • Excellent output-capacitance profile • 100% avalanche-tested • Zener-protected




Orderable Part Number: MAL219699001E3

FREEBOARDS


ENyCAP capacitors: no cell balancing required

The low leakage current after 24 hours is in arange from 0.03mA to 0.5mA.

For technical evaluation, Vishay provides acomplete development kit. This demonstrates acomplete 20V/1A buck DC-DC and back-upregulator with integrated ENyCAP charger,charge-current monitor, integrated timer anddeep-discharge load-switch protection.

The devices offer a useful life of 1,000 hoursat 85°C.

ST’s STNRGxxxA: page 23PARTNERWORKING

Future Electronics’ Board Club: supporting innovative electronics designEurope’s electronics industry thrives on the application of innovation and creativity, and an essentialinnovator’s tool in design projects is the development board. The Board Club website is a Future Electronicsresource for users of development boards. Here, and only here, Board Club members can gain access toexclusive 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

B O A R D S O F T H E M O N T H

25

APPLICATIONS• Factory automation• Security equipment• Servers and data centres• Switches and routers• LED panels

FEATURES• High light-load efficiency • Supports pre-bias output with soft-start• External frequency synchronisation• Power Good indicator• Back-biased from output to improve

efficiency


ISL8117 eval boards: accept input voltages up to 60V

New evaluation boards for 60Vsynchronous step-down PWM controller

The ISL8117EVAL1Z and ISL8117EVAL2Zdevelopment boards enable designers toevaluate the performance of the ISL8117,a 60V synchronous buck controller fromIntersil.

The ISL8117 offers external soft-start andindependent enable functions, and integratesvarious circuit-protection features. Its current-mode control architecture and internalcompensation network keep peripheralcomponent count to a minimum.

The device’s programmable switchingfrequency, which ranges from 200kHz to2MHz, gives the designer the flexibility tooptimise the balance between inductor size,power consumption and noise.

Both the ISL8117EVAL1Z and ISL8117EVAL2Zevaluation boards are designed for high-currentapplications, and accommodate a wide input-voltage range of 4.5V to 60V, in the case of the

ISL8117EVAL1Z, and 18V to 60V for theISL8117EVAL2Z.

The current rating of the ISL8117EVAL2Z islimited by the FETs and inductor selected. TheISL8117 gate driver is capable of delivering upto 20A for the buck output as long as theproper FETs and inductor are provided.

INTERSIL


APPLICATIONS• Consumer devices• Industrial control equipment • PC peripherals

FEATURES• Camera extension headers• 10/100 Ethernet PHy• On-board power regulation via 3.3V LDO• One Reset and one unassigned push

button• Green user LED


Board with multiple connection optionssupports latest Atmel SAM x70 MCUs

The Atmel® | SMART™ SAM E70 Xplainedevaluation kit is ideal for evaluating andprototyping with the Atmel SAM S70 andSAM E70 microcontrollers, which arebased on the ARM® Cortex®-M7processor core.

The evaluation board includes anATSAME70Q21 MCU, which is housed in a144-lead LQFP package, an AT24MAC402EEPROM and a 16Mbit IS42S16100E SDRAMmemory IC.

The ATSAME70Q21 with a floating point unitoperates at up to 300MHz and features2Mbytes of Flash memory. It offers variousnetworking and connectivity peripherals,including a CAN-FD interface and one10/100Mbits/s Ethernet MAC, with specific

hardware support for Audio Video Bridging(AVB). Analogue features include dual2Msamples/s 12-bit ADCs with an analoguefront end offering offset and gain-errorcorrection, and a 1Msample/s 12-bit DAC.

The evaluation board’s connectivity optionsinclude a 4-bit SD card connector, a Micro-ABUSB device connector and a Micro-AB USBdebug interface. The board also containsvarious headers for extension boards, whichmay be purchased individually.

ATMEL


Orderable Part Number: ATSAME70-XPLD

FREEBOARDS


Orderable Part Numbers:

ISL8117EVAL1Z and ISL8117EVAL2Z

FREEBOARDS


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

Silicon Carbide (SiC), a wide bandgap material with markedlysuperior characteristics to silicon in high-voltage circuits, hasstruggled to gain widespread market acceptance. In someways, this is surprising: SiC components – diodes andMOSFETs – are ideal for high-voltage applications in whichenergy efficiency is a critical parameter.

For example, in solar inverters switching losses may be reduced bymore than 30% through the use of SiC MOSFETs. Solar inverters withboth SiC MOSFETs and diodes have been shown to be capable ofachieving overall system efficiency of greater than 99%.

Similar efficiency benefits can be achieved in other applications thatrequire high blocking voltages in combination with fast, efficientswitching: industrial motor drives, DC power systems in data centres,power factor correction circuits, and high-frequency DC-DC convertersin industrial, computing and communications power systems. Benefittingfrom low switching losses, SiC MOSFETs and diodes can enableoperation at switching frequencies up to four times higher than thoseusing conventional silicon IGBTs.

So why are SiC components not in widespread use in theseapplications? The answer is simple: component cost. An expensivemanufacturing process means that the cost of a SiC MOSFET is farhigher than that of a comparable silicon component. Simply replacing asilicon MOSFET or IGBT in a conventional power circuit with a SiCMOSFET normally makes little financial sense.

But this is the wrong way to approach power-system design with SiCcomponents. In fact, the proper use of SiC components can result inlower total system costs, despite the relatively high cost of the SiCcomponents. But if design engineers are to realise cost savings from theuse of SiC technology, they must thoroughly review and modify theirexisting circuits, and possibly even abandon an existing design entirelyand start afresh. This article shows why.

The cost contributors in a high-voltage power circuitThe reason the power-system designer should not focus on a simplecost comparison of silicon and SiC components is that thesecomponents make up only a small proportion of the total system cost. Infact, the main cost contributors to a high-voltage circuit are: • Power semiconductors• Heat-sink• Transformers• Inductors• Capacitors• PCB

In addition, in some end-product types there might be noticeable costsassociated with transport or handling of the end-product. In thesecases, the weight and size of the power circuit can have a markedimpact on the manufacturer’s costs.

When a circuit is designed from the start with the intention of usingSiC MOSFETs and diodes, savings can be made in every one of thecost contributors listed above. As a result, design teams that havedesigned new power circuits to take full advantage of SiC technology

are gaining a distinct competitive edge. For example, motor-systemmanufacturer Kollmorgen (www.kollmorgen.com) has developed aprototype of a new SiC-based inverter, as shown in Figure 1, for use inheavy-duty Hybrid Electric Vehicles (HEVs) such as city buses.

Specified for operation at 750V DC and 400Arms, the SiC version ofthe inverter offers the following advantages over the equivalent productthat uses silicon IGBTs: • 1% superior system efficiency, the equivalent in a typical city bus to an

annual reduction in fuel consumption of between 600 litres and 1,000litres of diesel fuel

• A much cheaper thermal design using air cooling rather than watercooling

• Higher-frequency switching, enabling the use of smaller passivecomponents

According to Lux Research (www.luxresearchinc.com), the savings infully Electric Vehicles (EVs) look equally promising. Attempts to extendthe performance of silicon devices in high-voltage applications are hittingthe physical limits of the material’s characteristics. In an August 2014paper, the researchcompany found that the useof Wide Bandgap (WBG)materials such as SiC offerseconomic benefits becauseof the large batteries in EVs,as shown in Figure 2.

‘Efficient powerelectronics is key to asmaller battery size, whichin turn has a positivecascading impact on wiring,thermal management,packaging and weight ofelectric vehicles,’ said PallaviMadakasira, an analyst at Lux Research and the lead author of thereport titled Silicon vs WBG: Demystifying the Prospects of GaN and SiCin the Electrified Vehicle Market.

On the Tesla Model S for example, a 20% reduction in power use canmake the battery system $6,000 cheaper – some 8% of the vehicle’stotal cost.

According to Lux Research, a power saving of just 2% makes the useof SiC diodes essential in EVs, on the assumption that battery costs fallbelow $250/kWh. For plug-in HEVs, the threshold for the introduction of

SiC components is a5% power saving.

To illustrate the waythat SiC componentsenable cost savingsacross the whole of apower circuit, let usstudy an example, anapplication that hasbeen developed by a

Fig. 1: Kollmorgen’s SiC inverter prototype has no need for an expensive liquid cooling mechanism(Source: Kollmorgen)

How to reduce the total cost of a power

EMAIL [email protected] FOR SAMPLES AND DATASHEETS26

Fig. 3: Architecture of the STMicroelectronics 5kW boost-convertercircuit (Source: STMicroelectronics)

READ THIS ARTICLE TO FIND OUT ABOUT• Why the use of expensive SiC power components can result in

lower system costs• Examples of design implementations which have realised

performance and cost improvements by replacing silicon IGBTs withSiC MOSFETs

• The prospects for wider adoption of SiC power components as theirprices fall

By Erich NiklasRegional Sales Manager (Central Europe), Future Power Solutions

Fig. 2: The dramatic power efficiency gains offered by SiCdevices will help to slash the cost of electric and hybridelectric vehicles. (Source: Lux Research)

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

and size provided in adesign based on SiCcomponents come inaddition to the bill-of-materials cost savings.

Another example ofthe benefits that SiCcomponents will bringto the fast growing EVmarket was presentedby car manufacturerToyota at theAutomotive Engineering

Exposition (May 2014, Japan). Toyota estimates that 20% of totalelectrical power losses in HEVs are attributable to powersemiconductors. Improving the efficiency of the power semiconductorsdirectly reduces fuel consumption.

Toyota has set a goal of achieving a 10% improvement in HEV fuelefficiency: SiC MOSFETs supplied by Microsemi are now playing a role inits strategy for achieving this goal.

Results from development work carried out by Toyota show thatpower losses when using SiC MOSFETs are around 10% of the powerloss suffered by Si IGBTs. In addition, the switching frequency can beincreased by a factor of ten, which enables a reduction in the size of thepower control unit of around 80%.

There is a commercial as well as an engineering benefit to the use ofSiC MOSFETs in HEV power supplies. Toyota presented a costcomparison for a three-phase 225kW inverter for an electric vehicleusing a 350V battery. Toyota’s current solution uses 84 Si IGBTs. Thegoal was to replace these with SiC MOSFETs in order to improve systemperformance at a total cost no higher than that of the current design.

The design uses 60 SiC MOSFETs supplied by Microsemi, rated for amaximum voltage of 700V and with typical on-resistance of 40mΩ. Itreduces the cost of the battery by 6%, and the magnetics by almost50%, while the passives and other components have almost the samecost as the IGBT solution. Although the cost of the semiconductors isthree times higher than that of the IGBT design, the total system cost is5% lower.

And, as Figure 8shows, the SiCMOSFET system has aparticularly markedefficiency advantageover the IGBT systemat low loads.

A fast-changingmarket The examplesdescribed abovesuggest that thecost/performance battle between SiC MOSFETs and IGBTs is finelybalanced today. As the months go by, however, the balance will continueto tip further and further in the SiC components’ favour, because ofexpected steep falls in the price of SiC MOSFETs. This price drop is dueto increased competition among wafer suppliers and the transition to a6” wafer fabrication process.

As the basic price of SiC components falls, the benefits to be gainedfrom designing systems around them become even more attractive. Formanufacturers of solar inverters, as well as many other types of high-power equipment, a tipping point might now have been reached, atwhich silicon carbide becomes the favoured material for switchingcomponents.


circuit with the use of SiC componentsresearch team at STMicroelectronics. The prototype developed by ST isa 5kW boost converter, a functional block in a solar inverter, as shown inFigure 3. The prototype uses the following SiC components:• The SCT30N120 is a 1,200V SiC N-channel power MOSFET. It is

rated for operation across a junction temperature range of -55°C to200°C. On-resistance is rated at a typical 80mΩ.

• Two STPSC6H12 1,200V SiC Schottky diodes functioning as arectifier.

The system is designed to boost a 400-600V DC input to 800V DC incontinuous-current mode, supportingan output power of 5kW. The SiCMOSFET’s maximum junction-temperature rating is some 25°Chigher than that of a comparablesilicon IGBT, which means that asmaller heat-sink can be used, asshown in Figure 4.

The boost inductor is rated for amaximum 25A current, with lowparasitic capacitance and a 25Asaturation current.

STMicroelectronics evaluatedcomparable systems at switchingfrequencies of 25kHz (the limit of a

silicon IGBT’s performance in this application) and 100kHz (with a SiCMOSFET), to examine the trade-off between cost and performance.

Increasing the switching frequency allows for the use of a smallerinductor and/or a smaller output capacitor. Technically, given that themaximum current ripple occurs at Vin=Vout/2, the higher the switchingfrequency the lower the inductance required, according to the formula:

Figure 5 shows the reduction in the size and weight of the inductorachieved by operating at the high 100kHz frequency supported by thefast SiC components.

A summary of the superior performance achieved by the SiC-baseddesign is shown in Figure 6: with a SiC MOSFET, the system switchesfour times faster and offers higher efficiency, and uses smaller and lightermagnetics and heat-sink.

Even moreinteresting,Figure 7’s costcomparisonshows that,even thoughthe SiCMOSFET isnine times

more expensive than a silicon IGBT, the total system cost is lower in adesign that takes full advantage of the SiC MOSFET’s superiorcharacteristics. This is because the inductor, capacitor and heat-sink areexpensive components. Moreover, the benefits of the reduction in weight


Fig. 8: Efficiency comparison in HEV inverter, SiC MOSFET vs Si IGBT

Fig. 4: A SiC MOSFET requires a smallerheat-sink than the equivalent Si IGBT (Source: STMicroelectronics)

Fig. 5: Size and weight comparison of inductor required when switching at 25kHz and 100kHz (Source:STMicroelectronics)

Parameters ƞ% @5kW

Ferrite CoreInductorVolume (L)

Ferrite CoreInductor

Weight (kg)

Heat-sinkRth (°C/W)

SiC MOSFET @ 100kHz 98.17 0.78 1.35 0.65

IGBT @ 25kHz 98.13 1.45 3.4 0.53

4kW Boost ConverterVin= 600V, Vout = 800V

IGBT + SiC Diodefsw = 25kHz

SiC MOSFET +SiC Diode fsw = 75kHz

Inductor 58% 45%Capacitor 15% 9%Heatsink 17% 8%IGBT/SiC MOSFET 4% 32%SiC Diode 6% 6%Efficiency 98.6% 99.1%Normalised Total 100% 95%

Fig. 6: Comparison of performance and component requirements of SiC andIGBT-based designs (Source: STMicroelectronics)

Fig. 7: SiC MOSFET v Si IGBT cost comparison for a 5kWconverter design, showing normalised percentage of BoM costcontributed by each component type (Source: STMicroelectronics)

power management · digital gas sensor offers low power consumption cambridge cmos sensors (ccs)...

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