EPC - The Leader in eGaN ® FETs |
Efficient Power Conversion Corporation
The eGaN® FET Journey Continues
GaN Transistors for Efficient Power Conversion Alex Lidow
CEO
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Agenda
• The GaN Journey Begins
• Enhancement Mode GaN FETs
• Improving Power Conversion Efficiency
• What is in the future?
2
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
The Ideal Power Switch
• Block Infinite Voltage
• Carry Infinite Current
• Switch In Zero Time
• Zero Drive Power
• Normally Off
3
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Material Comparison
4
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Material Comparison
5
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
GaN vs SiC Comparison
Pro GaN • GaN mobility almost 3 times SiC • GaN on silicon can be manufactured in a standard silicon
foundry on large diameter wafers • GaN-on-silicon starting material can be much lower cost
than SiC • Monolithic integration of multiple power and analog
devices is straightforward Pro SiC • SiC thermal conductivity is 3 times GaN • SiC vertical devices may be more straightforward to
manufacture than GaN-on-silicon 6
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
GaN Market Projection
Total = $350M for GaN in 2015
Source: Yole Development
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
How Does a GaN HEMT Work?
8
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
GaN + AlGaN
AlGaN
GaN
Spontaneous Polarization
9
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Device Construction Concept
GaN
Substrate
Drain
Protection Dielectric
Source
Gate AlGaN
10
AlN Buffer
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Normally ON Devices
S D G
11
In a normally ON device the 2DEG can only be removed under the gate electrode when a negative gate voltage is applied
relative to the source
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Normally Off Devices – eGaN®FETs
S D G
12
At zero volts on the gate the 2DEG is depleted under the enhancement mode gate electrode and is restored by a
positive voltage on the gate relative to the source
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
SEM of an eGaN® FET
eGaN® Is A Registered Trademark Of The Efficient Power Conversion Corporation 13
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
On Resistance vs Temperature
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
-50 -25 0 25 50 75 100 125 150
Nor
mal
ized
On
Resi
stan
ce
Junction Temperature (°C)
GaN
MOSFET B
About 20%
Difference At 125 °C
14
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Threshold vs Temperature
0.6
0.7
0.8
0.9
1
1.1
1.2
-50 -25 0 25 50 75 100 125 150
Nor
mal
ized
The
rsho
ld V
olta
ge
Junction Temperature (°C)
GaN
MOSFET A
15
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
eGaN®FET Reverse Conduction
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Total Gate Charge
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35
Gat
e-To
-Sou
rce
Volta
ge (
V)
Total Gate Charge (nC)
MOSFET A
MOSFET B
GaN
17
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Figure of Merit
0
100
200
300
400
500
EPC2001 BSC109N10NS3 IRFH5030 SiR870DP FDMS86101
FOM = Rdson x Qg (100V)
18
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Package Wish List
• Low parasitic resistance
• Low parasitic inductance
• Low thermal resistance
• Small size
• Low cost
19
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs | 20
Flip Chip LGA Assembly
HEATSINK
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
LGA Construction
Gate
Substrate
Source Contacts
Drain Contacts
21
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Size Comparison
D-PAK
eGaN FET
Drawn To Scale
5.76 mm²
65.3 mm²
22
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Package Inductance
23
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Package Resistance
24
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
The Opportunity to Improve DC-DC Efficiency
25
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Integrated Gate Driver Solution
LM5113 from Texas Instruments
26
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Buck Converter
Advantage: • High power density
and high efficiency
27
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Efficiency vs Frequency
62%
64%
66%
68%
70%
72%
74%
76%
78%
80%
82%
84%
86%
88%
90%
92%
300 400 500 600 700 800
Effi
cien
cy (%
)
Switching Frequency (kHz)
MOSFET @ 12Vin
MOSFET @ 24Vin
MOSFET @ 48Vin
eGaN FET @ 12Vin
eGaN FET @ 24Vin
eGaN FET @ 48Vin
1.2 Vout / 5A
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Parallel FET Buck Converter Efficiency at 1 MHz
12 VIN – 1.2 VOUT
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Buck Size Comparison
A 24V-1.2V Buck converter was built with both with eGaN FETs and state-of-the-art silicon power MOSFETs
30
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Buck Size Comparison
184 mm2
31
The MOSFET-based circuit measures 184 mm2
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Buck Size Comparison
121 mm2
A 24V-1.2V Buck converter with eGaN FETs is 50% smaller and has 30% less power losses at 800 kHz.
32
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Isolated Full Bridge Converter
Advantage: • Isolation and high power
density at high power 36~75 V
12 V 15 A 180 W
~48 V ~53V
700 W 2-phase
33
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Isolated Full Bridge Converter
34
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
84%
86%
88%
90%
92%
94%
96%
0 2 4 6 8 10 12 14 16
Effi
cien
cy
Output Current (A)
36 V eGaN FET
36 V MOSFET
48 V eGaN FET
48 V MOSFET
60 V eGaN FET
60 V MOSFET
eGaN FET @ 333 kHz vs MOSFET @ 250 kHz
Isolated Full Bridge Converter
35
VOUT = 12 V
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
PoE-PSE Full Bridge Converter
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
88%
89%
90%
91%
92%
93%
94%
95%
96%
97%
98%
0 2 4 6 8 10 12 14
Effic
ienc
y
Output Current (A)
38 V eGaN FET 38 V MOSFET
48 V eGaN FET 48 V MOSFET
60 V eGaN FET 60 V MOSFET
140 kHz MOSFET
250 kHz eGaN FET
550 W
700 W
37
PoE-PSE Full Bridge Converter
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
88%
89%
90%
91%
92%
93%
94%
95%
96%
97%
98%
0 2 4 6 8 10 12 14
Effic
ienc
y
Output Current (A)
38 V Two phase 38 V Single phase
48 V Two phase 48 V Single phase
60 V Two phase 60 V Single phase
38
PoE-PSE Full Bridge Converter
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Paralleling eGaN®FETs
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Half-Bridge Topologies
Q1a
Q2a
Gate Driver
Gate Driver
. . .
Q1b Q1n
Q2b Q2n
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Introducing the PIF
• Based on minimum switching time that maintains dv/dt and di/dt immunity
• Normalizes evaluations relative to a single FET
• Can be used to predict switching performance
41
Note: dvx/dt and dix/dt are in units of time
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Half Bridge Layout Evaluations
D E B C A
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
PIF for Half Bridge Layouts
2 Devices in Parallel 4 Devices in Parallel
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D E B C A
43
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Best Layout Configuration
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©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Four FETs Operating in Parallel
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
What’s in the Future?
46
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
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?
47
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
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?
48
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
• Wireless Power Transmission – GaN Enabled
• RF DC-DC “Envelope Tracking” – GaN Enabled
• RadHard
• Power Over Ethernet
• RF Transmission
• Network and Server Power Supplies
• Power Factor Correction
• Point of Load Modules
• Solar Microinverters
• Energy Efficient Lighting
• UPS Systems
• Class D Audio
49
Applications for eGaN® FETs
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
0
10
20
30
40
50 500
Gai
n (d
B)
Frequency [MHz]
EPC1012 Maximum Gain Vs Frequency
High Frequency High Voltage and High Power
1000
EPC 2012 Maximum Gain vs Frequency 200 V eGaN FETs
50
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Wireless Power
51
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
RF Envelope Tracking
0
10
20
30
40
50
60
70
PA Ef
ficie
ncy (
%)
Peak PowerAverage Power
Output Power (dBm)
Output Probability
52
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
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?
53
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
It’s just like a MOSFET
Is it easy to use?
except
The high frequency capability makes circuits using eGaN FETs sensitive to layout
The lower VG(MAX) of 6 V makes it advisable to have VGS
regulation in your gate drive circuitry
The ultra-small LGA increases the concentration of heat on the PCB
54
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
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?
55
EPC - The Leader in eGaN ® FETs |
Silicon vs eGaN® FET Wafer Costs
Starting Material
Epi Growth
Wafer Fab
Test
Assembly
OVERALL
2011 2015
same same
higher
same
same
lower
lower
same
lower
~same?
lower! higher
56
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
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?
57
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
eGaN® FETs are Reliable
58
00.20.40.60.8
11.21.41.61.8
2
0 200 400 600 800 1000
Nor
mal
ized
Rds
on
Stress Hours
EPC2001 RDS(ON) after 100VDS HTRB at 125oC
00.20.40.60.8
11.21.41.61.8
2
0 200 400 600 800 1000
Vth
(V)
Stress Hours
EPC2001 VGS(TH) after 100VDS HTRB at 125oC
0.0E+00
1.0E-04
2.0E-04
3.0E-04
4.0E-04
5.0E-04
0 200 400 600 800 1000
Idss
@40
V (A
)
Stress Hours
EPC2015 Idss after 40V H3TRB at 85oC/85%RH
datasheet spec: 500uA max
0.9
0.95
1
1.05
1.1
0 1000 2000 3000
Nor
mal
ized
Effic
ienc
y
Stress Hours
EPC9001 Efficiency after Op Life Test at 85oC TJ
board a
board b
board c
board d
board e
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
59
47
25
100
250400
1.00
10.00
100.00
1000.00
0 200 400 600 800 1000 1200 1400
Rat
ed R
DS(
ON
)m
Ω
Rated VDSS(MAX)
Beyond 600 Volts
500 mΩ 5x6mm PQFN
150 mΩ 8x8mm PQFN
90 mΩ 8x8mm PQFN
LGA Package
59
EPC - The Leader in eGaN ® FETs |
Driver On Board
Beyond Discrete Devices
Full-Bridge with Driver and Level Shift
Discrete FET with Driver
60
©2012 Efficient Power Conversion Corporation EPC - The Leader in eGaN ® FETs |
Summary
• eGaN FETs are straightforward to use, but care must be taken due to the higher switching speeds compared with power MOSFETs
• eGaN FETs will replace silicon power MOSFETs in power conversion applications with a low-cost and higher efficiency solution
• Higher voltage devices and the integration of analog plus power will enhance the performance and cost-effectiveness of eGaN FETs
61
EPC - The Leader in eGaN ® FETs |
The end of the road for silicon…..
is the beginning of
the eGaN FET journey!