Is it the End of the Road for Silicon in Power Conversion ...€¦ · IEEE-BCTM 2011 Is it the End...
Transcript of Is it the End of the Road for Silicon in Power Conversion ...€¦ · IEEE-BCTM 2011 Is it the End...
IEEE-BCTM 2011
Is it the End of the Road for
Silicon in Power Conversion?
Paper 7.1
Is This the End of The Road for
Silicon in Power Conversion? Alex Lidow PhD
Efficient Power Conversion Corporation
909 N. Sepulveda Blvd.
El Segundo, California 90245
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• Why Gallium Nitride?
• Breaking down the barriers
• What the future might hold
• Conclusion
Agenda
Smaller Die Sizes
Why Gallium Nitride?
0
1000
2000
3000
EPC1010 Si7462DP FDMS2672 IRF6641
FOM = Rdson x Qg (200V)
Better Figure of Merit
Why Gallium Nitride?
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Dielectric
GaN
- - - - - - - - - - - - - - -
Si
AlGaN Electron Generating Layer
Aluminum Nitride
Isolation Layer
D G S - - - -
eGaN FET Structure
Two Dimensional
Electron Gas (2DEG)
GaN
Silicon
G G Source
Drain
Metal 2
Metal 3
Via 2 Metal 1
Passivation
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eGaN FET Structure
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Flip Chip Assembly
HEATSINK
Breaking Down the Barriers
• Does it enable significant new capabilities?
• Is it easy to use?
• Is it VERY cost effective to the user?
• Is it reliable?
Breaking Down the Barriers
• Does it enable significant new capabilities?
• Is it easy to use?
• Is it VERY cost effective to the user?
• Is it reliable?
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Buck Converter
Advantage:
• High power density
and high efficiency
Efficiency vs Frequency @
1.2Vout / 5A
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62%
64%
66%
68%
70%
72%
74%
76%
78%
80%
82%
84%
86%
88%
90%
92%
300 400 500 600 700 800
Effi
cie
ncy
(%)
Switching Frequency (kHz)
MOSFET @ 12Vin
MOSFET @ 24Vin
MOSFET @ 48Vin
eGaN FET @ 12Vin
eGaN FET @ 24Vin
eGaN FET @ 48Vin
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12VIN – 1.2 VOUT Buck Converter
Efficiency at 1 MHz
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Isolated Full Bridge Converter
Advantage:
• Isolation and high power
density at high power 36~75 V
12 V
15 A
180 W
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Efficiency comparison @ 12 VOUT
eGaN FET @ 333 kHz vs MOSFET @ 250 kHz
Isolated Full Bridge Converter
0
10
20
30
40
50 500
Gai
n (d
B)
Frequency [MHz]
EPC1012 Maximum Gain Vs Frequency
High Frequency Capabilities
1000
16
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High Frequency Capabilities
Breaking Down the Barriers
• Does it enable significant new capabilities?
• Is it easy to use?
• Is it VERY cost effective to the user?
• Is it reliable?
It’s just like a MOSFET
Is it easy to use?
except for TWO things
(1)
The high frequency capability makes circuits
using eGaN FETs sensitive to layout
(2)
eGaN FETs have a lower maximum gate voltage
than power MOSFETs
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Integrated Gate Driver Solution
LM5113 from National Semiconductor
Breaking Down the Barriers
• Does it enable significant new capabilities?
• Is it easy to use?
• Is it VERY cost effective to the user?
• Is it reliable?
Silicon Vs eGaN Wafer Costs
Starting Material
Epi Growth
Wafer Fab
Test
Assembly
OVERALL
2010 2015
same same
higher
same
same
lower
lower
same
lower
~same?
lower! higher
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Breaking Down the Barriers
• Does it enable significant new capabilities?
• Is it easy to use?
• Is it VERY cost effective to the user?
• Is it reliable?
Reliability Key Issues
• Current Collapse
• Temperature Cycling and Humidity Sensitivity
• Operating Life
Reliability Key Issues
• Current Collapse
• Temperature Cycling and Humidity Sensitivity
• Operating Life
No Current Collapse
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 500 1000 1500 2000 2500 3000
No
rmal
ize
d R
DS(
ON
)
Stress Hours
HTRB 150C EPC1010 RDS(ON)
Reliability Key Issues
• Current Collapse
• Temperature Cycling and Humidity Sensitivity
• Operating Life
TC and H3TRB
0.0010
0.0015
0.0020
0.0025
0.0030
0.0035
0.0040
0 200 400 600 800 1000
RD
S(O
N) (o
hm
)
Stress Hours
EPC2015 RDS(ON) after 40V at 85oC/85%RH
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 200 400 600 800 1000
No
rmal
ize
d R
DS(
ON
)
Stress Cycles
EPC2001 RDS(ON) after TC -40 to 125oC
Reliability Key Issues
• Current Collapse
• Temperature Cycling and Humidity Sensitivity
• Operating Life
Operating Life
0.9
0.95
1
1.05
1.1
0 500 1000 1500 2000No
rmal
ize
d E
ffic
ien
cy
Stress Hours
EPC9002 Efficiency after Op Life Test at 85oC
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25
100
250400
1.00
10.00
100.00
1000.00
0 200 400 600 800 1000 1200 1400
Rat
ed
RD
S(O
N)m
W
Rated VDSS(MAX)
2009
2011
2012
EPC’s eGaN FET products will extend to 600V in 2011 and to
900V and 1200V in 2012 if there is adequate customer interest
Beyond 600 Volts
100 mW
5x6mm
PQFN
400 mW
5x6mm
PQFN
250 mW
5x6mm
PQFN
150 mW
8x8mm
PQFN
90 mW
8x8mm
PQFN
LGA
Package
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Driver On Board
Beyond Discrete Devices
Full-Bridge with Driver and Level Shift
Discrete FET with Driver
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Is it the end of the road for
Silicon?
• Many new applications are enabled due to
quantum leap in frequency capability
• Devices are easy to use because they are
similar to a power MOSFETs and
commercial IC drivers are available
• The technology will soon be lower cost-
per-function than silicon.
• Reliability testing shows that parts are
capable in commercial applications.
The end of the road
for silicon…..
is the beginning of
the eGaN FET
journey!
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