809pet Silicon Carbide Mosfets Igbt

7/29/2019 809pet Silicon Carbide Mosfets Igbt

1/5 www.powerelectronics.com

In light o recent silicon carbide (SiC) technology advances, commercial production o

1200-V 4H-SiC[1]power MOSFEs is now easible. Tere have been improvementsin 4H-SiC substrate quality and epitaxy, optimized device designs and abricationprocesses, plus increased channel mobility with nitridation annealing.[2] SiC is abetter power semiconductor than Si, because o a 10-times higher electric-eldbreakdown capability, higher thermal conductivity and higher temperature opera-

tion capability due to a wide electronic bandgap.SiC excels over Si as a semiconductor material in 600-V and higher-rated breakdown

voltage devices. SiC Schottky diodes at 600-V and 1200-V ratings are commercially avail-able today and are already accepted as the best solution or eciency improvement in boost

converter topologies. In addition, these diodes nd use in solar inverters, because they have lowerswitching losses than the Si PIN reewheeling diodes now used in that application.

At 600-V and 1200-V ratings, IGBs have been the switch o choice or power conversion. Previously,Si MOSFEs were handicapped in those applications by their high on-resistance (RDSON). At high breakdownvoltages, RDSON increases approximately with the square o the drain-source breakdown voltage VDSMAX.

[3]Te RDSON o a MOSFE consists o the sum o the channel resistance, the inherent JFE resistance

and the dri resistance (Fig. 1). Te dri resistance (RDRIF

) is the dominant portion o the overallresistance, where d equals dri-layer thickness, q equals electron charge, n equals channel

mobility and ND

equals doping actor.Te new generation o SiC MOSFEs cuts dri-layer thickness by nearly a ac-

tor o 10 while simultaneously enabling the doping actor to increase by the same order omagnitude. Te overall eect results in a reduction o the dri resistance to 1/100th o its Si

MOSFE equivalent.he improved SiC MOSFE

discussed here is an engineeringsample o a 1200-V, 20-A devicewith a 100-mV RDSON at a 15-Vgate-source voltage. Besides its in-herent reduction in on-resistance,SiC also oers a substantiallyreduced on-resistance variationover its operating temperature.From 25C to 150C, SiC varia-tions are in the range o 20%,compared with 200% to 300% orSi. Te SiC MOSFE die is capableo operation at junction tempera-tures greater than 200C, but theengineering sample is limited in

By Michael ONeill,Applications Engineering Manager, CREE, Durham, N.C.

SiC technoog has undergone signifcantimprovements that now aow abricationo MOSFETs capabe o outperormingtheir Si IGBT cousins, particuar at highpower and high temperatures.

SiliconCarbide

Challenge

14

Fig. 1. Cross-section o DMOSFET power transistor shows its

resistive components: the channel resistance, the inherent

JFET resistance and the drit resistance that combine to

produce a relatively high on-resistance.

Ni

Ni

N+

Source

P-well

N type substrate

Gate metal

Gate oxide

RCHANNEL

RJFET

RDRIFT

P+

Ni

N+

Source

P-well

P+

RDRIFT =d

qnND


2/5www.powerelectronics.com Power Electronics Technology September 200815

temperature to150C by its O-247 plastic package.Compared with a Si IGB, a SiC MOSFE has a substan-

tial advantage in conduction losses, particularly at lowerpower outputs. By virtue o its unipolar nature, it has no tailcurrents at turn-o, thereby leading to greatly reduced turn-o losses. able 1 shows the switching loss dierence whencompared with a standard o-the-shel 1200-V IGB.

Te switching losses o a SiC MOSFE are less than halthose o a Si IGB (1.14 mJ versus 2.6 mJ, respectively). Com-bining this switching-loss reduction with the lower overallconduction losses, it is clear that the SiC switch is a muchmore ecient device or high-power-conversion systems.

Three-Phase Solar Invertero demonstrate its application as a solar inverter, a 7-kW,

16.6-kHz three-phase grid-connected system was imple-mented. Tis B6 topology, developed by the FraunhoerInstitute ISE, uses a split-link dc capacitor with a connectiono the neutral conductor to the center point o both capaci-

tors. Te unit connects to a 400-V grid, using 1200-V IGBsas the standard power-conversion devices. Tese IGBswere replaced by 1200-V SiC MOSFEs, and the signicantperormance dierence is clearly visible in Fig. 2. able 2shows the maximum eciency and European-eciencyimprovements that were achieved.

As seen by the Fig. 2 curves, the SiC devices oer a peror-mance advantage over their Si IGB counterparts. Maximumeciency increased by 1.92%, and the overall Euro-eciencyrating improved by 2.36%. Tis equates to a 50% reductionin overall losses in the system.

Another perormance-parameter improvement o notewas the systems reduction in heatsink temperature at ull-rated power output. At a 25C ambient, the nal steady-stateheatsink temperature with the IGBs was 93C versus 50Cwith the SiC MOSFEs.[3]

Tere are several dierent ways o looking at the systembenets obtainable by using a ull SiC-based solution in aphotovoltaic (PV) power converter:

lCost o inductive components. Te volume o an induc-tive component depends most signicantly on the systemswitching requency. A good approximation is a reduction

Fig. 2. Comparison o 1200-V SiC DMOSFET and 1200-V Si IGBT

eciencies in a three-phase inverter shows that at the same

voltage rating, the higher-eciency SiC DMOSFETs provide a

perormance advantage over their Si IGBT counterparts.[3]

Table 1. Switching loss comparison.[2] Table 2. Measured eciencies (single-phase inverter).[2]

Max. eiciency (h) Euro eiciency*

Fairchild IGBT hMAX

= 95.89% hEURO

= 95.07%

CREEs SiCDMOSFET

hMAX

= 97.81% hEURO

= 97.43%

Efficiency gain DhMAX

= 1.92% DhEURO

= 2.36%

*hEURO

= 0.03 h5%

+ 0.06 h10%

% + 0.13 h20%

+ 0.1 h30%

+ 0.48 h50%

+ 0.2 h100%

.

EIGBT, 1200-V

Infneon BSM 15GD120 DN2

ID

(max.) = 15 A at 80C

SiC DMOSFET,1200-V

CREE engineeringsample

ID

(max.) = 10 A at25C to 150C

VDS

600 V 800 V

Load Inductive Inductive(L

L= 500 H )

VGE

15 V 0 V/15 V

RG

82 V 10V

EON

at ID

= 10 A 1.6 mJ 0.8 mJ

EOFF

at ID

= 10 A 1.0 mJ 0.34 mJ

close to the reciprocal o the times actor increase in switch-ing requency, taking into account lling actor and windingtechnique. Te cost o inductive components decreases byabout 50% or a two to three times increase in switchingrequency (which is entirely possible with this technology).o keep the third harmonic beneath the lower conductedemission foor o 150 kHz, the practical limit or hardswitching is just below 50 kHz in these systems.

l Reduced cooling requirements. Reductions o up to50% or more in heatsink temperature are possible withthis technology. A comparable reduction in heatsink siz-

ing is possible while still maintaining the higher-eciencyadvantage that this technology enables. Tis solar inverterexample o reduction in heatsink sizing should allow areduction in production cost o around 5%, while stilldelivering increased annual benet through eed-in tarisrom the grid. A eed-in tari is an incentive structureto encourage the adoption o renewable energy throughgovernment legislation.

lAnnual eed-in beneft. A common PV system with7 kW in Germany produces approximately 7000 kWh peryear with a eed-in tari o 0.49 euro/kWh. (In June 2008, theeuro approximately was worth US$1.60.) Te annual benet

is approximately 3430 euros. Te three-phase inverter givenin the previous example showed an increase in Euro eciencyo 2.36%. Tis equates to an annual gain o 81 euros per yearwith this particular system. Tis is the estimation or centralEurope. However, i looking at southern Europe, where the

0 1000 2000 3000 4000 5000 6000 7000

AC power (W)

Efficiencyfactor(%)

98

97

96

95

94

93

92

91

90

1200-V SiC-DMOS

1200-V IGBT module


3/5Power Electronics Technology September 2008 www.powerelectronics.com16

SiC TECHNOlOGy

achieve the same goal with only two switches. When switchesS1 and S2 are turned on, the stored energy in C1 to C3 isquickly moved to the secondary-side resonant capacitor(C

D) through the transormer (

R) and resonant inductor

(LR). Te discharging time is designed to be approximately

equal to one-hal o the resonant period (O). For an optimal

design, O

should be relatively shorter than the switchingperiod (

S) to achieve a low total harmonic distortion.

Fig. 3. Three-phase 3-kW, HPF, two-switch orward converter

initially employed 1200-V IGBTs, which were replaced by 1200-V

SiC DMOSFETs that improved system eciency.[5]

Fig. 4. Eciency prole comparison at 67 kHz shows a higher

SiC eciency at 3-kW output and throughout the entire

load curve, as well as a case-temperature reduction with the

MOSFETs relative to the IGBTs.[5]irradiation level is about twice that in Germany, the annual

benet can be even greater, as shown in a table in the onlineversion o this article.[4]

Three-Phase High-Power-Factor RectiferA three-phase six-switch rectier ollowed by an isolated

dc-dc converter is typically used in three-phase applicationsthat require high power actor (HPF) and galvanic isolationbetween input and output. Te rectier shown in Fig. 3(a 3-kW zero current switching resonant topology) can

LA

LF

LR

N2

TR

N1

VAN

VBN

VCN

LB

C1CD

DD

+

CFR

D1

DF

VO

D2 D3

DC1

DC2

S2

S1

D4 D5 D6

C2

C3

LC

Tape Wound Cores

Bobbin Cores

Cut Cores

Kool Mu Cores

Molypermalloy Cores

High Flux Cores

XFLUX

Power Materials

High Permeability MaterialsSpecial Materials

Strip Wound Cores

Powder Cores

Ferrite Cores

110 Delta DrivePittsburgh, Pa 15238

Toll-Free: 1 800 245 3984Phone: 412 696 1333Fax: 412 696 0333

Web: www.mag-inc.comEmail: [email protected]

Magnetics Hong Kong

Asia Sales and Service

Phone: +852 3102 9337

Fax: +852 3585 1482

Email: [email protected]

0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0

Output power (kW)

fSMAX= 67 kHz

2.2%

Efficiencyfactor(%)

92

90

88

86

84

82

80

CREE SiC MOSFET2x10 A, 1200 V

FGA25N120

25-A IGBT

FGL40N120

40-A IGBT


4/5

17www.powerelectronics.com Power Electronics Technology September 2008

SiC TECHNOlOGy

Te system was run initially at ull load with a pair o

standard 1200-V, 25-A-rated IGBs. Tese devices were thenreplaced by a pair o standard 1200-V, 40-A IGBs, and thesystem was re-run at ull load. Te eciency versus outputpower curves were recorded.

he IGBs were then replaced by a pair o 1200-V,20-A-rated SiC MOSFEs and the exercise repeated. Asseen in Fig. 4, the SiC devices resulted in a 2.2% increasein eciency at a 3-kW output and substantial eciencyimprovement throughout the entire load curve. Also o notewas a 25C case-temperature reduction with the MOSFEsversus the 40-A-rated IGBs and a 36C dierence when

compared with the 25-A-rated devices.[5]

10-kV, 10-A SiC MOSFET in a Boost ConverterSiC technology shows signicant improvements in the

1200-V MOSFE arena, as revealed in the two previousexamples. Te perormance improvement becomes evengreater when compared to Si power switches rated at6.5 kV and above.

Recently developed was a 10-kV, 10-A SiC MOSFE.Te 10-kV device exhibits a drain-source orward voltagedrop o only 4.1 V, while conducting ull-rated 10-A draincurrent with a 20-V gate-source voltage. Tis is equivalent

to a specic on-resistance characteristic o only 127 mV/cm2. Te drain-source leakage current measured 124 nAat a 10-kV blocking voltage. In a direct comparison with astandard 6.5-kV Si IGB in a clamped inductive switchingtest xture, a SiC MOSFE exhibited 1/200th o the totalswitching energy o the IGB. Tis unipolar SiC MOSFEsturn-on delay time was only 94 ns compared with 1.4 sor the IGB and the turn-o time was only 50 ns insteado the IGBs 540 ns.

o analyze in-circuit perormance, a 10-kV SiC MOSFEwas combined with a 10-kV SiC Schottky diode and anair-core inductor in a standard boost-circuit topology(Fig. 5). Te circuit was designed to boost a 500-Vdc inputto a 5-kVdc output at a switching requency o 20 kHz. Tesystem ran at 91% eciency throughout the power band up

Fig. 5. Result o a 10-kV SiC MOSFET combined with a 10-kV

SiC Schottky diode and an air-core inductor in a boost

circuit that accepts a 500-Vdc input and produces a 5-kVdc

output, at 20-kHz switching requency.[6]

Power Modules

for Solar Inverters

98,8% European efficiencyat 3kW nominalCompact flow0 housing

Further dedicated designs forisolated and three-level solartopologies are available.

Power Modules

www.vincotech.com

Main Features

P89x family

NEW flowSOL 0 BI family fornon-isolated topologies

Input

VIN = 503 V

IIN = 1.35 A

PIN = 679 W

Output

VOUT= 5 kV

IOUT = 0.12 APOUT = 617 W

Duty cycle

90%

10-A, 10-kV SiC Schottky diode 10-A, 10-kV SiC MOSFET


5/5www.powerelectronics.com Power Electronics Technology September 200819

to 600 W. Considering that this same circuit with standardSi MOSFE switches would only be capable o running ata ew hundred Hertz switching requency, there is an evengreater perormance advantage with SiC material at thesevoltage levels. Te waveorm shown in Fig. 6 exhibits theexceptionally ast turn-o transient o this system.[6]

With the most recent advancements in SiC materialsprocessing and device design, it will soon be possible toproduce reliable MOSFE switches or the commercialmarketplace. Considering the recent surge in interest in

alternative energy systems, SiC technology is now ready tourther improve their benets. Te reduction in power lossesthat this technology will provide in a PV systems powerconversion section will enable more ecient usage o PVpanel energy, in turn providing more power to the grid andallowing a reduction in uture ossil-uel generation. PETech

Reerences1. 4H reers to the SiC crystalline structure used in powersemiconductors.2. Hull, Brett, et al. Status o 1200 V 4H-SiC Power DMOS-FEs, International Semiconductor Device Research Sym-

posium, December 2007.3. Burger, B.; Kranzer, D.; Stalter, O.; and Lehrmann, S.Silicon Carbide (SiC) D-MOS or Grid-Feeding Solar-In-verters, Fraunhoer Institute, EPE 2007, September 2007.4. Burger, B.; Kranzer, D.; and Stalter, O. Cost Reduction oPV Inverters with SiC DMOSFEs, Fraunhoer Institute, 5thInternational Conerence on Integrated Power ElectronicsSystems, March 2008.5. Yang, Yungtaek; Dillman, David L.; and Jovanovic, MilanM. Perormance Evaluation o Silicon Carbide MOSFE inTree-Phase High-Power-Factor Rectier, Power Electron-ics Laboratory, Delta Products, www.deltartp.com.6. Das, Mrinal K., et al. State-o-the-Art 10-kV NMOSransistors, 20th Annual International Symposium onPower Semiconductor Devices and ICs, May 2008.

Fig. 6.A 10-kV SiC MOSFET running at 20 kHz and dissipating

600 W exhibited about 1.5-s drain current turn-of transient.[6]

SiC TECHNOlOGy

11 11.1 11.2 11.3 11.4

Time (s)tDOFF

= 50 ns tFALL = 94 ns

VDS

(kV)

ID(

A)

VGS

(V)

6

5

4

3

2

1

0

1

30

25

20

15

10

5

0

5

VDS

ID

VGS

flowPACK 2 3rd genup to 150A at 1200V

High Power

Sixpacks forMotor Drives

IGBT4 technology for lowsaturation losses andimproved EMC behavior

Low inductance layoutand compact design

High powerflow

2 housing

Power Modules

www.vincotech.com

NEW

Main Features

P68X series

809pet Silicon Carbide Mosfets Igbt

Documents

Transcript of 809pet Silicon Carbide Mosfets Igbt