dual battery require bi-directional dc/dc controllers · of compound semiconductors. silicon...

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CONTENTS

www.power-mag.com Issue 1 2017 Power Electronics Europe

3

Editor Achim ScharfTel: +49 (0)892865 9794Fax: +49 (0)892800 132Email: [email protected]

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ISSN 1748-3530

PAGE 6

Evolving Technologies

PAGE 8

Market News

PEE looks at the latest Market News and company developments

PAGE 14

APEC 2017

PAGE 16

Industry News

PAGE 23

PCIM 2017

PAGE 26

Benefits of Direct 48 V / 1 VConversionIn data centres and telecom offices, the most important issues affecting decisionsabout power supply design are usually cost, efficiency, and the available boardreal estate. Typical early power distribution strategies utilized multiple isolatedquarter brick or eighth brick converters to convert from a bus voltage – usually 48V – to the required IC supply voltage, at the point of load. A new generation ofsingle-stage converters is set to emerge, to convert down from 48 V directly tologic voltages at high efficiency and within compact dimensions. Bob Cantrell,Senior Application Engineer, Ericsson Power Modules, USA

PAGE 31

ProductsProduct update

PAGE 33

Website Product Locator

Dual Battery Require Bi-Directional DC/DCControllersWith fuel economy regulations tightening andautonomous-driving capability with connectivityproliferating, the old-fashioned 12 V automotiveelectrical system has reached its usable power limit.Furthermore, a vast increase in automotive electronicsystems, coupled with related demands on power, hascreated an array of new engineering opportunities andchallenges. As a result, the 12 V lead-acid batteryautomotive system with its 3 kW power limit has beensupplemented. A newly proposed automotivestandard, LV148, combines a secondary 48 V bus withthe existing 12 V system. The 48 V rail includes anintegrated starter generator (ISG) or belt startgenerator, a 48 V lithium-ion battery and a bi-directional DC/DC converter for delivery of up to 10kW of available energy from the 48 V and 12 Vbatteries combined. This technology is targeted atconventional internal combustion automobiles, as wellas hybrid electric and mild hybrid vehicles, as automanufacturers strive to meet increasingly stringentcarbon dioxide emissions targets. More details on page 28.

Cover photo supplied by Linear Technology, USA

COVER STORY

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OPINION 5


The total market for automotive power semiconductors (discretes,power modules and power ICs) will increase from $5.5 billion in2016 to more than $8.5 billion in 2022. Revenue will grow at anannual rate of 7.5 percent from 2015 to 2022, increasingelectrification in vehicles generally – and in hybrid and electricvehicles specifically – is energizing the market for powersemiconductors in vehicles, market researcher IHS predicts.Anticipated growth in sales of hybrid and electric vehicles in thenext few years will spur power semiconductor sales to climb byCAGR 9.6 percent from 2015 to 2022 across all vehicles, takingPowertrain’s market share up to 54 percent of the total market.Discrete IGBT power transistors account for most of Powertrainpower semiconductor revenue, but increased integration ofdiscretes into modules will cause IGBT power module sales toincrease at a much faster rate. Demand for hybrid and fully electric vehicles was extremely

encouraging worldwide in 2016. That applies especially to China,which is now the biggest market for electromobility. Theassociation of Chinese vehicle manufacturers forecasts sales ofaround 400,000 so-called “new energy vehicles” in total in 2016,an increase of roughly 20 percent. At Infineon the Automotive segment generated revenue of

€2.651 billion in 2016, an increase of 13 percent over theprevious year. Power semiconductors play a major technologicalrole in limiting global warming to well below two degrees.Compound semiconductors, especially those made of SiliconCarbide, will enable more energy-efficient solutions in the future.This applies in particular to electromobility and the generation ofrenewable energies. The planned acquisition of Cree/Wolfspeed

will enhance our portfolio with know-how and products in the fieldof compound semiconductors. Silicon Carbide has a hugepotential in order to increase efficiency of the inverters used inelectromobility. Here Infineon will set a focus on their 1200 V SiCTrench MOSFETs introduced at PCIM 2016 and in particular onhigher battery voltages around 800 V such as proposed byPorsche with the Mission E sportscar. But this possible business is only a small fraction of the EV

market, the main music will be played in mild hybrid electricvehicles. A first step towards automotive electrification respectivehybridization is been seen in the move to a 48 V board net. By2020, automotive 48 V systems will help reduce emissions by upto 15 percent, improve fuel consumption, capture energy typicallylost while braking, and provide torque in the low RPM range forstart-stop mild hybrids. The 48 V power net is needed to managethe next generation of energy efficient electrical systems thatrequire more power than available with the existing 12 Vsubsystem. To reduce weight, many traditionallymechanical/hydraulic systems such as power steering, rollstabilization, heating, and air conditioning will be converted to 48 Velectrical drive. A new electric turbocharger will provide on-demand horsepower and torque, enabling the use of smaller moreefficient combustion engines without sacrificing drive ability. Ahigh-power starter/generator will replace the 12 V alternator,reducing noise and vibration during engine starting while allowingregenerative braking to recapture up to 4x more of the availablekinetic energy. The 12 V bus and 12 V lead-acid battery will handlethe lighter loads, including ignition, interior lighting, navigation andaudio systems.According to the author of our cover story, the 12 V bus will

continue to power the ignition, lighting, infotainment and audiosystems. The 48 V bus will supply active chassis systems, airconditioning compressors, adjustable suspensions, electricsuperchargers/turbos and also support regenerative braking. Thedecision to use an additional 48 V bus, which is expected beavailable across production model ranges soon, can alsosupport starting the engine, which would make stop-startoperation smoother. Moreover, the higher voltage means smallercable cross-sections are needed which reduces cable size andweight. Today’s high-end vehicles can have more than 4kilometers of wiring. Vehicles will become more like PCs, creatingthe potential for a host of plug-and-play devices. On average,commuters spend nine percent of their day in an automobile.Thus, introducing multimedia and telematics into vehicles canpotentially increase productivity as well as providing additionalentertainment. The key components for autonomous drivinginclude a computer, cameras, radar and LiDAR sensors, all of whichrequire additional energy. This additional energy is required toimprove vehicles’ connectivity, not just to the Internet, but to othervehicles and buildings, traffic signals and other structures in theenvironment. Furthermore, drive train components, power steering,oil and water pumps will switch over from mechanical to electricalpower. All these applications will lead to more power electronics in the

automobile – good prospects for this industry in 2017.

Enjoy reading the content of this issue!Achim Scharf

PEE Editor

Powering theAutomotive Industry

05_PEE_0117.qxp_p05 Opinion 09/02/2017 09:25

6 EVOLVING TECHNOLOGIES

Issue 1 2017 Power Electronics Europe www.power-mag.com

The Open Compute Project is an organization thatshares designs of data center products amongcompanies, including Facebook, Intel, Nokia,Google, Apple, Microsoft, Seagate Technology, Dell,Rackspace, Ericsson, Cisco, Juniper Networks,Goldman Sachs, Fidelity, Lenovo and Bank ofAmerica. The Open Compute Project’s mission isto design and enable the delivery of the mostefficient server, storage and data center hardwaredesigns including power supply.

The OCP initiative (www.OpenComputeProject.org) was announced in April 2011 byFacebook to openly share designs of data centertechnology due to a redesign of Facebook’s datacenter in Prineville, Oregon. One step was toimprove the energy efficiency, as measured by thepower usage effectiveness index. Power usageeffectiveness (PUE) is a measure of how efficientlya computer data center uses energy; specifically,how much energy is used by the computingequipment (in contrast to cooling and otheroverhead). PUE is the ratio of total amount ofenergy used by a computer data center facility tothe energy delivered to computing equipment, inother words it is the inverse of data centerinfrastructure efficiency (DCIE). An ideal PUE is1.0. Anything that isn’t considered a computingdevice in a data center (i.e. lighting, cooling, etc.)falls into the category of facility energyconsumption.Google (www.google.com) joined the OCP

early last year to help drive standardization in ITinfrastructure. More specifically, Google iscollaborating with Facebook on a new rackspecification that includes 48 V power distributionand a new form factor to allow OCP racks to fitinto their data centers. John Zipfel, TechnicalProgram Manager at Google, detailed at the 2016OCP Summit this attempt: “Energy efficiency in

computing is a topic that has been near and dearto our hearts since the early days. We beganadvocating for efficient power supplies in 2003,and in 2006 shared details of our 12-voltarchitecture for racks inside our data centers — theinfrastructure that supports and powers rows uponrows of our servers. In 2009, we started evaluatingalternatives to our 12 V power designs that coulddrive better system efficiency and performance asour fleet demanded more power to support newhigh-performance computing products, such ashigh-power CPUs and GPUs. We kicked-off thedevelopment of 48 V rack power distribution in2010, as we found it was at least 30 % moreenergy efficient and more cost effective insupporting these higher-performance systems. Our48 V architecture has since evolved and includesservers with 48 V to point-of-load designs, andrack-level 48 V Li-Ion UPS systems. Google hasbeen designing and using 48 V infrastructure atscale for several years, and we feel comfortablewith the robustness of the design and its reliability.As the industry’s working to solve these sameproblems and dealing with higher-powerworkloads, such as GPUs for machine learning, itmakes sense to standardize this new design byworking with OCP. We believe this will helpeveryone adopt this next generation powerarchitecture, and realize the same power efficiencyand cost benefits as Google.” More can beexpected at the 2017 OCP Summit in March.

Long history in telecommsMark Murrill and B.J. Sonnenberg, EmersonNetwork Power(www.EmersonNetworkPower.com) supportedin their White Paper “Evaluating the Opportunity forDC Power in the Data Center” Google’s approach. The dramatic increase in data center energy

consumption created both financial and

environmental challenges. Energy costs, whichonce had been relatively inconsequential to overallIT management, became more significant as therise in consumption was exacerbated by a steady—and in some years significant— increase in the costof electricity. In addition, increased awareness ofthe role that power generation plays inatmospheric carbon dioxide levels prompted theUS EPA to investigate large energy consumerssuch as data centers. In 2007 the EPA presented areport to the US Congress that includedrecommendations for reducing data center energyconsumption. 48 V power delivery has a longhistory in telecommunications. It is inherentlysimple and reliable with few conversion stages tothe point-of-load. Already in Bell’s days 48 V DCwas chosen as a standard for two reasons: DCpower was felt to be more reliable than ACbecause it could be directly connected to back-upbatteries, and 48 V was considered the optimaltrade-off between transmission distance andhuman safety. Today, the authors claim that theideal point for power conversion is as close to thepoint-of-load. Global data center/cloud power market is

exploding at over 10 percent annually to anestimation of 2 trillion kWh by 2020. Efficientpower delivery from utility to the point of loadcould result in an astronomical amount of energyand expenditure savings. Today’s datacenterpayloads generally use traditional 12V for sub-rackpower distributions, but the exponentiallyincreased distribution losses jeopardizes efficiencyand scalability as power grows rapidly. Google hasdeployed a compelling 48V rack ecosystem in itsdata centers for several years, which promised toprovide better efficiency, performance andscalability for more power-hungry computingsystems enabled by high-end CPUs, acceleratorsand ASICs. Thus the 48 V to point-of-load

Emerging Power Delivery Standard 48 V for Data Centers

48 V DC power supply as typically implemented in telecommunications central offices

Technologies.qxp_Layout 1 09/02/2017 08:53

EVOLVING TECHNOLOGIES 7


conversion technology is one of the key enablers. Although the benefits of a higher distribution

bus voltage, particularly 48 V, which requires nospecial safety precautions, are well known (smallercables and bus bars, lower distribution losses,smaller storage capacitors), conventional powerconversion approaches have not been able toefficiently, or compactly, transform power from a48 V bus into the low voltages (e.g., 3.3 V, 1.8 Vand 0.8 V) and high currents (e.g. 95 A) requiredby contemporary CPUs or GPUs. As a result, CPUpower conversion has customarily relied on 12 Vdistribution. A 12 V bus, however, must carry fourtimes the current carried by a 48 V bus, and,because distribution losses are a function of thesquare of the current, the power lost in a 12 V buscan be as much as 16 times the loss in a 48 Vbus. By providing efficiencies from a 48 V bus thatare better than 12 V legacy solutions, in a fractionof the space, Thus 48 V direct-to-PoL conversioneliminating an intermediate 48 V / 12 Vconversion step enable system designers toimplement green distributed system solutionsfeaturing high conversion efficiency, high powerdensity and low distribution loss.

Direct Conversion from 48 VThus direct conversion 48 V / 1 V is becoming a

hot topic, i. e. at this year’s APEC. Here Dr. ShuaiJiang and Xin Li, Google, Technical Lead Managerfor Power Team and Sr. DC/DC Power Architectfor Data Centers, Google 48V Power Architecture,will emphasize the latest achiements in theplenary speech (see our APEC preview in thisissue).At the International Electron Device Meeting

(www.IEDM.org) in December 2016 Alex Lidow,CEO of Efficient Power Conversion (www.EPC-Co.com) gave a paper “System Level Impact ofGaN Power Devices in Server Architectures”. Newpower system architectures for 48 V – 1Vconversion have grown in importance as powerdensities in server farms increase at a quickeningpace due to applications such as deep learningand artificial intelligence. Four architectures wereexamined in this paper – each with relativestrengths and weaknesses – but all of the GaN-based solutions demonstrate efficiency and powerdensity exceeding today’s silicon-based solutions.A non-isolated two-stage converter had the highestpower density, lowest acquisition cost, fastesttransient response, and second-best efficiency. Ifefficiency is paramount, a one stage transformer-based solution can achieve up to 90 % efficiency,but with a sacrifice in cost, density, and transientresponse. Though GaN technology, being in its

infancy, it is improving at a much faster pace thantheir aging semiconductor ancestor and thereforeforward thinking designers can create products thatcontinuously keep up with the ever-increasingdemands of the information age.According to Ericsson (see our feature in this

issue), a new generation of single-stage convertersis set to emerge, to convert down from 48 Vdirectly to logic voltages at high efficiency andwithin compact dimensions. The converters will becapable of supporting the low duty cycles requiredto convert from, say, 48 V to 1.0 V, while operatingat a high switching frequency to ensure fasttransient response and minimize reliance ondecoupling capacitance and magneticcomponents. The adoption of direct conversion,implemented using the latest power technologies,is an emerging trend. The industry needs toidentify the sweet spot as far as specifics such asmodule current ratings or power delivery areconcerned. Direct conversion is expected to deliverthe greatest efficiency gains in equipment at higherpower levels, and can be used to dramaticallyreduce loads in Intermediate Bus Convertersthereby allowing smaller IBCs; possibly downsizingthese from quarter brick to smaller eighth brickunits. This should be ideal for next-generationhigh-current processors. AS

ABOVE: Block diagrams of four different 48 V / 1 V DC/DCconversion

LEFT: Efficiency of four power system topologies for VIN=48 V toVOUT=1 V (the dotted line represents a Silicon-basedimplementation of architecture A in the figure left)

Technologies.qxp_Layout 1 09/02/2017 08:53

8 MARKET NEWS

Power Semiconductors in AutomotiveRamp Up $8.5 Billion by 2022The global market for power semiconductors usedin cars and light passenger vehicles will grow bymore in $3 billion in the next five years, due to bigjump in electrification of vehicles.According to new analysis by IHS Markit

(www.ihsmarkit.com). the total market forpower semiconductors (discretes, power modulesand power ICs) will increase from $5.5 billion in2016 to more than $8.5 billion in 2022. Revenuewill grow at an annual rate of 7.5 percent from2015 to 2022, the report “Power Semiconductorsin Automotive – 2017”, predicts. “Increasingelectrification in vehicles generally – and in hybridand electric vehicles specifically – is energizing themarket for power semiconductors in vehicles”, saidRichard Eden, senior analyst, powersemiconductors for IHS Markit. “Staying connectedvia smartphones and tablets is the modern way oflife and to this end, today’s car drivers are optingfor Bluetooth, cellular technologies and othertelematics functions. All these features requirepower semiconductors to distribute and controlpower through vehicles.” Also contributing to therise of power semiconductors, the report notes, is

the automotive industry’s mission to offer self-driving, ‘green’ and connected cars in the nextdecade. “Intermediate safety milestones such asautomatic emergency braking (AEB) andplatooning are necessary to realize a road systemthat will accommodate self-driving cars. Otherfactors in the trend toward more powersemiconductors: the need for more fuel-efficientsystems, a higher proportion of electric vehicles,and more electronic content per vehicle asrequired for improved vehicle emission levels”,Eden noted. IHS Markit categorizes five domains on a

vehicle: Body and Convenience, Chassis andSafety, Infotainment, Powertrain and AdvancedDriver Assistance Systems (ADAS). Of these,Powertrain accounted for 47 percent of the totalmarket for automotive power semiconductors in2015, the report indicated. Anticipated growth insales of hybrid and electric vehicles in the next fewyears will spur power semiconductor sales to climbby CAGR 9.6 percent from 2015 to 2022 acrossall vehicles, taking Powertrain’s market share up to54 percent of the total market. Discrete IGBT

power transistors account for most of Powertrainpower semiconductor revenue, but increasedintegration of discretes into modules will causeIGBT power module sales to increase at a muchfaster rate. The Chassis and Safety category represents the

second most-valuable automotive domain forpower semiconductors, accounting for 24 percentof the total market in 2015. In contrast withPowertrain, the use of power semiconductors inChassis and Safety will only grow with CAGR of3.1 percent from 2015 to 2022, the report says.The biggest user of power devices in this domainare applications such as electric power steering,anti-lock braking system and electronic stabilitycontrol, airbags and tire pressure monitoring,which are already relatively well-established invehicles.The domains of Body and Convenience and

Infotainment only accounted for 14 percent and11 percent of the total automotive powersemiconductor market in 2015, respectively. Bothcategories are expected to grow with a CAGR ofaround 4 to 5 percent from 2015 to 2022, the

Market news.qxp_Layout 1 09/02/2017 09:51

MARKET NEWS 9

Estimated total market fordiscrete powersemiconductors, powermodules and power ICseach year divided by thetotal number of lightvehicles produced in eachyear

Source: IHS Markit 2017

report predicts. At present, the smallest domain isADAS, with only 5 percent of the total market in2015. However, ADAS is forecast to see the fastestgrowth of all of the five domains, growing with aCAGR of 16 percent from 2015 to 2022. ADAS willsee a rapid increase in the number of sensors,cameras and interconnectivity systems in cars, andall will need power semiconductors in their power

control circuitry.Discrete power semiconductors, the report

points out, provide the highest average value percar. “This is not surprising as they have the lowestaverage sales price and are used in even thesimplest, cheapest automotive electronic systemslike engine, transmission control units, electrifiedoil pumps and power systems. Power ICs provide

slightly less average value per car. They are moreexpensive and newer, so are more prevalent inhigh-end vehicles and more modern car designs,which contain more features, like ADAS, forexample. Power modules have the smallestaverage value per car because their use isrestricted to larger, high-end vehicles and to hybridand electric vehicles only.


10 MARKET NEWS


In Fiscal year 2016 Infineon’s revenue rose byaround 12 percent to €6.473 billion. Organicrevenue growth from October 2015 to September2016 amounted to seven percent. That’s anoutstanding performance, since the entire globalsemiconductor market experienced virtually nogrowth at all during the same period. Now thecompany is favoring Silicon Carbide technology forelectromobility.Demand for hybrid and fully electric vehicles

was extremely encouraging worldwide in 2016.That applies especially to China, which is now thebiggest market for electromobility. The associationof Chinese vehicle manufacturers forecasts sales ofaround 400,000 so-called “new energy vehicles”in total in 2016, an increase of roughly 20 percent.“The rise in demand and the technicalperformance are also good for our business - at aleading Tier-1 supplier we secured a design-winwith our IGBTs for partially and fully electric cars,with revenue potential in the three-digit millionrange”, CEO Reinhard Ploss remarked. TheAutomotive segment generated revenue of€2.651 billion, an increase of 13 percent over theprevious year. In the meantime, solutions forelectromobility and advanced driver assistancesystems (ADAS) accounted for around 50 percentof the revenue growth in the Automotive segment.The segment result rose to €396 million, a marginof 14.9 percent. The growing spread of ADAS also led to a rise in

demand for Infineon‘s radar chips. Twodevelopments will ensure that sales figurescontinue to rise in the future: the increasing marketpenetration of radar-based assistance systems, andthe growing number of radar sensors per vehicle.

“In fiscal year 2016 we sold over 12 million of our77-gigahertz radar chips – more than in theprevious six years combined. In the current fiscalyear we expect to sell between 25 and 30 millionchips”, Ploss stated. “Power semiconductors play amajor technological role in limiting global warmingto well below two degrees. Compoundsemiconductors, especially those made of SiliconCarbide, will enable us to develop even moreenergy-efficient solutions in the future. This appliesin particular to electromobility and the generation ofrenewable energies. The planned acquisition ofCree/Wolfspeed will enhance our portfolio withknow-how and products in the field of compoundsemiconductors. It will enable us to serve growingmarkets such as electromobility, renewableenergies and cellular infrastructure more effectively.”With an electric drivetrain, the inverter controls

the electric motor. This is a key component in thecar as, similar to the Engine Management System(EMS) of combustion vehicles, it determinesdriving behavior. Not only does the inverter drivethe electric motor, it also captures energy releasedthrough regenerative breaking and feeds this backto the battery. As a result, the range of the vehicleis directly related to the efficiency of the maininverter. According to Ploss Silicon Carbide has ahuge potential in order to increase efficiency. The battery in an electric vehicle is useless

without a battery charger. With an on-boardcharger unit, the battery can be charged from astandard power outlet. Charging via the main gridcalls for design flexibility given the different voltageand current levels in different countries. Andcharging time is an important factor for car drivers.System designers are challenged to support varied

voltage and current levels while increasing powerdensity. The key success factors of on-boardcharging are efficiency and high power density fora small form factor. The long-term trend is movingtowards bi-directionality, where the charger alsofeeds power from the car to the smart grid.Thus an appropriate charging infrastructure is

critical to support the rapidly growing electricvehicles market worldwide. Infineon supports theglobal standardization of charging infrastructure forhybrid and electric vehicles by joining the globalCharging Interface Initiative e.V.(www.charinev.org). CharIN’s goal is to develop,establish and promote a world standard for acharging system for all kinds of battery-poweredelectric vehicles. Among its founding members aremajor automotive manufacturers.For the first quarter of the 2017 fiscal year the

company reported positive results, mainly diven bythe automotive sector. “We had a good start intothe new fiscal year,” Ploss stated. “Whereasrevenue in the Power Management & Multimarketand Industrial Power Control segments decreaseddue to seasonal factors, revenue generated by theAutomotive segment continued to rise by 2percent to €705 million, compared with €691million in the preceding quarter. Continued highdemand for driver assistance systems andproducts deployed in hybrid and electric vehiclesmore than offset slightly lower demand in otherproduct lines related to the seasonaldevelopment.”Based on an assumed exchange rate of $1.10

to the Euro, revenue growth for the 2017 fiscalyear is forecasted of around 6 percent. Accordingto Ploss the GaN business will ramp-up in DC/DC

converters, but is still in thestarting phase. Regardingtechnology, the focus now is onnormally-off from Infineon’spartner Panasonic with their X-GaN devices. Regarding SiliconCarbide, the acquisition ofWolfspeed is on track. “Weexpect to close this transactionin the first calendar quarter andto integrate Wolfspeed’stechnology and organizationwithin one year”, Plossunderlined. AS

www.infineon.com

Silicon Carbide SpursElectromobility

“Silicon Carbide has a huge potentialfor the automotive drive train inorder to increase efficiency”, statedInfineon’s CEO Reinhard Ploss at theelectronica 2016 AutomotiveConference Photo: AS


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12 MARKET NEWS


Alternative Battery Technologies to Li-Ion

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Today, there is a relatively large variety of differentbattery technologies that can challenge Li-ionbatteries such as NAS, Li-S, Na-ion, Mg-ion, Li-air,zinc-air and flow batteries, and LIC. Some of thesetechnologies are at the R&D stage and some arealready in commercial production. A new report entitled “Beyond Li-Ion Batteries:

Present & Future Li-Ion Technology Challengers” byYole Développement (www.yole.fr) estimatesthat the energy storage market for thesetechnologies reached $121 million in 2015 andwill grow up to $357 million by 2025, a CAGR of11.4 percent. “The main demand for present Li-ionbattery technology challengers will come via utility-size stationary battery energy storage”, stated DrMilan Rosina, Senior Analyst for Energy Conversion& Emerging Materials. “Future Li-ion challengersmust overcome formidable technology challengesin order to achieve better performance and costthan Li-ion batteries. In the short-term, Li-S

technology is considered the best candidate toreach sufficient technology maturity for widercommercial deployment. Li-ion battery cell supplyis already well-consolidated. Three leadingcompanies, Panasonic, LG Chem, and SamsungSDI continue to cement their position as cellsuppliers by building new production facilities anddeveloping new supply partnerships with EV/HEVmanufacturers. To oppose the established Li-ionindustry, challengers pursue different strategies.The safest approach involves companies focusingon one specific technology part which can beapplicable in different battery chemistries, forexample the improvement of lithium-metalelectrode during the battery charging/dischargingcycles.”Oxis Energy’s initial focus is on niche markets

where high energy density is a priority. The goal isto obtain the necessary income for funding furtherimprovement of Oxis’ Li-S battery technology and

achieve a cycle life that is satisfactory for otherapplications. EnSync Energy Systems (formerlyZBB Energy) has changed from a flow batterysupplier to a micro-grid solution provider. Othercompanies are focused on partnerships with utilitycompanies as a means of developingdemonstration projects and gaining visibility andcustomer confidence before developing high-volume production capacities. “Most companiesdeveloping future battery technologies are notplanning to produce batteries independently.According to them, the related risk is too high.Thus they are looking for a big company interestedin a partnership or a technology license. The big Li-ion players’ positioning regarding Li-ion technologychallengers could be affected by the arrival of newplayers from the EV/HEV industry. Indeed, novelbattery technologies are a strong focus ofautomotive OEMs such as Toyota and Tier1companies with Robert Bosch”, Rosina expects.

Market for Li-Ion technology alternatives 2015 – 2015 Source: Yole Développement 11-16


MARKET NEWS 13


Strong policies—most notably from last year’sParis Climate Agreement—facilitate investment inrenewable energy. This investment is crucial toachieving the goals of limiting the global increasein temperature to well below 2 degrees.Despite the fall in oil and gas prices,

renewables investment in 2015 reached nearlyUS$290 billion globally—almost double of whatwas spent a decade ago, according to TomiMotoi, GE (www.ge.com) representative to theInternational Energy Agency. Furthermore, newlow-carbon generation coming online in 2015exceeds the entire growth of global powerdemand in that year, according to theInternational Energy Agency’s new report,World Energy Investment 2016. This trend,driven by rapid technology progress, costdeflation and long-term price signals isexpected to continue, with the renewablesshare of total power generation anticipated tomake up 26 percent of the total global energymix by 2020. Electrification can be a solution for air

pollution and air quality and can support thedecarbonization of electricity generation,

helping the world meet its energy needs withless carbon. High rates of use andoverwhelming reliance on diesel fuel andheavy-duty vehicles account for adisproportionate share of emissions, accordingto the IEA’s Energy and Air Pollution report.Access to electric vehicles can decreaseemissions. In Paris, for example, between 2002and 2012, a mobility plan which includedshared bikes, electric vehicles and improvedvehicle efficiency decreased 30 percent of NOxemissions and 35 percent of PM10 emissionsover the period. These trends present several challenges -

and opportunities. First, the rise of variableenergy renewables deployment points to arebalancing of the energy system; as such, itrequires the effective development of newtechnologies capable of properly managingpower systems. Energy battery storage andmicrogrids can play a key role in balancingsystems with large amounts of renewablegeneration and facilitating the integration ofthese variable energy resources. Thesetechnologies also have the potential to play a

key role in countries such as Africa with limitedgrid access, helping to power these remoteregions. Technology can improve the reliability and

efficiency of electrical equipment in powerplants, two factors in determining its costcompetitiveness, which encourages its use indecarbonization and facilitates its deployment.Examples are: the latest innovation in the solarindustry uses Silicon Carbide power MOSFETsin solar inverters and can help achieve 99percent EU weighted efficiency. The efficiencygain can be translated into $2.5 million of extraenergy produced for a 100-megawatt solarplant over its lifetime. Additionally theIndustrial Internet - which looks to link energyproduction assets together via a centralplatform such as GE’s Predix - provides anumber of cost-saving and efficiency benefits.For example, a connected power plant orrenewables wind farm can be monitoredremotely, and software analytics can lead toanomalies being spotted before they occur.This can reduce downtime and can deliverelectricity where and when it’s needed.

Renewable Energies On the Rise


14 APEC 2017 www.apec-conf.org


The Latest Achievements in Power Electronics On StageAPEC (Applied Power Electronics Conference) is one of the premier global events in applied powerelectronics. APEC 2017 will be held at the Tampa Convention Center, Florida, from March 26-30, 2017.Over 5,000 delegates and 240 exhibiting companies are expected for this event. The conferenceprogram covers the latest advancements in power devices as well as their applications.

Professional Education Seminars offer a practicalmix of theory and application for the professionalworking in power electronics. APEC 2017 willfeature 18 professional education seminars on theSunday and Monday ahead of the conference thatcover a broad range of topics.Over 1200 papers have been reviewed to

ensure a balanced Technical Sessions line-up. Thetechnical program includes papers of broad appealscheduled for lecture sessions from Tuesdaymorning through Thursday afternoon. Papers witha more specialized focus are available fordiscussion with authors at the dialogue session onThursday at 11:30 a.m. Industry Sessionscontinues to excel. This track runs in parallel withthe traditional Technical Sessions Track. Speakersare invited to make a presentation only, withoutsubmitting a formal manuscript for theproceedings. This allows APEC to presentinformation on current topics in power electronicsfrom sources that would not otherwise be presentat an industry conference. While many of thesesessions are technical in nature, some also targetbusiness-oriented people such as purchasingagents, electronic system designers, regulatoryengineers, and other people who support thepower electronics industry. Rap Sessions on March 28 will include threeinteresting and controversial topics. Power Electronic Architectures: Do we needmore or have all the topologies invented?

Do we need power to progress towards ghzswitching in high-power systems andapplications?

3D Printing and power supply on-chip (PsoC) /power supply in.package (PSiP) vs. discretedesigns.

Plenary session on hot topicsOne of the outstanding sessions at APEC are thetraditional Plenaries on the Monday afternoonahead of the other sessions. These will cover inform as keynotes current topics.

Dr. Ahmad Bahai, TI, Chief Technologist and Sr. VP,Power Semiconductor Technology –Flexibility for Tomorrow’s Solutions. USBPower Delivery provides an unprecedented level

of flexibility for sophisticated power controlbetween chargers, phones, computers, monitors,accessories, and other devices. Both power anddata can flow in multiple directions and optionsexist for complex power hand-over functions likeFast-Role-Swap. A very clear and easy to followfoundation of the essential concepts andcapability is provided, stripping away theconfusion around this new standard and theassociated marketplace. Key capabilities,limitations, and technical challenges arediscussed. How today’s systems are adopting USBPower Delivery is explained and a vision of howthe market will evolve is provided. A few of themore sophisticated system concepts are alsodiscussed to provide a hint of the level ofcapability this new standard brings our industry.The talk closes with a view of what the futureholds as USB Power Delivery evolves.

Dr. Shuai Jiang and Xin Li, Google, Technical LeadManager for Power Team and Sr. DC/DC PowerArchitect for Data Centers, Google 48V PowerArchitecture. Global data center/cloud powermarket is exploding at over 10 percent annually toan estimation of 2 trillion kWh by 2020. Efficientpower delivery from utility to the point of loadcould result in an astronomical amount of energyand expenditure savings. Today’s datacenterpayloads generally use traditional 12V for sub-rackpower distributions, but the exponentiallyincreased distribution losses jeopardizes efficiencyand scalability as power grows rapidly. Google hasdeployed a compelling 48V rack ecosystem in itsdata centers for several years, which promised toprovide better efficiency, performance andscalability for more power-hungry computingsystems enabled by high-end CPUs, acceleratorsand ASICs. The 48V to point-of-load conversiontechnology is one of the key enablers. Beyond thefundamental goals of higher efficiency, higherdensity and faster response for voltage regulatordesigns, some other key metrics should also beconsidered; such as the electrical and physicalinteraction between the voltage regulator and themotherboard system, implication of integrationand power integrity, criticalness of designscalability, cost and ease of design, are some other

essential elements driving the directions oftechnology evolvement as well. In thispresentation, we will explore together with you the48V system architectures, 48V-to-PoL conversiontechnologies and challenges, and futureexploration opportunities.

Hamish Laird, CTO ELMG Digital Power, Inc. TheGap Between High Power and Low PowerConverters and How it is Closing. Large powerconverters have in the past had differentconstraints to small power converters. The first isthat large converters have a lower surface area tovolume ratio. The second is that capitalized cost ofthe lifetime power losses dominates the total costof ownership. The third constraint is that the largeconverter control is necessarily constrained by thegrid that it is connected to. Looking at thedifferences between the high power area and lowpower area there are now big leaps in efficiencythat have brought the two together in terms of theproblems that are being encountered. There arenow grid or other converter interaction issues, lowcontrol margin converters and large converterbehavior change with operating point at powerlevels as low as 500 W. In order to manage theseissues, techniques from the high power converterspace are now useful and necessary. Thepresentation will explore the gap between highpower and low power and the techniques that areuseful to fill the gap.

Conor Quinn, Artesyn Embedded Technologies &PSMA, PSMA Power Technology Roadmap Co-Chair, Empowering the Electronics Industry: APower Technology Roadmap. Every two years,the Power Sources Manufacturers Association(PSMA) publishes its Power Technology Roadmap.This release of this cycle’s roadmap coincides withAPEC 2017. The presentation will focus on newerand emerging roles for power electronics circuitsand technologies. The growth of the alternativeenergy industry, the internet as it is used today, theproliferation of mobile devices and many othertechnologies wouldn’t be possible withoutcontinued advances in power conversiontechnology. This presentation will highlight thetechnological advances in power electronics that

APEC_2017.qxp_Layout 1 09/02/2017 09:12

www.apec-conf.org APEC 2017 15


empower these applications and set the stage formore advances to come.

Dr. Ljubisa Stevanovic, GE Global Research, CTOSilicon Carbide Works, From SiC MOSFETDevices to MW-scale Power Converters. Thispresentation will provide an overview of GE’svertically integrated activities from SiC devices andmodules to converters for MW-scale industrialapplications. GE has developed a new generationof high performance SiC MOSFETs with voltageratings from 1.2 to 3.3 kV and current ratings upto 100A per die. Significant progress has beenmade towards the goal of demonstrating theMOSFET reliability comparable to mature siliconIGBTs. Extensive stress testing has also mappedout the device’s safe operating area, includingavalanche capability, short circuit ruggedness, body

diode surge and stability, and terrestrial cosmicradiation hardness. In addition, a portfolio of lowinductance half-bridge modules has beendeveloped and optimized for fast switching SiCMOSFETs. By taking advantage of the MOSFET’sbody diode, the modules do not require anti-parallel diodes, saving cost and floor-space foradditional MOSFETs. When compared to Siliconmodules with the same mechanical footprint andvoltage ratings (e.g. 1.7kV), the SiC modulesdeliver twice as much current (500 Arms), evenwhen operating at three times higher switchingfrequency (7.5 kHz). Such performance advantageis also due in part to robust gate drivers with fastcontrol and protection features. These efforts haveculminated with the launch of the World’s firstMW-scale all-SiC product at the Solar PowerInternational tradeshow in September 2016. The

2.5 MW utility scale SiC PVInverter offers the best in class99.0% EU weighted efficiency,delivering between 1 and 2 %more energy to customers. Thesingle -stage inverter features asimple two-level topologyswitching at 8 kHz and offershigher reliability due to reducedparts count.

Vatché Vorperian, Jet PropulsionLaboratory, Principal Engineer &Fellow of the IEEE, A HistoricalPerspective on theDevelopment of the PWMSwitch Model. In thispresentation, he will talk aboutthe earliest instances in thepublished literature that includethe works of Cuk, Landsman,Meares and Tymersky amongothers, of the appearance of asub-circuit of a dc-to-dcconverter as a building block ofdc-to-dc converters and itsconnection to the conversionratio of that converter. He willthen present the subsequentemergence of the PWM switchas the smallest sub-circuit of a

converter with invariant structural and electricalcharacteristics which bestow it with an invariantequivalent circuit model. To render the model ofthe PWM switch easily accessible to all thosestudying power electronics, from the beginning itwas promoted by pointing out its similarity to themodel of the transistor and its utilization inamplifier circuit analysis since both, the PWMswitch and the transistor, are three-terminal non-linear devices. From a pedagogical point of view,the idea has caught on well and today the modelof the PWM switch is being taught at Universitiesand to industry. Some examples of the applicationof the PWM switch model to the analysis ofmodern converters such the coupled SEPIC andCuk converters will be presented.

More in our next issue. AS


Power Electronics Europe

subscribe today at:

www.power-mag.com

APEC_2017.qxp_Layout 1 09/02/2017 09:13

16 INDUSTRY NEWS


Power Integration’s new LinkSwitch-TN2 ICs are specifically designed toreplace all linear and capacitor-fed (cap dropper) non-isolated powersupplies in the under 360 mA output current range at equal system costwhile offering much higher performance and energy efficiency.Applications include appliances, HVAC, industrial, home automation (IoT)and metering systems, particularly those destined for India and othergeographies with challenging power grid stability.Unlike conventional PWM (pulse width modulator) controllers,

LinkSwitch-TN2 uses a simple ON/OFF control to regulate the outputvoltage. It consists of an oscillator, feedback (sense and logic) circuit, 5.0V regulator, BYPASS pin under-voltage circuit, over-temperatureprotection, line and output over-voltage protection, frequency jittering,current limit circuit, leading edge blanking and a 725 V power MOSFET.Additional circuitry for auto-restart is incorporated. The device familysupports buck, buck-boost and flyback converter topologies. It featurevoltage regulation of better than -/+ 3%. This high level of accuracyallows designers to eliminate post regulators, minimizing the BOM,increasing efficiency and reducing size. The new IC requires just 20additional components to complete a buck converter, and may beconfigured to use off-the-shelf inductors, further reducing cost and supplychain complexity.

High efficiency for low power applicationsThe new devices are very efficient in low-power applications– above 80 % in 12 V, 120 mA (1.4 W) buck designs for example. Designstypically consume less than 30 mW no-load in a buck arrangement andless than 10 mW when configured as a non-isolated flyback. This is a keytool for designers addressing Total Energy Consumption (TEC)regulations, which prescribe an energy budget limit over a range ofoperating modes. TN2 ICs consume very little current in standby resulting in power

supply designs that meet all no-load and standby specificationsworldwide. MOSFET current limit modes can be selected through theBYPASS pin capacitor value. This pin has multiple functions: It is the connection point for an

Highly Efficient Low Power ON/OFF Switcher

external bypass capacitor for the internally generated 5.0 V supply. It is amode selector for the current limit value, depending on the value of thecapacitance added. Use of a 0.1 �F capacitor results in the standardcurrent limit value. Use of a 1 �F capacitor results in the current limitbeing reduced, allowing design with lowest cost surface mount buckchokes. It also provides a shutdown function. When the current into theBYPASS pin exceeds IBPSD for a time equal to 2 to 3 cycles of theinternal oscilator (fOSC), the device enters auto-restart. This can be used toprovide an output over-voltage protection function with external circuitry.The high current limit level provides maximum continuous output

current while the low level permits using very low cost and small surfacemount inductors. A suite of protection features enable safe and reliablepower supplies protecting the device and the system against input andoutput over-voltage faults, device over-temperature faults, lost regulation,and power supply output overload or short-circuit faults. The devicefamily is available in PDIP-8C, SO-8C, and SMD-8C packages.

Functional descriptionThe typical oscillator frequency is internally set to an average of 66 kHz.Two signals are generated from the oscillator: the maximum duty cyclesignal (DC(MAX)) and the clock signal that indicates the beginning of eachcycle. The oscillator incorporates circuitry that introduces a small amountof frequency jitter, typically 4 kHz peak-to-peak, to minimize EMIemission. The modulation rate of the frequency jitter is set to 1 kHz tooptimize EMI reduction for both average and quasi-peak emissions. The feedback input circuit at the FEEDBACK pin consists of a low

impedance source follower output set at VFB (2.0 V). When the currentdelivered into this pin exceeds IFB (49 �A), a low logic level (disable) isgenerated at the output of the feedback circuit. This output is sampled atthe beginning of each cycle on the rising edge of the clock signal. If high,the power MOSFET is turned on for that cycle (enabled), otherwise thepower MOSFET remains off (disabled). The sampling is done only at thebeginning of each cycle. Subsequent changes in the FEEDBACK pinvoltage or current during the remainder of the cycle do not impact theMOSFET enable/disable status. If a current greater than IFBSD is injectedinto the feedback pin while the MOSFET is enabled for at least twoconsecutive cycles the part will stop switching and enter auto-restart off-time. Normal switching resumes after the auto-restart off-time expires.This shutdown function allows implementing line over-voltage protectionin flyback converters. The current into the FEEDBACK pin should belimited to less than 1.2 mA.The 5.0 V regulator charges the bypass capacitor connected to the

BYPASS pin to VBP by drawing a current from the voltage on the DRAIN,whenever the MOSFET is off. The BYPASS pin is the internal supplyvoltage node for the LinkSwitch-TN2. When the MOSFET is on, the deviceruns off of the energy stored in the bypass capacitor. Extremely lowpower consumption of the internal circuitry allows the LinkSwitch-TN2 tooperate continuously from the current drawn from the DRAIN pin. Abypass capacitor value of 0.1 �F is sufficient for both high frequencydecoupling and energy storage.The current limit circuit senses the current in the power MOSFET. When

this current exceeds the internal threshold (I LIMIT), the power MOSFET isturned off for the remainder of that cycle. The leading edge blankingcircuit inhibits the current limit comparator for a short time (tLEB ) after thepower MOSFET is turned on. This leading edge blanking time has beenset so that current spikes caused by capacitance and rectifier reverserecovery time will not cause premature termination of the switchingpulse. Current limit can be selected using the BYPASS pin capacitor

LinkSwitch-TN2 ICs are specifically designed to replace all linear and capacitor-fed (capdropper) non-isolated power supplies

Industry News.qxp_Layout 1 09/02/2017 09:40

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18 INDUSTRY NEWS


(0.1 �F for normal current limit / 1 �F for reduced current limit).LinkSwitch-TN2 selects between normal and reduced current limit atpower-up prior to switching.The output over-voltage protection uses auto-restart that is triggered by

a current >IBPSD into the BYPASS pin. In addition to an internal filter, theBYPASS pin capacitor forms an external filter providing noise immunityfrom inadvertent triggering. For the bypass capacitor to be effective as ahigh frequency filter, the capacitor should be located as close as possibleto the SOURCE and BYPASS pins of the device.

Dual output adapter applicationA 4.75 W dual output adapter using LNK3206D is an example for thesimplicity of a power supply design. Input rectification is provided by diode D1. The rectified input is filtered

by capacitors C1 and C2. The π (pi) filter comprising of inductor L1 andcapacitors C1 and C2 provides filtering for differential mode EMI. EMI isfurther reduced by the integrated frequency jitter feature of the devicesas described above. Fusible resistor RF1 provides additional differentialfiltering and also protects by safely opening the circuit in case ofcatastrophic failure of any of the components in the circuit.An internal current source from the DRAIN (D) pin of the LNK3206D

IC U1, charges the capacitor C3 to provide control supply to thecontroller inside the IC. During the power MOSFET off-time, capacitor C5is charged to the output voltage via D4. This voltage is used to providefeedback to the IC via the resistor divider formed by resistors R1 and R2.The FEEDBACK (FB) pin is sampled by the controller inside U1 duringeach switching cycle. If current flowing into the FB pin is below 49 �Awhen the sampling occurs, controller switching is enabled for thatparticular switching cycle and the power MOSFET turns on. This willdevelop a linear ramp in current through inductor T1 and C8. Once theinternal current limit is reached, the power MOSFET inside IC U1 isturned OFF and will remain OFF for the remaining portion of theswitching cycle and the inductor current can freewheel via diode D2.The regulation of the main output is maintained by skipping cycles(ON/OFF control).During full load operation, only a few switching cycles will be skipped

(disabled), which results in a high effective switching frequency. As theload is reduced, more switching cycles are skipped which reduces theeffective switching frequency. At no-load, most switching cycles areskipped and that makes the no-load power consumption of supplies low.Switching losses are the dominant loss mechanism at light loading andeffective drop in switching frequency helps to improve light loadefficiency. Additionally, since the amount of energy per switching cycle isfixed by ILIMIT, the skipping of switching cycles gives the supply a nearly flatefficiency characteristic over the load range.LinkSwitch-TN2 family of devices do not require an external bias supply

for operation and can be configured to be self-powered, however,

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LinkSwitch-TN2 functional block diagram


INDUSTRY NEWS 19


providing the operating current for the device into the BYPASS (BP) pinexternally, dramatically reduces no load input power. Resistor R4connected from output sampling capacitor C5 to the BP pin provides therequired supply current for the IC U1. To achieve lowest no-load powerconsumption, the current fed into the BP pin should be slightly higherthan 120 �A. For the best full load efficiency and thermal performance,the current fed into the BP pin should be slightly higher than 290 �Ahowever that will marginally increase the no-load input power. CapacitorC9 ensures stable operation.

Additional auxiliary 5 V output is obtained using an additional windingon the inductor T1. This winding is rectified and filtered by diode D3 andcapacitor C6. Diode D3 is a Schottky diode to reduce rectification loss.Generally a 5 V or 3.3 V supply required for operating digital circuits in

practical applications, requires regulation <5 %. A low cost linearregulator IC U2 provides a regulated 5 V output. Capacitor C7 providesfiltering for IC U2.

www.power.com/linkswitch-tn2

4.75 W dual output adapter designusing LNK3206D

Power Integrations introduced in January 2017 an extension to itsLinkSwitch-TN2, the LinkSwitch-XT2 family. LinkSwitch-XT2 ICstarget isolated and non-isolated flyback applications in whichaccurate regulation of output voltage and current are important.The new ICs can deliver up to 6.1 watts in wide-input rangedesigns, and up to 9.2 watts for 230 VAC open-frameapplications.Designed for flyback topologies, the XT2 family delivers current

and voltage regulation of better than -/+ 3% and typical efficiencyabove 80 % while consuming less than 10 mW in no-loadconditions. High (132 kHz) operating frequency enables the use of

small power transformers, while the programmable current limitfunction enables further transformer optimization. XT2 ICscombine also a 725 V power MOSFET with control circuitry on asingle Silicon die. Integrated safety and reliability features includeinput over-voltage protection, hysteretic thermal shutdown forover-temperature protection, and auto-restart for output short-circuit, over-voltage and open-loop protection. The ICs come inthree packages: P-package (DIP-8C), D-package (SO-8C), and G-package (SMD-8C).

www.power.com/products/linkswitch-xt2/

Switcher Family Extended


20 INDUSTRY NEWS


Intersil recently introduced digital multiphase controllers and a companionsmart power stage, including the Adaptive Voltage Scaling Bus (AVSBus). Thenew digital controllers provide up to seven phases assignable in anycombination across two outputs, and combine with smart power stages toprovide a scalable solution from 10 A to 450 A. AVSBus™ joins the PMBus™ v1.3 specification and features a 50 MHz high-

speed bus that connects directly to the processor to communicate telemetrydata and deliver efficiency savings through adaptive voltage positioning.Intersil’s new DC/DC controllers and ISL99227 60A smart power stagesupport demanding CPU core voltages, memory, and auxiliary power rails,enabling power designers to customize their solution to meet any railrequirements.The digital multiphase family is comprised of three groups of controllers.

The ISL68137 and ISL68134 controllers utilize the AVSBus to power andcommunicate with ARM-based processors in network routers, switches,servers, storage, and wireless telecom equipment. Two general-purposecontrollers (ISL68127 and ISL68124) power network processors, FPGAs, SoCsand graphics accelerators. And eight controllers (ISL69147/44, ISL69137/34,ISL69128/27 and ISL69125/24) add a secondary high-speed interface (SVIDor SVI2) to power the latest Intel and AMD processors in cloud computingapplications that make up the Internet of Things (IoT) backbone.The ISL681xx and ISL691xx controllers integrate a digital engine featuring a

patented synthetic current control architecture that tracks each phase currentwith zero latency. This allows the device to respond to any load transient withprecise current and voltage positioning. Synthetic current control also makes itpossible to develop high reliability systems using all-ceramic capacitors.Switching frequency is user configurable over a range of 200 kHz to 1 MHz.

PWM modulation schemeThe ISL68134 i. e. uses a proprietary linear synthetic current modulationscheme to improve transient performance. This is a constant frequency, dualedge PWM modulation scheme with both PWM leading and trailing edgesbeing independently moved to give the best response to transient loads.Current balance is an inherent part of the regulation scheme. The modulationscheme is capable of overlapping pulses should the load profile demand suchoperation. In addition, the modulator is capable of adding or removing pulsesfrom a given cycle in response to regulation demands while still managingmaximum average frequency to safe levels. For DC load conditions theoperating frequency is constant.In order to produce the most optimal efficiency across a wide range of

output loading, the modulator supports automatic dropping or adding ofphases. Use of automatic phase dropping is optional. If automatic phasedropping is enabled, the number of active phases at any time is determinedsolely by load current. During operation, phases of Output 1 will dropbeginning with the lowest phase number assigned. Phase dropping beginswith the highest assigned phase number. Phases are dropped one at a time with a user programmed drop delay

between drop events. As an example, suppose the delay is set to 1 ms and 3phases are active. Should the load suddenly drop to a level needing only 1phase, the ISL68134 will begin by dropping a phase after 1 ms. An additionalphase will be dropped each 1 ms thereafter until only 1 phase remains. Inaddition to the described load current add/drop thresholds, the fast phase addfunction provides a very rapid response to transient load conditions. Thisfeature continuously monitors the system regulation error and should itexceed the user set threshold, all dropped phases will be readied for use. In

Multiphase PWM Controllers withAVSBus and Synthetic Current Control

ISL 68/69xxx multiphase contollers andISL99227 SPS forming a complete digital

power solution

ISL68134 internal block diagram


INDUSTRY NEWS 21


KEEP UP WITHTHE TIMES

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Typical characteristic of efficiency vs load current vs phase count

this way, there is no delay should all phases be needed to support a loadtransient. The fast phase add threshold is set in the PowerNavigator GUI.Output current threshold for adding and dropping phases can also beconfigured.

To ensure dropped phases have sufficient boot capacitor charge to turn onthe high-side MOSFET after a long period of disable, a boot refresh circuitturns on the low-side MOSFET of each dropped phase to refresh the bootcapacitor. Frequency of the boot refresh is also programmable viaPowerNavigator.

The ISL68134 supports up to two regulated outputs through fourconfigurable phases. Either output is capable of controlling up to four phasesin any arbitrary mix. Phase assignments are accomplished via thePowerNavigator GUI. While the device supports arbitrary phase assignment, itis good practice to assign phases to Output 1 in descending sequentialnumerical order starting from Phase 3. For example, a 3-phase rail couldconsist of Phases 3, 2 and 1. For Output 0, phases would be assigned startingfrom Phase 0 in ascending sequential numerical order.

Output voltage configurationOutput voltage set points and thresholds for each output can be configuredwith the GUI. Parameters such as output voltage, VOUT margin high/low andVOUT OV/UV faults thresholds can be configured with GUI. Additionally, outputvoltage and margin high/low can be adjusted during regulation via PMBuscommand VOUT_COMMAND, VOUT_MARGIN_HIGH andVOUT_MARGIN_LOW for further tuning.

Smart power stage fault detectThe ISL99227, ISL99227B are Smart Power Stages (SPS) compatible withISL68xxx/69xxx Digital Multiphase (DMP) controllers and phase doubler(ISL6617A), respectively.

The ISL99227, ISL99227B have integrated current and temperature

ISL99227 simplified application block diagram


A complete typical digital power solution - ISL68xxx withISL99227 SPS

22 INDUSTRY NEWS

monitors that can be fed back to the controller and doubler to complete amultiphase DC/DC system. They simplify design and increase performanceby eliminating the DCR sensing network and associated thermalcompensation. Light-load efficiency is supported via a dedicated LFET controlpin. The ISL99227, ISL99227B feature a 3.3 V compatible, 5.0 V compatible tri-

state PWM input that provide a robust solution in the event of abnormaloperating conditions. The ISL99227, ISL99227B also improve systemperformance and reliability with integrated fault protection of UVLO, over-temperature and over-current. An open-drain fault reporting pin simplifies thehandshake between SPS and controllers and can be used to disable the

controller during start-up and fault conditions.SPS will output a large signal if peak current exceeds

their preprogrammed threshold. The ISL68134 isequipped to detect this fault flag and immediately shutdown. This detector is enabled on the GUIOverCurrent Fault setup screen. This feature functionsby detecting signals which exceed the current senseADC full scale range. If this detector is disabled whileusing a SPS, the Fault# signal must be connected tothe controller Enable pin of the associated rail. This willensure that an SPS OC event will be detected and theconverter will shutdown.

AVSBus functionalityThe AVSBus interface provides a high speed (up to 50MHz) serial interface to the ISL68134 allowing

implementation of advanced voltage scaling functions supporting increasedsystem efficiency and performance. Devices equipped with AVSBus mastercapability may use the interface to enable rapid supply voltage changes tosupport low power consumption modes as well as high performance modes.Due to the advanced digital regulation loop employed, the ISL68134 is wellequipped to support very rapid transition rates. All commands are readable atall times, but they cannot be written to unless the device is set to AVSBuscontrol.

www.intersil.com/en/products/power-management/zilker-labs-digital-power/digital-multiphase-controllers.html

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PCIM Europe 2016 featured a total of 436 exhibitors, as well as 93represented companies, more than 10,000 visitors, and 771 conferencedelegates. For 2017 all signs are pointing to success - exhibitor registrationsincreased by around ten percent and the exhibition area has remarkably grownby 12 percent. From 16 – 18 May 2017, the conference and internationalexhibitors will deliver customized know-how, introduce their innovations andprovide insights into the latest trends and developments in power electronics.For the first time in 2017, companies get the opportunity to present

themselves and their expertise at joint stands. At the E-Mobility Area it allrevolves around electric mobility. It is aimed at companies specialized in powerelectronics in E-Mobility such as batteries, battery management, or drive trainsolutions. It therefore offers the possibility to introduce products, solutions andservices to an interested audience in one single spot. Thanks to the highinternationality of PCIM Europe, the event is now included in the BMWi-program. This program is designed to promote the exhibition participation of

young innovative German companies on a thematic pavilion. This promotionarea offers companies the unique chance to present themselves to aninternational expert’s community, as well as promising business potentials inthe environment of power electronics.The application-oriented PCIM Europe conference will take place in parallel

to the exhibition. The conference program covers issues ranging from recentdevelopments in power semiconductors, passive components, thermalmanagement products, energy storage, and sensors to new materials andsystems.Already on the Sunday (May 14) seven seminars will be held on the subjects Basics of Electromagnetic Compatibility (EMC) of Power Systems Multi-Kilowatt Flyback Converters; Advantages and Practical DesignConsiderations

What a Design Engineer Should Know About Current-Mode Control Modern Magnetic Technologies for High Efficiency and High Power Density

www.pcim-europe.com PCIM 2017 23


Greatest European Power Electronics Event

Again it’s time forPCIM Europe inMay 2017

PCIM.qxp_Layout 1 09/02/2017 09:10

24 PCIM 2017 www.pcim-europe.com


Power Electronics and Control for Battery Systems Power Supply Design Review: Achieving 98% Efficient Power Supplies UsingGaN FETs

Design of Magnetic Components for High Power Converters followed byseminars on the Monday (May 15) covering the following topics

New Trends in Power Conversion for Very High Efficiency and High PowerDensity

What a Design Engineer Should Know About Power Factor Correction Electromagnetic Design of High Frequency Converters and Drives High Performance Control of Power Converters Advanced System Design with Ultra-Fast Si/SiC/GaN Power SemiconductorDevices

Design Considerations for High Frequency Linear Magnetics Reliability of Si and SiC Power Devices and Packages Driving Electric - Power Train, Battery, Wireless Charging and AutonomousDriving

Design Challenges for High Frequency Magnetic Circuit Design for PowerConversion

Reliability Engineering in Power Electronic Systems Energy Storage - Systems and Components

The conference starts on the Tuesday (May 16) with the Opening, YoungEngineer Award and Best Paper Award Ceremony. First oral sessions will coverHV-SiC-MOSFET featuring 3.3 kV/450 A Full-SiC nHPD2 (next High PowerDensity Dual) with Smooth Switching by Hitachi Power Semiconductor Device,Characterization of 3.3kV and 6.5kV SiC MOSFET by ROHM Semiconductor,Dynamic Characterization of Next Generation Medium Voltage (3.3 kV, 10 kV)Silicon Carbide Power Modules by Wolfspeed, and 3.3kV All-SiC PowerModule for Traction Application by Mitsubishi Electric.In the afternoon the session SiC MOSFET covers the papers Short-Circuit

Robustness of Discrete Silicon Carbide MOSFETs in Half-Bridge Configuration

by Mitsubishi Electric, The new CoolSiC Trench MOSFET Technology for LowGate Oxide Stress and High Performance by Infineon Technologies, DeviceSimulation Modeling of 1200 V SiC MOSFETs by Fairchild Semiconductor, andDesign Rules To Adapt The Desaturation Detection For SiC MOSFET Modulesby the University of Bayreuth.Another oral session SiC-Systems on the Wednesday afternoon cover

papers A Novel Gate Drive Concept to Eliminate Parasitic Turn-on of SiCMOSFET in Low Inductance Power Modules by the University of Bayreuth,Evaluation of Current Measurement Accuracy for a Power Module withIntegrated Shunt Resistors by Semikron Elektronik. And on the Thursdayafternoon the oral session SiC Modules Diodes will present subjects such asDesign and Analysis of a Low-Inductive Power-Semiconductor Module with SiCT-MOSFET and Si IGBT in Parallel Operation by Infineon Technologies, 1.7 kVHigh-Current SiC Power Module Based on Multi- Level Substrate Concept andExploiting MOSFET Body Diode during Operation by ABB Corporate Research,All SiC Module with 1st Generation Trench Gate SiC MOSFETs and NewConcept Package by Fuji Electric Europe, and Robust SiC JBS Diodes for theApplication in Hybrid Modules by ABB Switzerland Ltd.Gallium Nitride device technology will be covered in one oral session called

Advanced Wide Bandgap – GaN on the Thursday (May 18) morning only.Papers to be presented are Investigation of GaN-HEMTs in ReverseConduction by Fraunhofer Institute for Applied Solid State Physics (IAF), Short-Circuit Robustness for 650 V E-Mode GaN Transistors, Current Measurementfor High Speed Protection Circuit by ENS Cachan, Mechatronic Design of 2 kWSiC DC/AC Converter with 200 W/inch by Fraunhofer Institut für IntegrierteSysteme und Bauelementetechnologie IISB, A Full SiC Module Operational at200°C Junction Realized by a New Fatigue-Free Structure by National Instituteof Advanced Industrial Science and Technology of Japan, and A Novel SiCPower Module with 3D Integration by ON Semiconductor.

More in our next issue. AS

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25_pee_0117.indd 1 09/02/2017 10:06

26 DIGITAL POWER www.ericsson.com


Benefits of Direct 48 V / 1 VConversionIn data centres and telecom offices, the most important issues affecting decisions about power supply designare usually cost, efficiency, and the available board real estate. Typical early power distribution strategiesutilized multiple isolated quarter brick or eighth brick converters to convert from a bus voltage – usually 48 V– to the required IC supply voltage, at the point of load. A new generation of single-stage converters is set toemerge, to convert down from 48 V directly to logic voltages at high efficiency and within compactdimensions. Bob Cantrell, Senior Application Engineer, Ericsson Power Modules, USA

In a bid to save the cost and bulk ofmultiple isolated converters, the now-conventional distributed power architecturewas proposed and became widelyadopted in data centers (Figure 1) over adecade ago. This comprises an AC/DCfront-end power supply, an isolatedIntermediate Bus Converter (IBC) usuallyof an industry-standard size such as aquarter brick, and on-board non-isolatedPoint-of-Load (POL) converters. The POLsare positioned close to the power pins ofdevices such as processors, FPGAs/ASICs,memory, and other ICs, to minimize noiseeffects and optimize transient response. The IBC down-converts the nominal 48

V DC from the front-end power supply to a12 V rail that is distributed to the POLconverters. The POLs then convert the 12V input into regulated voltages as neededby on-board ICs. These typically can rangeto below 1 V as needed to powerprocessor or FPGA core logic.

Efficiency is keyToday, data centres and telecom offices areunder pressure to support ever-increasingnumbers of subscribers and connections,and to deliver increasingly data-intensiveservices with minimal latency. Accordingly,the peak power consumption of largeserver boards has risen significantly above

1 kW and is likely to push well beyond 3kW in the future. As power consumptioncontinues to rise, efficiency is a growingconcern for data centres seeking to controlthe spiralling costs of powering servers andcooling systems, and minimize the overallenterprise environmental footprint. Thecost of power consumed in a large-scaledata center quickly outweighs the cost ofservers and networking equipment, andenergy prices can be expected to continuerising.

Advantages of direct conversion Although many of today’s IBC and POLconverters can achieve efficiency in the

Figure 1: Typical data cabinet utilizing conventional point-of-load power architecture

Ericsson_feature.qxp_Layout 1 08/02/2017 16:19

www.ericsson.com DIGITAL POWER 27


region of 95-96 % for the IBC, and 90 %for a typical 12 V-1 V POL at a particularload, the cumulative energy loss from bothstages of conversion can reduce overallefficiency to a little over 86 % (Figure 2a).If a single converter can generate therequired IC supply voltage with efficiency,say 89 % for the same load used in theabove example, the overall conversionefficiency can be increased by severalpercentage points (Figure 2b). The I2R distribution losses can also be

reduced. By distributing 48 V DC for directconversion at the point of load, the bussupplying the converter carriesapproximately 25 % of the current thatwould be required to deliver the samepower at 12 V. Hence I2R distributionlosses from the 48 V source can bereduced by a factor of 16. Reducing I2Rdistribution losses becomes increasinglyimportant as total server power – andhence the power delivered to the POLs at12 V or 48 V – continues to increase. In addition, direct conversion helps to

save board real-estate and to reduce thecost of materials, electronics assembly andmanufacturing. Using today’s technology, adirect 48 V-to-POL converter solution canbe smaller in size than comparableconventional modules in quarter or eighth-brick sizes along with POL converters, andcan also eliminate the need for high-current multiple and parallel IBC quarterbricks or eighth bricks. In complex or high-power systems, the need for a reduced-power Intermediate bus will still likely existto power low-current rails, but an eighth

brick IBC converter will likely be able to beused, thereby saving additional boardspace.

High-efficiency direct conversionA new generation of single-stageconverters is set to emerge, to convertdown from 48 V directly to logic voltagesat high efficiency and within compactdimensions. The converters will be capableof supporting the low duty cycles requiredto convert from, say, 48 V to 1.0 V, whileoperating at a high switching frequency toensure fast transient response andminimize reliance on decouplingcapacitance and magnetic components.The adoption of direct conversion,implemented using the latest powertechnologies, is an emerging trend. Theindustry needs to identify the sweet spotas far as specifics such as module currentratings or power delivery are concerned.The new direct conversion solutions will

enter the market alongside existing IBCand POL products that are currently usedto power boards from a few hundredWatts up to 3 kW or more. Directconversion is expected to deliver thegreatest efficiency gains in equipment athigher power levels, and can be used todramatically reduce loads in IntermediateBus Converters thereby allowing smallerIBCs; possibly downsizing these fromquarter brick to smaller eighth brick units.This should be ideal for next-generationhigh-current processors. On the other hand, factors such as cost or

legacy issues may determine the point at

which some equipment manufacturersconsider implementing direct conversion.With direct-conversion and traditionalmodules available side-by-side in the market,designers will also have the freedom toconceive hybrid architectures that combineIntermediate Bus and Direct Conversiontopologies to deliver the best of both worlds.

ConclusionUsing a higher voltage such as 48 V todistribute power on server boards, andconverting directly to the required loadvoltage at the point of load, offers attractiveadvantages including higher efficiency,lower I?R distribution losses, as well asreducing board space imposed by anintermediate converter. In practice, costpressure, combined with engineeringconstraints on switching frequency, step-down ratio and transient performance,have historically driven power designerschallenged to convert from a 48 V DCinput to use a two-stage topologycomprising an intermediate converterfeeding point-of-load converters thatgenerate the desired IC supply voltages.Now, with the growing imperative tomaximize energy efficiency in every area ofthe server design, and drawing on thelatest power technologies, directconversion can provide not only the mostefficient power-conversion architecture, butalso board-space savings and potentialcost advantages. The forthcominggeneration of direct-conversion POLmodules will establish the starting point fora major transition in the market.

Figure 2a: Conventional two-stage 48 V-to-core voltage conversion

Figure 2b: Direct 48 V-to-core voltage conversion

Ericsson_feature.qxp_Layout 1 08/02/2017 16:19

28 AUTOMOTIVE POWER www.linear.com


Dual Battery Require Bi-Directional DC/DC ControllersWith fuel economy regulations tightening and autonomous-driving capability with connectivity proliferating,the old-fashioned 12 V automotive electrical system has reached its usable power limit. Furthermore, a vastincrease in automotive electronic systems, coupled with related demands on power, has created an array ofnew engineering opportunities and challenges. As a result, the 12 V lead-acid battery automotive systemwith its 3 kW power limit has been supplemented. A newly proposed automotive standard, LV148,combines a secondary 48 V bus with the existing 12 V system. Bruce Haug, Senior Product MarketingEngineer, Linear Technology, Milpitas, USA

The 48 V rail includes an integratedstarter generator (ISG) or belt startgenerator, a 48 V lithium-ion battery and abi-directional DC/DC converter for deliveryof up to 10 kW of available energy fromthe 48 V and 12 V batteries combined. Thistechnology is targeted at conventionalinternal combustion automobiles, as well ashybrid electric and mild hybrid vehicles, asauto manufacturers strive to meetincreasingly stringent carbon dioxideemissions targets.

More power required Typically, the 12 V bus will continue topower the ignition, lighting, infotainmentand audio systems. The 48 V bus willsupply active chassis systems, airconditioning compressors, adjustablesuspensions, electric superchargers/turbosand also support regenerative braking. Thedecision to use an additional 48 V bus,which is expected be available acrossproduction model ranges soon, can alsosupport starting the engine, which wouldmake stop-start operation smoother.Moreover, the higher voltage meanssmaller cable cross-sections are neededwhich reduces cable size and weight.Today’s high-end vehicles can have morethan 4 kilometers of wiring. Vehicles willbecome more like PCs, creating thepotential for a host of plug-and-playdevices. On average, commuters spend 9% of their day in an automobile. Thus,introducing multimedia and telematics intovehicles can potentially increaseproductivity as well as providing additionalentertainment.The key components for autonomous

driving include a computer, cameras, radarand LiDAR sensors, all of which requireadditional energy. This additional energy isrequired to improve vehicles’ connectivity,not just to the Internet, but to othervehicles and buildings, traffic signals and

other structures in the environment.Furthermore, drivetrain components, powersteering, oil and water pumps will switchover from mechanical to electrical power.The future for the 48 V battery system is

much more near-term than the fullyautonomous car, although manyautomotive suppliers see strong demandfor the technological building blocksultimately needed for self-driving vehiclesover the next few years. According to someauto manufactures, a 48 V based electricalsystem results in a 10-15 % gain in fueleconomy for internal combustion enginevehicles, thereby reducing CO2 emissions.Moreover, future vehicles that use a dual48 V/12 V system will allow engineers tointegrate electrical booster technology thatoperates independently of the engine load,thereby helping to improve accelerationperformance. Already in its advanceddevelopment phase, the compressor isplaced between the induction system andintercooler and uses 48 V to spin-up theturbos. Nevertheless, the implementation of an

additional 48 V supply network intovehicles translates into major designchallenges for suppliers across the valuechain. In particular, providers ofsemiconductors and Electronic ControlUnits (ECUs) will be affected – they willneed to adjust their operational range tothe higher voltage and in part re-designtheir products. Correspondingly, themanufactures of DC/DC converters willneed to develop and introduce specializedICs to enable this high power transfer. It is clear that there is a need for a bi-

directional step-down and step-up DC/DCconverter that goes between the 12 V and48 V batteries. This DC/DC converter canbe used to charge either battery and allowsboth batteries to supply current to thesame load if required. Most of the early 48V/12 V dual battery DC/DC converter

designs use different power components tostep-up and step-down the voltage.However, the recently released LTC3871 bi-directional DC/DC controller from LinearTechnology uses the same external powercomponents for the step-up conversion asit does for stepping down the voltage.

A single bi-directional IC solutionThe LTC3871 is a 100V/30V bi-directionaltwo phase synchronous buck or boostcontroller which provides bi-directionalDC/DC control and battery chargingbetween the 12 V and 48 V board nets. Itoperates in buck mode from the 48 V busto the 12 V bus or in boost mode from 12V to 48 V. Either mode is configured ondemand via an applied control signal. Up to12 phases can be paralleled and clockedout-of-phase to minimize input and outputfiltering requirements for high currentapplications (up to 250 A). Its current-mode architecture provides currentmatching between phases when paralleled.Up to 5 kW can be supplied in buck modeor in boost mode with a 12-phase design. When starting the car, or when additional

power is required, the device allows bothbatteries to supply energy simultaneouslyby converting energy from one board netto the other. Up to 97 % efficiency can beachieved and the on-chip currentprogramming loop regulates the maximumcurrent that can be delivered to the load ineither direction. Four control loops, two forcurrent and two for voltage, enable controlof voltage and current on either the 48 V or12 V board nets.The LTC3871 operates at a user

selectable fixed frequency between 60 kHzand 475 kHz, and can be synchronized toan external clock over the same range. Theuser can select from continuous operationor pulse skipping during light loads.Additional features include overload andshort-circuit protection, independent loop

Linear_COVER FEATURE.qxp_Layout 1 08/02/2017 16:22

www.linear.com AUTOMOTIVE POWER 29


compensation for buck and boost modes,EXTVcc for increased efficiency, ±1%output voltage regulation accuracy overtemperature, along with under-voltage andover-voltage lockout. The LTC3871 hasbeen qualified to meet AEC-Q100specifications and was designed fordiagnostic coverage in ISO26262 systems.The LTC3871 is available in a thermally

enhanced 48-lead LQFP package. Threetemperature grades are available, withoperation from –40°C to 125°C for theextended and industrial grades and a hightemp automotive range of –40°C to 150°C.Figure 1 shows its typical applicationsschematic. The P-Channel MOSFET shownat the top of the schematic is for over-current and short-circuit protection.

Integrated starter-generator operation modesThe electronically controlled ISG replacesboth the conventional starter and alternatorwith a single electric device for thefollowing reasons: 1 - eliminate the starterwhich is only a passive component duringengine operation; 2 - replaces the presentbelt and pulley coupling between thealternator and the crankshaft; 3 - providefast control of the generator voltage duringload dumps; and 4 - eliminate the slip ringsand the brushes in some present woundrotor alternators.The ISG has three important features

which are the start-stop function, electricitygeneration and power assistance. The ISGallows the internal combustion engine to

turn off its motor to save fuel at stops andinstantly re-starts upon pressing of the gaspedal. Normally referred to as a start-stopsystem, an ISG makes for a smoother

transition when starting the engine. Like aconventional alternator, the ISG produceselectric power when the vehicle is running.In addition, the ISG can help to decelerate

Figure 1: LTC3871 bi-directional schematic 12 V output from a 26 V to 58 V input delivering 30 A of current

Figure 2: Block diagram of the ISG, LTC3871 along with the 12 V and 48 V batteries are incorporated


30 AUTOMOTIVE POWER www.linear.com


the vehicle by generating electric power(regenerative braking). The electric powergenerated during regenerative brakingcharges the 48 V battery, which in turnreduces fuel consumption and its resultantemissions. Figure 2 shows a block diagramhow the ISG, LTC3871 along with the 12volt and 48 volt batteries are incorporatedinto an internal combustion engine vehicle.The LTC3871 can be dynamically and

seamlessly switched from buck mode toboost mode and vice versa via a simplecontrol signal. There are two separate erroramplifiers for VHIGH or VLOW regulation. Havingtwo error amplifiers allows fine tuning ofthe loop compensation for the buck andboost modes independently to optimizetransient response. When the buck mode isselected, the corresponding error amplifieris enabled, and ITHLOW voltage controls thepeak inductor current. The other erroramplifier being disabled. In boost mode,ITHHIGH is enabled while ITHLOW isdisabled. During a buck to boost or a boostto buck transition, the internal soft-start isreset. Resetting soft-start and parking theITH pin at the zero current level ensures asmooth transition to the newly selectedmode. Multiple LTC3871s can be daisy chained

to run out of phase to provide more outputcurrent without increasing input and output

voltage ripple. The SYNC pin allows tosynchronize to the CLKOUT signal ofanother LTC3871. The CLKOUT signal canbe connected to the SYNC pin of thefollowing device stage to line up both thefrequency as well as the phase of the entiresystem. A total of 12 phases can be daisychained to run simultaneously out-of-phasewith respect to each other. The demonstration circuit DC2348A

shown in Figure 3 can be configured withtwo or four phases utilizing one or twoLTC3871 devices. The four phase versionoperating in buck mode has an inputvoltage range of 30 V to 75 V andproduces a 12 V output at up to 60 A.When operating in boost mode, the inputvoltage is from 10 V to 13 V and producesa 48 V at up to 10 A.The LTC3871 efficiency curves in Figure

4 are representative of a four-phase demoboard design using two LTC3871 devices.The buck mode curve steps the 48 V downto 12 V at up to 60 A, while the boostcurve steps up the 12 V to 48 V at up to10 A. Both operate with 97 % peakefficiencies.In buck mode, the LTC3871 includes

current fold-back protection to limit powerdissipation in an over current condition orwhen the VLOW is shorted to ground. If theVLOW falls below 85 % of its nominal output

level, then the maximum sense voltage isprogressively lowered from its maximumprogrammed value to one-third of themaximum value. Foldback current limiting isenabled during soft-start. Under short-circuitconditions with very low duty cycles, theLTC3871 will begin cycle skipping in orderto limit the short-circuit current. In a typical boost controller, the

synchronous diode or the body diode ofthe synchronous MOSFET conducts currentfrom the input to the output. As a result, anoutput (VHIGH) short will drag the input (VLOW)down without a blocking diode or MOSFETto block the current. The LTC3871 uses anexternal low RDS(ON) P-channel MOSFET forinput short-circuit protection when VHIGH isshorted to ground. In normal operation, theP-channel MOSFET is always on, with itsgate-source voltage clamped to 15 Vmaximum. When the UVHIGH pin voltagegoes below its 1.2 V threshold, the FAULTpin goes low 125 � s later. At this point, thePGATE pin turns off the external P-channelMOSFET.

ConclusionThe LTC3871 brings a new level ofperformance, control and simplification to48 V/12 V dual battery DC/DC automotivesystems by allowing the same externalpower components to be used for step-down and step-up purposes. It operates ondemand in buck mode from the 48 V busto the 12 V bus or in boost mode from 12V to 48 V. Up to 12 phases can beparalleled for high power applications andwhen starting the car or when additionalpower is required, the LTC3871 allows bothbatteries to supply energy simultaneouslyto the same load. The additional 48 Vbattery running a portion of a vehicle’selectrical system will play a central role inincreasing available energy, while reducingwiring harness weight and losses. Thisadditional energy capacity paves the wayfor new technologies, enabling cars to besafer and more efficient, all while loweringits CO2 emissions.

Figure 4: Buck(left) and boost(right) efficiencycurves with afour-phasedesign

Figure 3:LTC3871 four-phase demoboard


PRODUCT UPDATE 31

High Power Density DC/DC PoL Converters

Linear Technology offers now the LTC3871, a 100 V/30 V bidirectional twophase synchronous buck or boost controller, ideal for 48 V/12 V automotivedual battery systems. Current 12 V automotive systems are reaching their 3kW power limit due to the increasing demand for more electrical devices. Anewly proposed standard, LV148, combines a secondary 48 V bus with theexisting 12 V system. The 48 V rail includes a belt starter generator (BSG) oran integrated starter generator (ISG), a 48 V lithium-ion battery and abidirectional DC/DC converter for delivery of up to 10 kW of available energyfrom the 48 V and 12 V batteries combined. This technology is targeted forconventional internal combustion automobiles, as well as hybrid electric andmild hybrid vehicles. The LTC3871 operates in buck mode from the 48 V busto the 12 V bus or in boost mode from 12 V to 48 V. Either mode isconfigured on demand with an applied control signal. Up to 12 phases can beparalleled and clocked out-of-phase to minimize input and output filteringrequirements for high current applications (up to 250 A). Its current modearchitecture provides current matching between phases when paralleled. Up to3 kW can be supplied in buck mode or in boost mode with a 12-phasedesign.

www.linear.com

48 V/12 V Automotive BidirectionalSynchronous DC/DC Controller

Fairchild Semiconductor, now part of ON Semiconductor, introduced itsSuperFET® III family of 650V N-channel MOSFETs, that meet the higherpower density, system efficiency and reliability requirements of telecom,server, electric vehicle (EV) charger and solar products. According toFairchild SuperFET III technology has the lowest on-resistance in any easydrive version of a Super Junction MOSFET, delivering best-in-classefficiency. It achieves this thanks to advanced charge balancingtechnology which also enables 44 percent lower on-resistance than itsSuperFET II predecessors, in the same package size. A key factor in theSuperFET III’s ruggedness and reliability is its best-in-class body diode.The lower peak drain-source voltage during turn off improves systemreliability in low temperature operation because the breakdown voltagenaturally drops by 5 % at -25ºC junction temperature than roomtemperature and the peak drain-source voltage becomes higher at lowtemperature.

www.fairchildsemi.com/superfet

Toshiba Electronics Europe has expanded its family of automotive powerMOSFETs with the TK1R5R04PB - the first device in its new low-resistanceD2PAK+ package. While the D2PAK+ has the same footprint as aconventional D2PAK (or TO-263) package, it offers reduced packageresistance. This is thanks to a source pin that is much wider near to the mouldsurface than that of a conventional D2PAK. The TK1R5R04PB is rated for 40 V/ 160 A and has a maximum on resistance of 1.5 mΩ. Minimum andmaximum voltage threshold ratings are 2 V and 3 V respectively. Targetapplications for the new device include automotive pumps, fans, DC/DCconverters and load switches. The TK1R5R04PB will conform with AEC-Q101automotive level qualification requirements.

www.toshiba.semicon-storage.com

160 A MOSFET for Automotive Applications


650 V SuperFET IIIMOSFET Family

Murata announced the MYMGK series of miniature non-isolated “Mono Block”type surface mount point-of-load (PoL) DC/DC converters. These convertersare available in two models at 6 A and 20 A. Each version is available with twooutput voltage range options. Typical applications for these converters includepowering FPGAs and CPUs. Across the range control signals include remoteon/off and a power good indication. Safety and protection features includeunder input voltage lock out (UVLO), output short circuit and output over-current. The use of increasingly compute intensive devices such asprogrammable logic, FPGAs and CPU is demanding high reliable powersupplies that have can quickly respond to load variations, good transientresponse, a low core voltage high current supply. Mono Block type MYMGKseries delivers fast transient response with a minimum of external outputcapacitors, this contributes to significantly shrinking the customer’s board size. These efficient converters, typically between 87.8 % to 95 % model and loaddependent, meet the industrial and telecom requirements for size, efficiencyand power density, especially in high temperature operating case.

www.murata.com

Product Pages_0117.qxp_Layout 1 09/02/2017 09:03

32 PRODUCT UPDATE


ON Semiconductor has introduced a highly integrated single chip for thedevelopment of next generation Li-Ion powered products. The LC709501Ftotal Li-Ion battery solution offers broad power and voltage/current outputrange of 5 V, 9 V and 12 V operation, with a maximum charge/dischargecapability of up to 30 W through simple FET selection. The LC709501Fdetermines what type of device is connected and automatically selects thefastest available method for charging. Advanced users can even reprogram theLC709501F to support custom charge/discharge profiles, as well as USB Type-C and PD “Policy Engine” functions. This IC includes integrated fuel gaugefunction, configurable I/O, LED drivers, I?C interface, and pre-drivers forexternal power MOSFETs. A design reference kit is available to realize fast timeto market. The LC709501F supports various output power levels up to 30 W,by changing external MOSFETs. In addition, there is an integrated USB 2.0 FullSpeed host controller. The internal USB host controller supports connectivitywith iOS and Android apps that enable the device to communicate with theconnected smartphone and subsequently make use of its display to showinformation concerning the battery health and the charging process (chargingtime, battery life, number of charging cycles completed). The device workswith the proprietary charging protocols (such as Fast Charge and QualcommQuick Charge™) now being utilized by smartphone manufacturers toaccelerate the charging period.

www.onsemi.com

Charge Controller for Next Generation Power Banks

Extended Power Rangein a MiniSKiiP ModuleVincotech announced a new MiniSKiiP® product line featuring sixpack topology and able to handleup to 200 A, available with the new Mitsubishi gen 7 IGBT chips. These 1200 V MiniSKiiP® PACK 2& 3 modules reduce static losses by 20 %. Designed for industrial and embedded driveapplications, they provide superior EMI behavior and cut overall system costs. With the benefit ofthis extended power range of up to 200 A in the MiniSKiiP® PACK 3 module, it is far more easy forengineers to design flexible, scalable inverters.

www.vincotech.com/PACK-M7

Proton-Electrotex, the Russian manufacturer of power semiconductors andpower stacks, recently released new series of welding diodes – one in ceramichousing and two housingless diodes. All welding diodes can be used inindustrial welding equipment and perfectly suit welding robots. The companyoffers diodes with enhanced average forward current ratings comparing toavailable on the market alternatives. On top of that, all diodes completelycorrespond to industrial standards and requirements including low on-stateand switching losses, low thermal resistance, and high load cycle capability.Application note, data sheets, and additional information can be found on thecompany website.

This March Proton-Electrotex will participate in APEC 2017 conference,which will take place in Tampa, FL, USA. Everyone interested can appoint ameeting with company representatives to have all their questions aboutwelding diodes as well as IGBTs, power thyristors and diodes to be answered.An appointment can be made through a form available at company website.

www.proton-electrotex.com

New series of Welding Diodes

Product Pages_0117.qxp_Layout 1 09/02/2017 09:04

WEBSITE LOCATOR 33


Diodes

Diodes

Discrete Semiconductors

Drivers ICS

EMC/EMI

www.microsemi.comMicrosemiTel: 001 541 382 8028

Ferrites & Accessories

GTO/Triacs

Hall Current Sensors

DC/DC Connverters

www.power.ti.comTexas InstrumentsTel: +44 (0)1604 663399


www.neutronltd.co.ukNeutron LtdTel: +44 (0)1460 242200

Harmonic Filters

www.murata-europe.comMurata Electronics (UK) LtdTel: +44 (0)1252 811666

Direct Bonded Copper (DPC Substrates)

www.curamik.co.ukcuramik� electronics GmbHTel: +49 9645 9222 0

www.mark5.comMark 5 LtdTel: +44 (0)2392 618616

www.dgseals.comdgseals.comTel: 001 972 931 8463


www.digikey.com/europeDigi-KeyTel: +31 (0)53 484 9584

www.dextermag.comDexter Magnetic Technologies, Inc.Tel: 001 847 956 1140


www.protocol-power.comProtocol Power ProductsTel: +44 (0)1582 477737

Busbars

www.auxel.comAuxel FTGTel: + 33 3 20 62 95 20

Capacitors

Certification

www.psl-group.uk.comPSL Group UK Ltd.Tel +44 (0) 1582 676800

Connectors & Terminal Blocks

www.auxel.comAuxel FTGTel: +44 (0)7714 699967

www.productapprovals.co.ukProduct Approvals LtdTel: +44 (0)1588 620192

www.proton-electrotex.com/ Proton-Electrotex JSC/Tel: +7 4862 440642;

www.voltagemultipliers.com Voltage Multipliers, Inc.Tel: 001 559 651 1402

Arbitrary 4-Quadrant PowerSources

www.rohrer-muenchen.deRohrer GmbH Tel.: +49 (0)89 8970120

High Voltage and High PowerElectronics

Dean Technology, Inc.www.deantechnology.com+1 (972) 248-7691

Website Locator.qxp_Website Locator 09/02/2017 10:14

34 WEBSITE LOCATOR


Power Modules

Power Protection Products

Power Semiconductors

Power Substrates

Resistors & Potentiometers

RF & Microwave TestEquipment.

Simulation Software

Thyristors

Smartpower Devices

Power ICs

Power Amplifiers

Switched Mode PowerSupplies

Thermal Management &Heatsinks





www.neutronltd.co.ukNeutron LtdTel: +44 (0)1460 242200

www.rubadue.comRubadue Wire Co., Inc.Tel. 001 970-351-6100



www.irf.comInternational Rectifier Co. (GB) LtdTel: +44 (0)1737 227200


www.fujielectric-europe.comFuji Electric Europe GmbHTel: +49 (0)69-66902920

www.microsemi.comMicrosemi Tel: 001 541 382 8028


www.ar-europe.ieAR EuropeTel: 353-61-504300



www.universal-science.comUniversal Science LtdTel: +44 (0)1908 222211

www.power.ti.comTexas InstrummentsTel: +44 (0)1604 663399


www.dau-at.comDau GmbH & Co KGTel: +43 3143 23510

www.power.ti.comTexas InstrummentsTel: +44 (0)1604 663399


www.isabellenhuette.deIsabellenhütte Heusler GmbH KGTel: +49/(27 71) 9 34 2 82

ADVERTISERS INDEX

Mosfets

Magnetic Materials/Products

Line Simulation

Optoelectronic Devices

Packaging & Packaging Materials


www.citapower.comBias Power, LLCTel: 001 847.419.9118

www.digikey.com/europeDigi-Key Tel: +31 (0)53 484 9584


www.digikey.com/europeDigi-Key Tel: +31 (0)53 484 9584



www.abl-heatsinks.co.ukABL Components LtdTel: +44 (0) 121 789 8686www.hero-power.com

Rohrer GmbH Tel.: +49 (0)89 8970120

www.rohrer-muenchen.deRohrer GmbHTel: +49 (0)89 8970120


APEC ....................................................................................................................................4Dean Technologies ......................................................................................................24Drives & Controls 2018..............................................................................................17Fuji Electric .....................................................................................................................IFCGraftech ..............................................................................................................................8HKR ...................................................................................................................................19LEM ...................................................................................................................................21

PCIM ................................................................................................................................IBCPower Electronics Measurements...........................................................................18Proton..................................................................................................................................9ROHM...............................................................................................................................11Semikron......................................................................................................................OBCSmart Machines & Factories .....................................................................................22VMI ....................................................................................................................................18




IGBTs

www.microsemi.comMicrosemi Tel: 001 541 382 8028


Website Locator.qxp_Website Locator 09/02/2017 10:14

International Exhibition and Conferencefor Power Electronics, Intelligent Motion,Renewable Energy and Energy ManagementNuremberg, 16 – 18 May 2017

»Connecting Global PowerYou are the expert, we have the platform. Position yourself among top-class industry leaders und present your know-how.

More information at: +49 711 [email protected]

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Become exhibitor and meet a competent,

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Silicon Carbide Power Modules

Leading Chip and Packaging Technology for Highest Energy Effi ciency

10kW up to 350kWIncreased switching frequencies enable optimisation and cost down of fi lter components

Reduced power losses lead to increased effi ciency and lower system cost and size through smaller cooling devices

Latest SiC chips of the leading suppliers

Various packages and connection technologies with optimised chipsets for your application

www.semikron.com shop.semikron.com

210x297

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dual battery require bi-directional dc/dc controllers · of compound semiconductors. silicon...

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