Presentation GaN Gallium Nitride APEC 2016 01_00 | Apr 14, 2016 | PDF | 1.43 mb

GaN in a Silicon world:
competition or coexistence?
Tim McDonald
GaN Technology Development
Worldwide Applications and Marketing
Infineon Technologies
Eric Persson, Andrea Bricconi, Felix Grawert
APEC 2016, Long Beach, CA
Abstract
Significant development resources have been expended and
Gallium Nitride (GaN) based power conversion devices are
now being introduced to the market on the heels of much
hype. It remains to be seen how widely GaN power
transistors will be adopted. Will GaN devices eventually
replace all Silicon power transistors? Or will there be peaceful
coexistence with complementary performance? Where will
GaN succeed and where will Silicon still thrive? This
presentation will attempt to answer these questions by
considering historical precedence, by considering relative
strengths and weaknesses of each technology, by examining
initial applications for GaN devices, and by peering into the
crystal ball and projecting GaN vs Silicon adoption trends.
14.04.2016
Copyright © Infineon Technologies AG 2016. All rights reserved.
2
Outline
1
Historical Perspective for new power switch technology
2
GaN vs. Silicon Technology
3
First uses of GaN
4
Crystal gazing: where will silicon thrive and where will GaN
be adopted over time?
5
Concluding comments
14.04.2016
Copyright © Infineon Technologies AG 2016. All rights reserved.
3
Today‘s switch technology use by
power and frequency
Future scenario power electronics
Application
HVDC
HC-supplier
100M
Large drives
Ships
10M
Locomotives
Large solar plants
1M
Trams, buses
Electric cars
100k
On-roof PV
Small drives
10k
Air conditioner
Robotics
1k
Washing machine
› SMPS
› Chargers/Adapters
100
10
10
Power by application (W)
ULTRA HIGH POWER
HIGH POWER
Thyristor
›
›
›
›
›
›
›
›
›
›
›
›
›
1G
Starting with Bipolar Junction
Transistors (BJT), new
technologies pushed out the
(frequency and density)
performance window.
IGBT
Higher Power
1a
BJT
100
MID POWER
LOW POWER
Reduced size
MOSFET
1k
10k
100k
Degree of adoption depends strongly on cost
14.04.2016
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1M
10M
100M
Frequency (Hz)
4
1b
Historical perspective: “conversion” from power
bipolar transistor to power MOSFET
Power Transistor Market Size ($M)
Technology
1984 (HTE,
1991)
2015(IHS)
Bipolar Junction Transistor
MOSFET
Superjunction MOSFET
IGBT
Total (Less SJ MOSFET)
$957
$115
$0
$0
$1,072
$881
$6,034
$895
$4,946
$11,861
›
›
›
After 30 years of “conversion” the bipolar market is basically unchanged in
size (not accounting for inflation)
New power transistor technologies nibbled at the edge of predecessor
technologies but basically established new markets enabled by higher
performance (frequency, power)
Incumbent technologies are not easily “replaced”; rather a new technology
is adopted in new designs and new applications where it offers higher
overall efficiency , density or cost benefits (which vary greatly by market
segment)
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5
2a
Technology comparison: GaN vs Silicon*
E-mode
GaN
Equivalent
Super
junction
FET
Vdss
600 V
600 V
RDSon typ 25°C
52 mΩ
52 mΩ
Parameter
Comments
Eoss
7 uJ
8 uJ
Near parity for
hard switching
performance
Tk,RDS(on) (150°C/25°C)
1.8
2.37
RDS(on) Tempco
6 nC
68 nC
1 nC
6,000 nC
GaN >100X lower than
SJ (including Qoss)
110 pF
1,050 pF
GaN ~10x lower
1.0
0.77
Qg (10 V Vgs, 400 V Vds)
Qrr (100 A/µs, 25°C)
Co(tr) (400 V)
Rθ J-C (°C/W)
(Qoss: 44 nC)
GaN >10x lower than
Superjunction FET
Consistent with package
* GaN values are for prototype devices
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6
Superjunction vs GaN: why no large
difference is seen in hard switching losses
2b
Blue = superjunction
Red = e-mode HEMT
Both ~70 mΩ max RDS(on)
›
›
Superjunction capacitances are much
higher when compared to GaN
Superjunction Coss and Crss behave very
nonlinearly with voltage
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›
›
Output charge difference is very large (up
to 10x at 100 V) between superjunction
and GaN
But gap in Eoss is much smaller (eg: 20% at
400 V)
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7
Nonlinear Qoss charge affects deadtime
2c
500
450
-SJ FET has 3.3X
longer charge-up time
400
350
Volts
300
250
200
150
Qoss Measurement Circuit
100
50
0
0
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10
20
30
40
50
60
70
80
Time (µs)
90
100
Copyright © Infineon Technologies AG 2016. All rights reserved.
110
120
130
140
150
8
2d
Non linearity of Coss results in longer
minimum dead time for SJ FET in ZVS
CoolMOS™ P6
Cascode GaN
110 nSec
Vgs_ls
50V
Vds_ls
Tdelay
Id_ls
 Vgs=10 V, Id=2 A, Rg=10 ohm
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20 nSec
SJ FET High capacitance at low voltage results
in 5-6x longer delay time (110 nsec vs 20
nsec)and therefore longer required deadtime
which increases RMS current and therefore
conduction losses. The higher the frequency
the more the losses
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9
2e
Superjunction devices continue to improve
Reference: G. DeBoy, PCIM 2015
Yet the more the improvement in hard switching figure
of merit the longer the delay times (limits performance
in ZVS applications at higher frequency)
14.04.2016
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2f
Significant efficiency gains in superjunction –
C7 600 V with ≥0,5% improvement across load
PFC efficiency difference for 90 Vac (PFC CCM, 1150 W @ 65 kHz)
Efficiency Low Line
97
Superjunction
FET performance
continues to
improve in hard
switching PFC
applications
eta [%]
96
95
0,5%
0,6%
IPW60R045CP
IPP60R040C7
IPZ60R040C7
fps@IFX
94
0
200
400
600
800
1000
1200
≥ 0,5% efficiency
increase across
entire load range
with CoolMOSTM
C7 4-pin vs. CP
1400
Pout [W]
14.04.2016
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11
Benefits of C7 CoolMOSTM enables operation
at higher (hard) switching frequencies
2g
Total simulated MOSFET losses [W]
IPW60R045CP vs IPZ60R060C7, highline 2.5 kW
Gate charge
Turn off
Turn on
Conduction
CP
18,3
0,4
12,4
0,2
8,7
0,2
2.3
6.0
7,1
0,1
3.0
4,7
0.1
0.8
6,6
0,1
1.5
4.1
2.1
6.3
1,0
1.9
2.8
2.1
2.9
2.3
3.0
CP
C7
CP
C7
CP
C7
130 kHz
C7
3.2
2.1
65 kHz
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9.3
> Smaller MOSFET
losses for C7 @
130 kHz than CP
@ 65 kHz
> Increasing
relative
advantage of C7
with growing
frequencies
C7 opens a path to
higher frequencies
in proven silicon
technology
200 kHz
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12
2h
Technology comparison summary
› Superjunction Coss and Crss behave very nonlinearly with voltage and
frequency
› Comparable RDS(on) GaN devices have much lower capacitance than
their SJ FET counterparts when measured at low voltage; this
difference greatly diminishes at higher voltages; there is not a large
difference in Eoss at 400 V
› Co(tr) of GaN device is ~10x lower than SJ FET and this
difference is sustainable; this benefit can be leveraged in ZVS
applications where it can result in lower power losses
› This benefit grows with frequency (as a fixed deadtime grows in
percentage of total switching cycle time)
› Qrr >100x lower for GaN devices: this can be leveraged in choice
of topology and application
14.04.2016
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3a
First uses for GaN
› Initial Applications for GaN Devices:
› Leverage Qrr: Class D Audio Amplification for lowest distortion
› Leverage Qrr and switching: high efficiency AC:DC power
conversion for operational cost sensitive applications such as
datacenters
› Leverage Co(tr): high density power conversion applications from
servers to consumer electronics
› The list above is just the start! The study of other applications (to
leverage GaN FOM’s vs Silicon) is an ongoing effort
14.04.2016
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14
3b
First use of GaN: 100 V cascode
device for class D audio amplifier
Leverages extremely
low Qrr
Key values
GaN benefit vs Silicon
Audio Quality
Lower - THD improves from
faster/cleaner switching characteristics
Efficiency
Higher - from lower resistance
More
channels,
smaller size
Smaller – Full SMD w/o heatsink, high
frequency for smaller LPF
Fast switching
GaN
Si FET
14.04.2016
MP: 2013
Copyright © Infineon Technologies AG 2016. All rights reserved.
15
3c
First Uses of GaN:
GaN value proposition for data centers
Effect of higher efficiency on electricity costs
› Total Cost of Ownership (TCO)
matters: hardware/software +
operational costs really matters
› Electricity costs is ranked in TOP 5
costs
› Efficiency of electricity usage can lead
to significant system cost savings
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Stage
Efficiency
increase
Savings per
server per year
PFC
0.5%
4.5$
DCDC
(LLC)
0.5%
4.5$
Total
1.0%
9.0$
Based on energy cost: 0.06USD/kWh, 1.5kW average
power consumption per server, 80% yearly utilization
Copyright © Infineon Technologies AG 2016. All rights reserved.
16
3d
High Power SMPS in datacenters:
Evolution of high efficiency topologies for PFC
Classic
HB TotemPole
TODAY´S BEST
Dual Boost
Higher efficiency (>98%)
›
TOMORROW´S BEST
TODAY/
TOMORROW
TCM PFC
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›
Highest efficiency (>98%)
›
Simpler
›
Reduced part cont
FB TotemPole
›
Higher efficiency (99%)
›
2-phases (high part count)
›
Complex control
›
100 kHz+ operation
›
Higher efficiency (>99%)
TCM PFC w/ GaN
›
Highest efficiency (99.5%)
›
Suitable for 1 MHz+ operation
›
Coupled with HF LLC for
extreme power density
(>>100 W/in3)
Copyright © Infineon Technologies AG 2016. All rights reserved.
Targeting 99% A-Z
17
3e
GaN enables >99% PFC efficiency
>99% efficiency
from 18-70% load
45kHz
Leverages:
extremely low Qrr
65kHz
› Measurements: Infineon 2015
› Complete Power Stage. 2.5 kW, Vin=230 V,
Tamb=25° C
› Full SMD solution
14.04.2016
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18
1. 600 V CoolGaN™ for density: 3 kW LLC
PD~140 W/in3
SJ based 130 kHz design
GaN based 350 kHz design
H=42 mm
W=91 mm
H=32 mm
140W/in3
L=220 mm
L=152 mm
50W/in3
W=140 mm
KEY MESSAGES
› LLC w/ CoolMOS™ (380 V-54.3 V): >98% peak
efficiency at 50 W/in3 density (res freq: 130 kHz)
› LLC w/ CoolGaN™ (380 V-52 V): same efficiency at
140 W/in3 density (res freq: 350 kHz)
› GaN enables ~3x increase in power density.
When size/weight matters GaN is the choice
Same efficiency
› All this is achievable with full SMD solution,
either with DSO-20 or TOLL
› Similar results have been demonstrated for low power
and different ZVS topologies (e.g. PSFB)
14.04.2016
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19
CoolGaN™ enables dramatic increase in
power conversion density using ZVS in LLC
3g
Practical Frequency limit of
Superjunction FET’s in LLC
450
Density (W/in3)
350
Today’s
Today’s GaN
Superjunction HEMT FET based
FET based
designs
designs
250
Tomorrow?
9-10x
improvement
over SJ FET
(Work of CPES,
Virginia Tech
University)
150
3x Improvement
over SJ FET
(Infineon Work)
50
150
14.04.2016
350
Frequency (kHz)
Copyright © Infineon Technologies AG 2016. All rights reserved.
1000
20
In which power and frequency
domain might GaN be used?
Future Scenario Power Electronics
Application
›
›
›
›
›
›
›
›
›
›
›
›
›
1G
HVDC
HC-supplier
100M
Large drives
Ships
10M
Locomotives
Large solar plants
1M
Trams, buses
Electric cars
100k
On-roof PV
Small drives
10k
Air conditioner
Robotics
1k
Washing machine
› SMPS
› Chargers/Adapters
100
10
10
Power by application (W)
ULTRA HIGH POWER
HIGH POWER
Thyristor
4
IGBT
SiC
MID POWER
GaN
LOW POWER
BJT
100
MOSFET
1k
10k
100k
Reduced size
1M
Degree of adoption depends strongly on Cost
14.04.2016
Copyright © Infineon Technologies AG 2016. All rights reserved.
10M
100M
Frequency (Hz)
21
5
Concluding comments
›
The historical record shows new switch technologies are adopted and grow new
market segments where they push the performance window
›
KEY GaN device FOM‘s are demonstrated with 10-100x improvement over
silicon (Coss TR, Qrr)
› It is clear this can be leveraged for higher density power conversion
solutions using ZVS and LLC topology
› Early applications identified but more will follow as cost of GaN device
lowers and investment continues in new topology and application
infrastructure
›
LV and HV MOSFET‘s continue with fast pace of improvement in market
segments that are still growing: Silicon is not at the end of the road!
› Silicon Market size not shrinking any time soon
›
Ultimately the size of new market segments which adopt GaN will
depend strongly on system cost
14.04.2016
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