Achieving highefficiency design with Infineon CoolMOSTM and OptiMOSTM

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Achieving high-efficiency designwithInfineon
CoolMOSTM and OptiMOSTM
Power Technology Conference

• Materials re-organized by Jerome Lee

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New efficiency requirement in ATX silver box

• Climate Saver Computing Initiative (CSCI)
  announce new initiative Platinum Standard.
  Targeting 90 94 and 92 efficiency at 20 50
  and 100 loading respectively.
• New topology is blooming with better control
  scheme. In which semi-conductor compensate the
  limitation of the topology.

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Typical Solution for multi-output SMPSCross
Regulation Cost competitive but higher loss
Main Stage DC/DC Two transistor Forward
Mag Amp
PFC Pre-regulation CCM Boost
Auxilliary Converter FF Flyback
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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge primary
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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Losses Analysis (Overall System) Various AC
inputLosses break down (eg. 300W system with
three output)
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Losses Analysis (20 Load) - EMILosses break
down (eg. 300W system with three output)

• Low line / light load situation

Total 0.64W
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Losses Analysis (20 Load) - PFCLosses break
down (eg. 300W system with three output)

• Low line / light load situation

Total 5.44W
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Losses Analysis (20 Load) - DC/DCLosses break
down (eg. 300W system with three output)

• Low line / light load situation

??
Total 8.44W
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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge
  configuration
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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Synchronous RectificationWhat is a synchronous
rectifier?
diode

MOSFET

• a MOSFET (sync. FET) replaces a diode in its
  electrical functionality
• the sync. FET has NO control function ? no
  active switching of current ? (gate) switching
  speed has no influence on efficiency!
• no additional function compared to the diode is
  realized
• with a gate-source short on the sync. FET, the
  system stays electrically functionable

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Disassembling a MOSFETelectrical symbol with
parasitics?
ideal switch
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Synchronous Rectificationcommutation loop
example current doubler
freewheel
forward
L
OUT
1
High side switch
C
OUT
Transformer
GND
Low side switch
L
OUT
2
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Synchronous RectificationPower loss distribution

• 80V MOSFET technology transformer output 40V
  Vout 12V

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Synchronous Rectificationbrief summary II

• Conducting losses
• Body diode conduction loss
• Gate losses
• Turn-off reverse recovery losses

Conduction
Switching
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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge primary
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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Disassembling a MOSFETpackage contribution to
total Rds(on)
package contribution to Rds(on) for best in class
devices
high package contribution, Si technology is
hindered by package


D²-Pak7pin
CanPAK M
CanPAK S
S3O8
TO-220
SuperSO8
D²-Pak
without layout contribution
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Synchronous RectificationLosses must be balanced!
Losses for a given output power and switching
frequency!
power losses W
3
capacitive losses dominate
balanced operation
2.5
2
conduction losses dominate
1.5
1
.5
0
0
5
10
15
20
25
Resistance mOhm
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Selection SR
RMS currentn Irms10A Target frequency
Fs100kHz Calculated voltage Vds40V Selection
BSC031N06N3 ?pcs
RMS Current
Switching frequency
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Choosing the right deviceFOM verification

• FOM Figure of merit (performance factor for a
  given MOSFET technology)
• The lower the FOM the better the technology
  (lower losses)

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Choosing the right deviceFOM_Qoss verification
transformer voltage
Example FOMQoss for a 80V technology at various
transformer voltages VT
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• Better FOMs for a given MOSFET technology by
• Reducing the maximum drain-source voltage
  (transformer voltage)
• Resulting in a lower Qoss gt lower power losses

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Choosing the right deviceFOM_Qoss verification
MOSFET voltage class
Example FOMQoss _at_ VT40V for a 40V, 60V, 80V and
100V technology
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• Better FOM by
• Lower voltage class technology

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Choosing the right deviceFOM_Qoss verification
MOSFET Rdson class
Example FOMQoss _at_ VT40V for a 80V technology in
different Rds(on)/package combinations

• The higher the Rdson class, the better the
  FOMQoss
• With SuperSO8 good FOMQoss value can be achieved
• Need for a compromise

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Choosing the right devicePackaging
through-hole or SMD?

• SuperSO8 achieves efficiency than TO-220 due to
• Much lower RDSon contribution of the package
• Lower output capacitance -gt lower switching
  losses
• No optimization of the snubber was done

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Synchronous RectificationConclusion for RC and
RCD snubber

• RCD snubber can boost efficiency up to 0.5
• No additional capacitance in parallel to the
  MOSFET is needed (lower reverse peak, lower
  losses)

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Choosing the right devicePackaging importance
of mounting

• The longer the connection length of the MOSFET
  the lower the efficiency, due to a higher
  resistance value

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Choosing the right devicePackaging importance
of mounting

• Longer electrical MOSFET connections mean
• Higher inductance
• Higher voltage stress for the MOSFET

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Choosing the right deviceComparison BiC devices
SuperSO8 (40V,60V,80V)

• Lower the voltage class ? better FOM_Coss ?higher
  efficiency

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LV-MOS and packagingsummary II
Source 0.2nH0.5mOhm
Drain (1cm) 8nH 0.55mOhm
Gate 0.5nH 35mOhm
Gate (1cm) 7nH 35mOhm
Drain 0nH 0mOhm
Source (1cm) 7nH0.55mOhm
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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge primary
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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OptiMOS3 Lowest Rds(on) for SR

• replacement parts for existing sockets
• new BiC devices in each voltage class from 30V to
  150V

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OptiMOS3 Fast switching for HS and LS
60V
80V
40V
Best FOM
200V
100V
150V
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General guideline for MOSFET package selection
high
Switching Frequency
SuperSO8
S3O8
CanPAK-S
CanPAK-M
medium
D2-PAK (TO262)
D-PAK (TO252)
TO-220
D2-PAK-7Pin
medium
high
Output Power
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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge primary
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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Roadmap of HV MOSFET

• Losses come from
• Rdson 60 conduction loss
• Delay in on/off (Qg..)30 switching loss
• (Dis)Charge Cds Cap. 10 Coss loss

G
S
30
n
p
10
gt90 of conductionlosses come from n-epih
n-epi
60
nsub

• To make it better
• Better conductivity ?Lower Rdson
• Faster switching ? lower Qg
• Lower capacitances?Lower Coss,etc

D
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Losses ReductionChoosing the right RDSon for
the PFC MOSFET

• CoolMOSTM has unique feature to accommodate both
  low Rdson (full load demand) as well as low
  capacitive (Light load demand)
• The usage of CoolMOSTM effectively balance the
  loss in both light load and full load situation.

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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge primary
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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What is soft switching?

• The drain source voltage reaches zero before the
  gate of the low side MOSFET turns on

Vmp
Pri Current
High Side Gate
Low Side Gate
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? C6 shows the best Figure-of-Merit RonEoss
and good FoM RonQoss
C6 behaviour in soft switching converters
150
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125
15
Good Qoss for C6
100
12
Qoss nC
Eoss µJ
75
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Best Eoss for C6
Qoss C6
50
6
Qoss C3
Qoss CP
Eoss C6
25
3
Eoss C3
Eoss CP
0
0
0
50
100
150
200
250
300
350
400
450
500
Voltage VDS V
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Hard commutation of body diode
Qrr C6 7.1µC trr C6 414ns
Qrr C3 9.6µC trr C3 510ns
IPP60R190C6
Qrr CFD 1.1µC trr CFD 155ns
? C6 shows less reverse recovery charge than C3
and better softness than CFD

• NO CFD-type required in applications with
  non-repetitive hard diode commutation such as
  LLC, phase shift ZVS etc.

C6 is the best choice for resonant topologies
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Efficiency difference for 99mOhm Parts in LLC
test circuit

• CP shows best efficiency
• C6 is very close to CP but in addition it offers
  excellent commutation ruggedness
• C6 can replace CP, C3 and CFD in resonant
  topologies

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Content

• Typical Solution of Silver Box and Losses
  Analysis
• Synchronous Rectification
• Energy Losses in synchronous with bridge primary
• Synchronous rectification MOSFET Selection
• Infineon OptiMOSTM for synchronous rectification
• Primary MOSFET
• Energy loss in hard switching system
• New CoolMOSTM C6 and Softswitching
• Higher efficiency with Infineon devices

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Infineon Approach for Silver Box Solution-
Topology and labeling
400V
AC in

• 12V
• 5V
• 3.3V

• 5V
• 3.3V

Voltage Regulation
N/A
Topology
PFC
DC/DC
Passive
Primary
Secondary
STF
Diode
CCM
TTF
Low Drop Schottky
Interleave Crit Mode
LLC
Sync Rec
Sync. Buck DC/DC
Active Clamp
Auxiliary / Standby Power
90 Plus
Fan Speed Controller
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Infineon Approach for Silver Box Solution-
Configuration
ICE1HS01G
IDT05S60C
BSC042N03LS G x 2 BSC042N03LS G x 2
ICE2PCS02 G
IPP037N06L3 G x 2
IPP60R190C6 x 2
IPP60R199CP
TDA21801
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Infineon Approach for Silver Box Solution-
90Plus Design Layout Compared with 80Plus Design
90Plus Design
80Plus Standard Design
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Superior Solutions from Superior Power
Semiconductors CoolMOS C6 600V Portfolio
TO-252 D-Pak D
TO-263 D²PAK B
TO-220 Fullpak A
TO-262 I²-PAK I
TO-220 P
TO-247 W
3.3 ? 1.8 A
IPD60R3k3C6
2 ? 2.5 A
IPD60R2k0C6
1.4 ? 3.2 A
IPP60R1k4C6
IPD60R1k4C6
0.95 ? 4.5 A
IPA60R950C6
IPP60R950C6
IPB60R950C6
IPD60R950C6
0.75 ? 6.2 A
IPP60R750C6
IPD60R750C6
0.6 ? 7.3 A
IPA60R600C6
IPP60R600C6
IPB60R600C6
IPD60R600C6
0.52 ? 8 A
IPA60R520C6
IPP60R520C6
IPD60R520C6
0.45 ? 9.5 A
IPA60R450C6
IPP60R450C6
IPD60R450C6
0.38 ? 11 A
IPA60R380C6
IPP60R380C6
IPB60R380C6
IPD60R380C6
IPI60R380C6
0.28 ? 15 A
IPA60R280C6
IPP60R280C6
IPB60R280C6
IPW60R280C6
IPI60R280C6
0.19 ? 20 A
IPA60R190C6
IPP60R190C6
IPB60R190C6
IPW60R190C6
IPI60R190C6
0.16 ? 24 A
IPA60R160C6
IPP60R160C6
IPB60R160C6
IPW60R160C6
0.125 ? 30 A
IPW60R125C6
IPP60R125C6
IPA60R125C6
0.099 ? 35 A
IPW60R099C6
IPP60R099C6
IPA60R099C6
IPB60R099C6
0.07 ? 47 A
IPW60R070C6
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OptiMOS Product Information

• Please visit for the latest OptiMOSTM technology

http//www.infineon.com/OptiMOS
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Reference

• Deboy Gerald, Fanny Bjoerk, Jon Hancock,
  Application NoteCoolMOSTM CP- How to make most
  beneficial use of the latest generation of super
  junction technology devices.
• Lutz Görgens, Maximizing the Effect of Modern
  Low Voltage Power MOSFETs, APEC 2009.
• Juan Sanchez, Extracted from various application
  presentation example, 2009
• Moesslacher Christian, Extracted from various
  application presentation example, 2009.
• Matteo-Alessandro Kutschak, 90Plus Project.
• Christian Jeschko, Matteo Kutschak, 600V
  CoolMOS C6

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