SiC Power Devices and Modules Application Note

SiC Power Devices and Modules
Application Note
Rev.001
Issue of June 2013
13103EAY01
Contents
1. SiC Semiconductors .............................................................................................................................................. 3
1.1 Property of SiC material .......................................................................................................................... 3
1.2 Advantages of SiC material for power device applications......................................................... 3
2. Characteristics of SiC Schottky Barrier Diode (SBD) .............................................................................. 5
2.1 Device structure and characteristics .................................................................................................... 5
2.2 Forward characteristics of SiC-SBD ................................................................................................... 5
2.3 Reverse recovery characteristics of SiC-SBD.................................................................................. 6
3. Characteristics of SiC-MOSFET ...................................................................................................................... 8
3.1 Device structure and characteristics .................................................................................................... 8
3.2 Specific on-resistance ............................................................................................................................... 9
3.3 Vd-Id characteristics .............................................................................................................................. 10
3.4 Gate voltage Vgs to drive SiC-MOSFET and Rdson ................................................................. 10
3.5 Vg-Id characteristics .............................................................................................................................. 11
3.6 Turn-on characteristics.......................................................................................................................... 12
3.7 Turn-off characteristics ......................................................................................................................... 13
3.8 Internal gate resistance.......................................................................................................................... 14
3.9 Gate drive circuit .................................................................................................................................... 15
3.10
Forward characteristics of body diode and reverse conduction .......................................... 15
3.11
Reverse recovery characteristics of body diode ....................................................................... 17
4. Characteristics of SiC power modules ......................................................................................................... 18
4.1 Characteristics of SiC power module............................................................................................... 18
4.2 Topologies................................................................................................................................................. 18
4.3 Switching characteristics ...................................................................................................................... 19
4.3.1 Id and Tj dependencies of switching characteristics .......................................................... 19
4.3.2 Gate resistance dependency of switching characteristics ................................................. 20
4.3.3 Gate voltage dependency of switching characteristics ...................................................... 21
4.4 Comparison of switching loss with Si-IGBT power modules ................................................. 22
4.4.1 Comparison of total switching loss with Si-IGBT power modules ............................... 22
4.4.2 Comparison of diode reverse recovery loss (Err) with Si-IGBT power modules .... 22
4.4.3 Comparison of turn-on loss (Eon) with Si-IGBT ................................................................ 23
4.4.4 Comparison of turn-off loss (Eoff) with Si-IGBT power modules ............................... 24
5. Reliability of SiC-SBD ..................................................................................................................................... 25
5.1 dV/dt and dI/dt break-down ................................................................................................................ 25
5.2 Results of SiC-SBD reliability tests ................................................................................................. 25
6. Reliability of SiC-MOSFET............................................................................................................................ 26
6.1 Reliability of gate insulating layer .................................................................................................... 26
1
6.2 Stability of gate threshold voltage against positive gate voltage ............................................ 27
6.3 Stability of gate threshold voltage against negative gate voltage ........................................... 27
6.4 Reliability of body diodes .................................................................................................................... 28
6.5 Short circuit safe operation area ........................................................................................................ 29
6.6 dV/dt breakdown..................................................................................................................................... 30
6.7 Neutron-induced single event burnout ............................................................................................ 30
6.8 Electrostatic discharge withstand capability.................................................................................. 30
6.9 Results of SiC-MOSFET reliability tests ....................................................................................... 31
7. Instructions to use SiC power modules and their reliability ................................................................. 32
7.1 Measures to reduce surge voltage ..................................................................................................... 32
7.2 Bridge arm short circuit by self turn-on .......................................................................................... 32
7.3 RBSOA (Reverse bias safe operating area) ................................................................................... 33
7.4 Results of SiC power module reliability tests ............................................................................... 34
8. Definition of part number................................................................................................................................. 35
8.1 SiC-SBD (discrete components) ........................................................................................................ 35
8.2 SiC-MOSFET (discrete components) .............................................................................................. 35
8.3 SiC Power Modules ............................................................................................................................... 36
8.4 SiC-SBD (bare dice) .............................................................................................................................. 36
8.5 SiC-MOSFET (bare dice) .................................................................................................................... 36
9. Examples of applications and benefits of using SiC ............................................................................... 37
9.1 Power factor correction (PFC) circuits (CCM - Continuous conduction mode) ............... 37
9.2 Solar inverters .......................................................................................................................................... 37
9.3 DC/DC converters .................................................................................................................................. 37
9.4 Bi-directional converters ...................................................................................................................... 38
9.5 Inverters for induction heating equipment ..................................................................................... 38
9.6 Motor drive inverters ............................................................................................................................. 38
9.7 Buck converters ....................................................................................................................................... 39
2
1. SiC Semiconductors
1.1
Property of SiC material
SiC (Silicon Carbide) is a compound semiconductor comprised of silicon (Si) and carbon (C). Compared
to Si, SiC has ten times the dielectric breakdown field strength, three times the bandgap, and three times
the thermal conductivity. Both p-type and n-type regions, which are necessary to fashion device structures
in a semiconductor materials, can be formed in SiC. These properties make SiC an attractive material
from which to manufacture power devices that can far exceed the performance of their Si counterparts.
SiC devices can withstand higher breakdown voltage, have lower resistivity, and can operate at higher
temperature.
SiC exists in a variety of polymorphic crystalline structures called polytypes e.g., 3C-SiC, 6H-SiC,
4H-SiC. Presently 4H-SiC is generally preferred in practical power device manufacturing. Single-crystal
4H-SiC wafers of 3 inches to 6 inches in diameter are commercially available.
Properties
Crystal Structure
Energy Gap : E G (eV)
Si
Diamond
1.12
Electron Mobility : μn (cm2/Vs)
2
Hole Mobility : μp (cm /Vs)
6
Breakdown Field : E B (V/cm) X10
Thermal Conductivity (W/cm℃)
Saturation Drift Velocity : v s (cm/s) X107
Relative Dielectric Constamt : εS
p, n Control
Thermal Oxide
4H-SiC
GaAs
Hexagonal Zincblende
3.26
1.43
GaN
Hexagonal
3.5
1400
900
8500
1250
600
100
400
200
0.3
1.5
1
11.8
○
○
3
4.9
2.7
9.7
○
○
0.4
0.5
2
12.8
○
×
3
1.3
2.7
9.5
△
×
Table 1
1.2
Advantages of SiC material for power device applications
With dielectric breakdown field strength approximately 10 times higher than that of Si. SiC devices can
be made to have much thinner drift layer and/or higher doping concentration, i.e., they have very high
breakdown voltage (600V and up) and yet with very low resistance relative to silicon devices. Resistance
of high-voltage devices is predominantly determined by the width of the drift region. In theory, SiC can
reduce the resistance per unit area of the drift layer to 1/300 compared to Si at the same breakdown
voltage.
The most popular silicon power devices for high-voltage, high-current applications are IGBT (Insulated
Gate Bipolar Transistors). With IGBTs , low resistance at high breakdown voltage is achieved at the cost
of switching performance. Minority carriers are injected into the drift region to reduce conduction (on-)
resistance. When the transistor is turned off, it takes time for these carrier recombine and “dissipate”, thus
increasing switching loss and time. In contrast, MOSFETs are majority carrier devices. Taking
3
advantages of SiC’s higher breakdown field and higher carrier concentration, SiC MOSFET thus can
combine all three desirable characteristics of power switch, i.e., high voltage, low on-resistance, and fast
switching speed.
The larger bandgap also means SiC devices can operate at higher temperatures. The guaranteed operating
temperature of current SiC devices is from 150C - 175C. This is due mainly to thermal reliability of
packages. When properly packaged, they can operate at 200C and higher.
4
2. Characteristics of SiC Schottky Barrier Diode (SBD)
2.1
Device structure and characteristics
SiC SBDs (Schottky barrier diodes) with breakdown voltage from 600V (which far exceeds the upper
limit for silicon SBDs) and up are readily available. Compared to silicon FRDs (fast recovery diodes),
SiC SBDs have much lower reverse recovery current and recovery time, hence dramatically lower
recovery loss and noise emission. Furthermore, unlike silicon FRDs, these characteristics do not change
significantly over current and operating temperature ranges. SiC SBDs allow system designers to improve
efficiency, lower cost and size of heat sink, increase switching frequency to reduce size of magnetics and
its cost, etc.
SiC-SBDs are increasingly applied to circuits such as power factor correctors (PFC) and secondary side
bridge rectifier in switching mode power supplies. Today’s applications are air conditioners, solar power
conditioners, EV chargers, industrial equipment and so on.
ROHM’s current SiC SBD lineup includes 600V and 1,200V; amperage rating ranges from 5A to 40A.
1,700V devices are under development.
Voltage
PND
6.5kV
Minority carrier device: Smaller resistance
but slow switching
3.3kV
PND, FRD
Majority carrier device: Fast switching
1.7kV
- Huge
reduction in
recovery loss
- Downsizing of
passive filter
components
1.2kV
900V
600V
SBD
400V
100V
SBD
Si
Achievable but
smaller merit
SiC
Figure 1
2.2
Forward characteristics of SiC-SBD
SiC-SBDs have similar threshold voltage as Si-FRDs, i.e., a little less than 1V. Threshold voltage is
determined by Schottky barrier height. Normally, a low barrier height corresponds with low threshold
voltage and high reverse leakage current. In its second-generation SBDs, Rohm has improved the
5
process to reduce threshold voltage by about 0.15V while maintaining the leakage current and recovery
performance. Unlike Si-FRDs, Vf increases with temperature. SiC SBDs have positive temperature
coefficient and thus will not cause thermal runaway when used in parallel.
Forward Characteristics of 600V 10A SiC-SBD
10
G1
G2
G1
G2
9
Forward Current: If [A]
8
7
SBD
SBD
SBD
SBD
25℃
25℃
125℃
125℃
6
5
4
3
2
1
0
0
0.5
1
1.5
Forward Voltage: Vf [V]
2
Figure 2
2.3
Reverse recovery characteristics of SiC-SBD
Si fast P-N junction diodes (e.g. FRDs: fast recovery diodes) have high transient current at the moment
the junction voltage switches from the forward to the reverse direction, resulting in significant switching
loss. This is due to minority carriers stored in the drift layer during conduction phase when forward
voltage is applied. The higher the forward current (or temperature), the longer the recovery time and the
larger the recovery current.
In contrast, since SiC-SBDs are majority carrier (unipolar) devices that use no minority carriers for
electrical conduction, they do not store minority carriers. The reverse recovery current in SiC SBDs is
only to discharge junction capacitance. Thus the switching loss is substantially lower compared to that in
Si-FRDs. The transient current is nearly independent of temperatures and forward currents, and thereby
achieves stable fast recovery in any environment. This also means SiC-SBDs generate less noise from the
recovery current.
6
Reverse Recovery Waveform (600V 10A)
Temperature Dependency
Si-FRD
SiC-SBD
15
10
Vr=400V
10
5
Forward Current: If (A)
Forward Current: If (A)
15
Vr=400V
0
-5
-10
-15
-20
Si-FRD (RT)
-25
Si-FRD (125℃)
-30
5
0
-5
-10
-15
-20
SiC-SBD (RT)
-25
SiC-SBD (125℃)
-30
0
100
200
300
Time (nsec)
400
500
0
100
200
300
Time (nsec)
400
500
Figure 3
Forward Current Dependency
Si-FRD
SiC-SBD
30
30
Forward Current: If (A)
Forward Current: If (A)
20
Vr=400V
o
Ta=25 C
If=20A
Vr=400V
o
Ta=25 C
If=20A
If=10A
10
If=2.5A
0
-10
-20
20
If=10A
10
If=2.5A
0
-10
-20
-30
-30
0
100
200
300
Time (nsec)
400
500
0
100
200
300
Time (nsec)
400
500
Figure 4
7
3. Characteristics of SiC-MOSFET
3.1
Device structure and characteristics
Si power devices with higher breakdown voltages have considerably high on-resistance per unit area,
which increases approximately by the 2nd to 2.5th power of the breakdown voltage. As a result, IGBTs
(Insulated Gate Bipolar Transistors) have been mainly used in devices with breakdown voltages of 600V
or higher. IGBTs achieve lower on-resistance than MOSFETs by injecting minority carriers into the drift
region, a phenomenon called conductivity modulation.
These minority carriers generate tail current
when transistors are turned off, resulting in a significant switching loss.
SiC devices do not need conductivity modulation to achieve low on-resistance since they have much
lower drift-layer resistance than Si devices. MOSFETs generate no tail current in principle. As a result,
SiC MOSFETs have much lower switching loss than IGBTs, which enables higher switching frequency,
smaller passives, smaller and less expensive cooling system. Compared to 600V-900V silicon MOSFETs,
SiC MOSFETs have smaller chip area (mountable on a compact package) and an ultralow recovery loss
of body diodes. For these reasons, SiC-MOSFETs are increasingly being used in power supplies for
industrial equipments and inverters/converters for high-efficiency power conditioners.
.
ROHM’s current lineup includes 650V and 1,200V planar type MOSFETs. 1,700V MOSFETs are under
development.
Voltage
IGBT
6.5kV
3.3kV
Minority carrier device: Smaller resistance
but slow switching
IGBT
- Huge reduction
in turn-off loss
- Downsizing of
passive filter
components
1.7kV
1.2kV
Majority carrier device: Fast switching
MOSFET
900V
- Die size reduction
- Reduced body Di
reverse recovery
600V
400V
100V
SJ-MOSFET
MOSFET
Si
Achievable but
smaller merit
SiC
Figure 5
8
3.2
Specific on-resistance
Since SiC has dielectric breakdown field strength 10 times higher than that of Si, high breakdown voltage
devices can be achieved with a thin drift layer with high doping concentration. This means, at the same
breakdown voltage, SiC devices have quite low specific on-resistance (on-resistance per unit area). For
example, 900V SiC-MOSFET can provide the same on-resistance as Si-MOSFETs and Si super junction
MOSFETs with a chip size 35 times and 10 times respectively smaller. Smaller chip size reduces gate
charge Qg and capacitance.
Existing Si super junction MOSFETs are only available for breakdown voltages up to around 900V.
Area specific resistance RonA (mΩcm2)
SiC-MOSFETs have breakdown voltages up to 1,700V or higher with low on-resistance.
400
350
Si-MOSFET
300
250
200
150
Si-Super-Junction
100
50
SiC-DMOSFET
0
500
700
900
1100
1300
1500
1700
Blocking Voltage (V)
Figure 6
9
3.3
Vd-Id characteristics
Since SiC-MOSFETs have no threshold voltage (knee) as IGBTs, they have a low conduction loss over
wide current range.
Si-MOSFETs’ on-resistance at 150C is more than twice that at room temperature, whereas
SiC-MOSFETs’ on-resistance increases only at a relatively low rate. This facilitates thermal design for
SiC-MOSFETs and provides low on-resistance at high temperatures.
Vds - Id (Ta=25˚C)
Vds - Id (Ta=150˚C)
30
30
ROHM
SiC MOSFET
1200V
Si SJMOS
900V
25
Drain Current: Id (A)
Drain Current: Id (A)
25
20
15
10
Si IGBT
1200V
5
Si IGBT
1200V
Si SJMOS
900V
20
ROHM
SiC MOSFET
1200V
15
10
ROHM (Vgs=18V)
ROHM (Vgs=18V)
5
SJ MOS (Vgs=10V)
SJ MOS (Vgs=10V)
IGBT (Vgs=15V)
IGBT (Vgs=15V)
0
0
0
1
2
3
4
0
5
1
2
3
4
5
Drain-Source Voltage: Vds (V)
Drain-Source Voltage: Vds (V)
Figure 7
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
3.4
Gate voltage Vgs to drive SiC-MOSFET and Rdson
Although SiC-MOSFETs have lower drift layer resistance than Si-MOSFETs, the lower carrier mobility
in SiC means their channel resistance is higher. For this reason, the higher the gate voltage, the lower the
on-resistance. Resistance becomes progressively saturated as Vgs gets higher than 20V. SiC-MOSFETs
do not exhibit low on-resistance with the gate voltage Vgs of 10 to 15V which is applied to typical IGBTs
and Si-MOSFETs. It is recommended to drive SiC-MOFETs with Vgs set to 18V in order to obtain
adequately low on-resistance.
Please be advised not to use SiC-MOSFETs with Vgs below 13V as doing so may cause thermal
runaway.
10
On-resistance vs Vgs
Vgs-Rdson Id=10A
Rdson(mΩ)
300
25℃
50℃
75℃
100℃
125℃
150℃
200
100
0
5
10
15
20
25
Vgs (V)
Figure 8
3.5
Vg-Id characteristics
The threshold voltage of SiC-MOSFET is about the same as Si-MOSFET’s, i.e., approximately 3V at
room temperature (normally OFF) at a few mA. However, since approximately 8V or more of gate
voltage is required to conduct several amperes of current, SiC-MOSFET can be said to have higher noise
immunity than IGBT to accidental turn-on. The threshold voltage decreases with increasing temperature.
Vg- Id Characteristics (linear scale)
Vg- Id Characteristics (log scale)
30
VDS = 10V
Pulsed
10
Ta=
Ta=
Ta=
Ta=
1
V DS = 10V
Pulsed
25
Drain Current : ID [A]
Drain Current : ID [A]
100
150ºC
75ºC
25ºC
-25ºC
0.1
20
Ta=
Ta=
Ta=
Ta=
15
10
150ºC
75ºC
25ºC
-25ºC
5
0.01
0
0
2
4
6
8 10 12 14 16 18 20
Gate - Source Voltage : VGS [V]
0
2
4
6
8
10 12 14 16 18 20
Gate - Source Voltage : VGS [V]
Figure 9
11
3.6
Turn-on characteristics
The double-pulse clamped inductive load test setup below is used to compare switching performance of
two half-bridge circuits. One half bridge uses Rohm’s SCH2080KE SiC-MOSFET co-packaged with
SiC-SBD; the other uses a Si-IGBT co-packaged with Si-FRD.
Same type
device as D.U.T.
200uH
400V
200uF
D.U.T.
Figure 10
The turn-on switching rate of SiC-MOSFET is several tens of nanoseconds, which is equivalent to that of
Si-IGBT and Si-MOSFET. However, inductive load switching causes a recovery current from
commutation to the upper arm diodes to pass through the lower arm.
Si-FRDs and Si-MOSFET body diodes normally have exceedingly high recovery current, resulting in
heavy losses. Furthermore, these losses tend to worsen at high temperature. In contrast, SiC-SBDs have
low recovery current and short recovery time which are fairly independent of temperature.
SiC-MOSFET’s body diode has recovery performance equivalent to that of discrete SiC-SBDs, but it has
higher Vf. This fast recovery performance of diodes reduces turn on loss (Eon) by several tens of
percentages.
The switching rate depends largely on the external gate resistance Rg. For fast switching, it is
recommended to use a small gate resistor of several ohms. The selection of appropriate gate resistance
must take surge voltage into account.
12
SiC-MOSFET+SBD
Si-IGBT+FRD
(SCH2080KE)
100ns
100ns
Vgs(5V/div)
Vge (5V/div)
Ic (5A/div)
Id (5A/div)
Eon=498.4uJ
*includes diode recovery loss
Eon=331uJ
*includes diode recovery loss
Vds (100V/div)
Vce (100V/div)
Figure 11
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
3.7
Turn-off characteristics
The most distinctive feature of SiC-MOSFETs is that they do not exhibit tail currents as observed in
IGBTs. Therefore SiC MOSFETs can have turn off loss (Eoff) that is approximately 90% smaller.
IGBT’s tail current increases with temperature whereas switching characteristics of MOSFETs are nearly
independent of temperature. IGBT’s high switching loss increases the chip’s junction temperature (Tj),
frequently limiting the switching frequency to 20 kHz or less. The much lower Eoff allows
SiC-MOSFETs to switch at much higher frequency, 50 kHz and higher. Size of passives and/or cooling
systems thus can be significantly reduced.
SiC-MOSFET+SBD
Si-IGBT+FRD
(SCH2080KE)
100ns
Vge (5V/div)
Ic (5A/div)
Vce (100V/div)
Vgs (5V/div)
Id (5A/div)
100ns
Vds (100V/div)
Eoff=890.2uJ
Eoff=109uJ
Figure 12
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
13
Downsizing of Passive Components (LC filters) by Increase of Switching Frequency
LC filter for 20kHz
LC filter for 50kHz
Figure 13
3.8
Internal gate resistance
The internal gate resistance is dependent on the sheet resistance of gate electrode material and chip size.
Other things being equal, the internal gate resistance is inversely proportional to the chip size - the
smaller the chip, the higher the gate resistance. At the same rating, SiC-MOSFET die is smaller than Si
die. Therefore, SiC-MOSFETs tend to have lower junction capacitances but higher gate resistance. As an
example, the internal gate resistance of Rohm’s 1,200V/80m SiC-MOSFET is approximately 6.3.
Switching time is dependent largely on the external gate resistance. In order to implement fast switching
operation, it is recommended to use low external gate resistor of several ohms while monitoring surge
conditions.
14
3.9
Gate drive circuit
SiC-MOSFETs are normally OFF voltage-controlled devices. Hence they are easy to drive and incur less
gate drive loss. The basic drive method is the same as that for IGBTs and Si-MOSFETs. The off-on gate
voltage swing is nominally 0 to 18V. If high noise tolerance and fast switching are required, negative
voltage of approximately 3 to 5V can also be used.
The following schematic shows connections to Rohm’s gate driver IC BM6103FV-C with supply
voltages of 18V and 4V. In order to drive a high-current element or a power module, it is
recommended to use a buffer circuit. For fast switching, it is recommended to use low external gate
resistor of several ohms.
22V
VCC2
ROHM
2SCR542
(30V,10Apk) Rg
(0～10Ω)
OUT1
e.g)
1.8kΩ
BM6103FV-C
10mA
GND2
VEE2
SiC MOSFET
ROHM
2SAR542
(30V,10Apk)
ROHM
TFZ3.9B
(3.9V)
0V
Figure 14
3.10
Forward characteristics of body diode and reverse conduction
Like Si-MOSFET, SiC-MOSFET contains a parasitic (body) diode formed in the P-N junction. However,
SiC MOSFET’s body diode has high threshold voltage (around 3V) and relatively large forward voltage
drop (Vf) due to the fact that the bandgap of SiC is 3 times larger than that of Si. When connecting an
external anti-parallel freewheeling diode to Si-MOSFET, an additional low-voltage blocking diode
needed to be connected to MOSFET in series to prevent the conduction through the “slow” body diode.
This is because Vf of the Si MOSFET’s body diode is about the same as that of the external diode. This
means more components and higher conduction loss. Such arrangement is not needed with SiC
MOSFETs since the Vf of their body diodes is sufficiently high compared to that of a typical external
free-wheeling diode.
The high Vf of the body diode can be reduced by turning on the gate voltage for reverse conducting like
synchronous rectification. Since in inverter drives the gate of the switching devices is often turned on in
the arm on the commutation side upon completion of dead time, commutation current is applied to the
15
body diode only during dead time. As a result, the high Vf of the body diode will not present problems
even if a bridge circuit is composed only of SiC-MOSFETs (without anti-parallel connected SiC-SBDs).
As described in Section 3.11, SiC MOSFETs’ body diodes have extremely fast recovery characteristics.
Source to Drain Current Path
Vgs=0V
Vgs=18V
Source (+)
Source (+)
Channel current
Body-Di current
Body-Di current
Drain (-)
Drain (-)
Figure 15
Vd- Id Characteristics (reverse direction)
0
Ta=25ºC
Pulsed
Drain Current : ID [A]
-5
-10
Vgs=0V
Vgs=2V
Vgs=4V
Vgs=6V
-15
-20
Vgs=10V
Vgs=14V
Vgs=18V
-25
-30
-10
-8
-6
-4
-2
0
Drain - Source Voltage : VDS [V]
Figure 16
16
3.11
Reverse recovery characteristics of body diode
The body diode of SiC-MOSFET is a P-N junction diode with short minority carrier lifetime. The
recovery current is mainly to discharge junction capacitance. Its recovery performance is equivalent to
that of a discrete SiC SBD. This enables a reduction in recovery loss to a fraction to a few to tens of
percents compared to a body diode of Si-MOSFET or Si-FRD used with IGBT as a freewheeling diode.
Like SBD, the recovery time of the body diode is independent of forward current If and fixed for a given
dI/dt. In inverter applications, SiC-MOSFET with or without anti-parallel SiC-SBD can achieve an
exceptionally-low recovery loss and can be expected to reduce noises due to very small reverse recovery
current.
25
SiC-MOSFET and SiC-SBD
SCH2080KE
SCT2080KE
20
SiC-MOSFET
If (A)
15
10
5
0
Vdd=400V
Ta=25℃
-5
0
50
100
150
200 250
time (ns)
300
350
400
Figure 17
17
4. Characteristics of SiC power modules
4.1
Characteristics of SiC power module
Currently, IGBT modules that combine Si-IGBTs and Si-FRDs are commonly used as power modules to
handle high currents and high blocking voltage. ROHM has pioneered commercial power modules
equipped with SiC-MOSFETs and SiC-SBDs. SiC modules allow substantial reduction in switching
losses associated with Si-IGBT’s tail current and Si-FRD’s recovery current. Among the benefits are:
･ Improvement of conversion efficiency thanks to lower switching losses
･ Simplification of thermal management, e.g., smaller and less expensive heat sink or cooling system,
replacement of water/forced air with natural cooling
･ Downsizing of passive components (inductors, capacitors) thanks to increasing switching frequency
SiC power modules are increasingly applied to power supplies for industrial equipments, PV power
conditioners and others.
4.2
Topologies
Rohm’s SiC power modules currently are available in half-bridge topologies and comprise either
SiC-MOSFETs only or SiC MOSFETs with anti-parallel SiC SBDs.
Photo of commercially available modules
3
4
17mm
2
46mm
122mm
1
Figure 18
18
Circuit Schematic of SiC Power Module (Half bridge Topology)
■SiC-MOSFET + SiC-SBD
■SiC-MOSFET
Figure 19
4.3
Switching characteristics
The switching characteristics of SiC power module are evaluated using the double-pulse clamped
inductive load test setup shown below. Parasitic inductance in the module is approximately 25nH, and
that of the circuit is approximately 15nH.
OFF
500uH
3300uF
600V
180uF
Figure 20
4.3.1 Id and Tj dependencies of switching characteristics
SiC power modules have almost zero recovery loss Err thanks to the fast recovery performance of
SiC-SBDs (or body diodes of SiC-MOSFETs). Furthermore, they have exceptionally low Eoff compared
to IGBTs due to the absence of tail current in SiC-MOSFETs. Eon and Eoff tend to increase in proportion
to currents (the proportionality varies with external Rg). Recovery current in Si-FRDs and tail current in
IGBTs become higher at high temperatures, whereas SiC modules using majority carrier devices exhibit
exceptionally small change in switching losses with increasing temperature. Also, the threshold voltage of
SiC devices decrease at high temperatures. The net effect is that SiC power modules tends to have lower
Eon and slightly higher Eoff as operating temperature increases.
19
Switching Loss vs. Drain Current
Tj=25℃
Tj=125℃
9
9
Eon
VDS=600V
8
VDS=600V
8
VGS(on)=18V
6
RG=3.9Ω
INDUCTIVE LOAD
5
VGS(on)=18V
7
VGS(off)=0V
Switching loss (mJ)
Switching loss (mJ)
7
Eoff
4
3
Eon
VGS(off)=0V
6
RG=3.9Ω
INDUCTIVE LOAD
5
Eoff
4
3
2
2
1
1
Err
Err
0
0
0
50
100
150
200
0
250
50
100
150
200
250
Drain current : Id(A)
Drain current : Id(A)
Figure 21
4.3.2 Gate resistance dependency of switching characteristics
High external gate resistance reduces charge/discharge current to/from the gate and hence the switching
rate. This may increase Eon and Eoff, which results in inferior performance. To avoid that, select a low
gate resistor wherever possible.
Switching Loss vs. Gate Resistance (Tj=25℃)
10
Eon
Switching loss (mJ)
9
Eoff
8
7
6
VDS=600V
I d=120A
VGS(on)=18V
VGS(off)=0V
INDUCTIVE LOAD
5
4
3
2
1
Err
0
1
10
100
Gate resistance Rg(Ω)
Figure 22
The following graphs show the dependency of dV/dt and dI/dt on the external gate resistance,
respectively. ROHM has conducted tests on its SiC power modules under various operating conditions.
dV/dt or dI/dt breakdown modes have never been observed in these tests.
20
dV/dt vs Gate Resistance （Tj=25℃）
Drain-source dv/dt (V/ns)
30
VDS=600V
Id=120A
25
20
VGS(on)=18V
VGS(off)=0V
INDUCTIVE LOAD
Turn off
15
10
Turn on
5
0
1
10
100
Gate resistance RG(Ω)
Figure 23
dI/dt vs Gate Resistance（Tj=25℃）
Drain-source dI/dt (A/ns)
6.0
VDS=600V
5.0
Turn off
Id=120A
VGS(on)=18V
VGS(off)=0V
INDUCTIVE LOAD
4.0
3.0
Turn on
2.0
1.0
0.0
1
10
100
Gate resistance RG(Ω)
Figure 24
4.3.3 Gate voltage dependency of switching characteristics
The maximum Vgs ratings of SiC-MOSFETs are 6V to 22V. The recommended gate drive voltages are
Vgs(on) = 18V and Vgs(off) = 0V. If used, the recommended reverse bias voltage is from 3V to 5V.
Within the specified ratings, the higher the magnitude of Vgs(on) and Vgs(off), the faster the gate is
charged/discharged, resulting in lower Eon and Eoff.
21
4.4
Comparison of switching loss with Si-IGBT power modules
The following section shows the results of comparisons of the latest 1,200V/100A half-bridge IGBT
modules produced by three different companies (as of 2012) and Rohm’s SiC module with same rating.
4.4.1 Comparison of total switching loss with Si-IGBT power modules
If appropriate external gate resistance is selected, SiC power modules can reduce a total switching loss
(Eon  Eoff  Err) by around 85% compared to state-of-the-art IGBT modules. This allows SiC power
modules to be driven at a frequency of 50 kHz or higher and therefore to use of smaller passive filter
components. Such operating conditions are difficult and generally not feasible with conventional IGBT
modules. Furthermore, IGBT modules are normally used at about half the rated current due to the high
switching loss which increases junction temperature. The current de-rating factor is much less with SiC
modules because their switching loss is much lower. In other words, SiC modules can replace IGBT
modules with higher rated current.
60
Vds=600V
Id=100A
Vg(on)=18V
Vg(off)=0V
Ta=125˚C
Inductive load
50
Esw（mJ）
40
Company A
Company B
30
20
Company C
85% reduction
10
Rohm
BSM120D12P2C005
0
1
10
100
Gate resistance Rg(Ω)
Figure 25
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
4.4.2
Comparison of diode reverse recovery loss (Err) with Si-IGBT power modules
IGBT modules incur large switching losses due to the high peak reverse recovery current of Si-FRDs.
SiC-SBDs have exceptionally low Irr and short ｔrr. Consequently, SiC modules have negligibly small
switching losses.
22
35
Vds=600V
Id=100A
Vg(on)=18V
Vg(off)=0V
Ta=125˚C
Inductive load
30
Err（mJ）
25
20
Company A
15
Company B
Company C
Rohm
BSM120D12P2C005
10
5
0
1
10
100
Gate resistance Rg(Ω)
Figure 26
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
4.4.3 Comparison of turn-on loss (Eon) with Si-IGBT
Reverse recovery current generated by commutation current flows through the arm at the opposite side,
resulting in an increase in the turn-on switching loss of the switching device. However, Eon loss in SiC
modules is reduced thanks to its fast recovery performance. The lower the external gate resistance, the
smaller the switching loss becomes.
35
Vds=600V
Id=100A
Vg(on)=18V
Vg(off)=0V
Ta=125˚C
Inductive load
30
Eon（mJ）
25
Company A
Company C
20
15
Company B
10
5
Rohm
BSM120D12P2C005
0
1
10
Gate resistance Rg(Ω)
100
Figure 27
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
23
4.4.4 Comparison of turn-off loss (Eoff) with Si-IGBT power modules
The turn-off loss of IGBTs is due to their tail current. Their Eoff is high and is largely not dependent on
gate resistance. In contrast, SiC-MOSFETs have no tail current, allowing low-loss, ultrahigh-speed
switching. The lower the external gate resistance, the lower the switching loss becomes.
35
Vds=600V
Id=100A
Vg(on)=18V
Vg(off)=0V
Ta=125˚C
Inductive load
30
Eoff（mJ）
25
Company A
Company B
20
15
Company C
10
Rohm
BSM120D12P2C005
5
0
1
10
100
Gate resistance Rg(Ω)
Figure 28
※These data are provided to show a result of evaluation done by ROHM for your reference. ROHM does not guarantee any of the characteristics shown here.
24
5. Reliability of SiC-SBD
5.1
dV/dt and dI/dt break-down
Breakdown in the outer periphery structure of SiC-SBD caused by high dV/dt were reported for
conventional products from other suppliers. Such breakdowns have not been observed in ROHM’s SiC
SBDs at dV/dt up to 50 kV/us.
Furthermore, Si-FRDs exhibit breakdown due to the very large reverse recovery current induced by high
dI/dt. This is extremely unlikely with SiC-SBDs since they have much lower recovery current.
5.2
Results of SiC-SBD reliability tests
Table 2
25
6. Reliability of SiC-MOSFET
6.1
Reliability of gate insulating layer
Oxide is used as gate insulating layer. Its reliability directly affects SiC MOSFETs’ reliability.
Development of high-quality oxide has been a challenging problem for the industry. ROHM solved this
issue by a combination of appropriate oxide growth process and device structures. As the CCS-TDDB
(Constant Current Stress Time Dependent Dielectric Breakdown) data show, its SiC MOSFETs have
achieved quality equivalent to that of Si-MOSFETs and IGBTs.
Referring to Figure 29, QBD serves as quality indicator of the gate oxide layer. The value of 15 - 20C/cm2
is equivalent to that of Si-MOSFETs.
CCS TDDB (24mA/cm2)
DMOSFET 2.2mmx2.4mm, n=22 each
2
1
ln(-ln(1-F))
0
-1
25℃
150℃
-2
-3
Level of
Si-FET
-4
-5
0.01
0.1
1
QBD (C/cm2)
10
100
Figure 29
Even with high quality gate insulating layer, there still remains crystal defects that may cause initial
failures. ROHM uses its unique screening technologies to identify and eliminate defective devices from
the production chain.
As the result of HTGB (High Temperature Gate Bias) tests conducted at 22V and 150C, ROHM has
confirmed 1,000 operating hours without any failures and characteristic fluctuations in 1,000 devices and
a lapse of 3,000 hours in 300 devices.
26
6.2
Stability of gate threshold voltage against positive gate voltage
As the current technology level, electron traps are formed at the interface between gate insulating layer
and SiC body. Electrons can be traped and consequently increase the threshold voltage if a continuous
positive gate voltage is applied for an extended period of time. However, the shift in threshold voltage is
very small, 0.2 - 0.3V, after 1000 operating hours at 150C and Vgs = +22V. This shift is the smallest in
the industry. Since most of the traps are all filled in the first several tens of hours, the threshold is fixed
and remains stable after that.
HTGB (+22V, 150℃)
1.5
Vth shift [V]
1.0
0.5
0.0
-0.5
0
200
400
600
800
1000
Stress time [hrs]
Figure 30
6.3
Stability of gate threshold voltage against negative gate voltage
The threshold drops due to trapped holes when continuous negative voltage is applied to the gate for an
extended period of time. This threshold shift is larger than that caused by positive gate voltage, e.g., the
threshold drops by 0.5V or more when Vgs is set to 10V or more. With Rohm’s second-generation
MOSFETs (SCT2xxx series and SCH2xxx series), the shift does not exceed 0.3V, provided that the gate
is not reverse biased beyond 6V. Negative gate voltage lower than 6V causes a significant drop in the
threshold.
In normal operation, gate voltage alternates between positive and negative biases and thus repeatedly
charges and discharges the traps making unlikely to have significant changes in the threshold.
27
HTGB (-6V, 150℃)
0.5
Vth shift [V]
0
-0.5
-1
-1.5
0
200
400
600
800
Stress time [hrs]
1000
Figure 31
Vth shift [V] after 1000h
0.5
Maximum Vgs
rating -6V
0
-0.5
(500h)
-1
0
-2
-4
-6
-8
-10
-12
-14
-16
-1.5
applied Vgs [V]
Figure 32
6.4
Reliability of body diodes
Another mechanism that affects SiC MOSFET’s reliability is the degradation caused by its body diode’s
conduction. If forward current is continually applied to SiC P-N junction such as body diodes in
MOSFETs, a plane defect called stacking fault will be extended due to the hole-electron recombination
energy. Such faults block the current pathway, thus increasing on-resistance and Vf of the diode.
Increasing the on-resistance by several times disrupts the thermal design. Furthermore stacking faults may
degrade the blocking voltage. For this reason, using SiC MOSFETs whose body diodes degrade with
28
conduction in circuit topologies that causes commutation to the body diode, e.g. bridge topologies in
inverters, might result in serious problems. This reliability problem only occurs with bipolar devices, not
with SiC-SBDs and the first-quadrant operation of SiC-MOSFETs.
ROHM has reduced crystal defects in SiC wafers and epitaxial layers and developed the proprietary
process that prevents propagation of stacking faults, ensuring the reliability of body diode conduction.
This is confirmed in 8A DC, 1,000-hour conduction tests which shows no degradation in all
characteristics, including on-resistance and leakage current. This ensures worry-free use of
SiC-MOSFETs in circuits that cause commutation to the body diodes.
Furthermore, reverse conduction reliability tests with Vgs = 18V and Id = 15A DC (also 1,000-hour) also
shows no significant changes in electrical characteristics.
Body-diode conduction test (If=8A DC, Ta=25oC, 1000h)
DUT: SCT2080KE (TO247 w/o SiC SBD),
Ron
Idss
Idss
Ron
1.E-05
n=20
n=20
Idss（A） @ Vds=1.2kV
Ron （Ω ） @ Id=10A, Vgs=18V
0.40
0.30
No degradation
0.20
0.10
1.E-06
No degradation
1.E-07
1.E-08
1.E-09
0.00
0
100 200 300 400 500 600 700 800 900 1000
0
100 200 300 400 500 600 700 800 900 1000
STRESS TIME (h)
STRESS TIME (h)
Figure 33
6.5
Short circuit safe operation area
Since SiC-MOSFETs have smaller chip area and higher current density than Si devices, they tend to have
lower short circuit withstand capability (thermal fracture mode) compared to the Si devices. 1,200V
SiC-MOSFETs in TO247 package have short circuit withstand time (SCWT) of approximately 8 to 10 s
when Vdd is set to 700V and Vgs is set to 18V. SCWT is longer with lower gate voltage, which reduces
saturation current and ｌower power supply voltage, which generate less heat.
Many gate driver ICs incorporate functions that simplify detection and management of short circuit
condition. For example, Rohm’s BM6103FV-C can shutdown the switch in approximately 2 s once over
current is detected. It has soft turn-off capability to gradually reduce the gate voltage during turnoff to
29
prevent high surge voltage, which is induced by high dI/dt across the drain and source inductance. It is
advised to pay careful attention not to apply over voltage by using such a soft turn on function or other
preventative measures.
6.6
dV/dt breakdown
Si-MOSFETs involve a breakdown mode in which high dV/dt causes transient current to pass through the
capacitance Cds and turn on the parasitic bipolar transistor, leading to device breakdown. This is less
likely an issue with SiC-MOSFETs since the current gain of their parasitic bipolar transistors are low. So
far such breakdown mode has never been observed with ROHM’s SiC-MOSFETs operating with dV/dt at
up to 50 kV/s.
Since SiC-MOSFETs generate exceptionally low recovery current, reverse recovery current also will not
cause high dV/dt. Consequently, SiC-MOSFETs are considered unlikely to cause this breakdown mode.
6.7
Neutron-induced single event burnout
In high-altitude applications, random failures such as SEB (single event burnout) of semiconductor
devices caused by neutrons or heavy ions become an issue. Irradiation tests of white neutron beam
(energy: 1 to 400MeV) on Rohm’s 1,200V SiC-MOSFETs were conducted at the Research Center for
Nuclear Physics, Osaka University (RCNP). On the 5 test samples, there were no failures due to single
event phenomenon with an irradiation fluence of 1.87109[neutron/cm2] with Vds set to 840V (equivalent
to 70% of the rated breakdown voltage). The failure rate is calculated to be less than 1.37FIT at 0 m
above sea level and less than 35.3FIT at 4,000 m above sea level ( “less than” because there’s no failure).
This indicates that SiC-MOSFETs present no problems in high-altitude applications. Since
SiC-MOSFETs are relatively small in chip size compared to Si devices and ROHM’s SiC MOSFETs
have adequate breakdown voltage margin, they can have a low failure rate from cosmic ray radiation.
6.8
Electrostatic discharge withstand capability
The smaller chip size of SiC MOSFETs means lower electrostatic discharge (ESD) withstand capability
relative to silicon devices. Therefore it’s advised to handle SiC devices with adequate ESD protection
measures.
Examples of ESD protection measures
･Eliminate static electricity from human body, devices, and work environment using ionizers.
･Eliminate static electricity from human body and work environment using wristbands and grounding.
This measure is ineffective against charged devices.
30
6.9
Results of SiC-MOSFET reliability tests
寿命試験 (Life Test)
試験項目
Test Item
試験方法／準拠規格
Test Method/Standard
高温逆バイアス試験
Ta=Tjmax、VDS=Vrmax X 0.8
High Temperature Reverse Bias
EIAJ ED-4701/100-101
高温ゲートバイアス試験
Ta=Tjmax、VGS =+22V
High Temperature Gate Bias
EIAJ ED-4701/100-101
高温ゲートバイアス試験
Ta=Tjmax、VGS = -6V
High Temperature Gate Bias
EIAJ ED-4701/100-101
高温高湿バイアス
Ta=85℃、Rh=85%、VDS=100V
Temperature humidity bias
EIAJ ED-4701/100-102
温度サイクル
Ta= -55℃ (30min) ～ Ta=150℃ (30min)
Temperature cycle
EIAJ ED-4701/100-105
蒸気加圧
Ta=121℃、2atm、Rh=100%
Pressure cooker
JESD22-A102C
高温保存
Ta= 150℃
High Temperature storage
EIAJ ED-4701/100-201
低温保存
Ta= -55℃
Low Temperature storage
EIAJ ED-4701/100-202
試験時間
Test Condition
サンプル数
n(pcs)
不良数
pn
1000h
22
0
1000h
22
0
1000h
22
0
1000h
22
0
100cycle
22
0
48h
22
0
1000h
22
0
1000h
22
0
試験時間
Test Condition
サンプル数
n(pcs)
不良数
pn
10sec
22
0
3.5sec
22
0
5sec
22
0
100cycle
22
0
10sec
22
0
2times
22
0
強度試験 (Stress Test)
試験項目
Test Item
はんだ耐熱性1
Resistance to solder heat1
試験方法／準拠規格
Test Method/Standard
260±5℃のはんだ槽に端子を浸漬
Dipping leads into solder bath at 260±5℃.
EIAJ ED-4701/300-302
はんだ耐熱性2
Resistance to solder heat2
350±10℃のはんだ槽に端子を浸漬
Dipping leads into solder bath at 350±10℃.
EIAJ ED-4701/300-302
はんだ付け性
Solderability
235±5℃のはんだ槽に浸漬
Dipping into solder bath at 235±5℃.
EIAJ ED-4701/300-303
+5
-0
(5min) ～ 100+0
(5min)
-5
熱衝撃
0
Thermal shock
EIAJ ED-4701/300-307
端子強度 (引張り)
引張力 ； 20N
Pull force ; 20N
Terminal strength (Pull)
EIAJ ED-4701/400-401
端子強度 (曲げ)
Terminal strength (Bending)
曲げ荷重 ； 10N
Bending load ; 10N
EIAJ ED-4701/400-401
※ 故障判定は仕様書に記載されている電気的特性にて行っています。
Failure criteria : According to the electrical characteristics specified by the specification.
はんだ付け性試験については濡れ面積≧95%にて判定しています。
Regarding solderability test, failure criteria is 95% or more area covered with solder.
※ ｻﾝﾌﾟﾙ基準：信頼度水準90%,不合格信頼性水準λ1=10%,C=0判定を採用し,MIL-STD-19500の指数分布型計数1回抜取表に従い,ｻﾝﾌﾟﾙを22個としています。
Sample standard:[Reliability level:90%][Failure reliability level(λ1):10%][C=0 decision] is adopted. And the number of samples is being made 22 in
accordance with single sampling inspection plan with exponential distribution type based on MIL-STD-19500.
Table 3
31
7. Instructions to use SiC power modules and their reliability
7.1
Measures to reduce surge voltage
Since SiC modules support high switching speed and handles high currents, surge voltage (VLdI/dt)
is generated due to wire inductance L in the module or at its periphery and may exceed the rated voltage.
Below is a list of recommendations to prevent or mitigate this problem. However, these measures may
have an impact on the switching performance.
･ Reduce wire inductance by using thick and short wirings in both main and snubber circuits.
・ Place capacitors close to MOSFETs to reduce wire inductance.
･ Add snubber circuit
･ Increase gate resistance to reduce dI/dt
Examples of snubber circuits
＜C snubber circuit＞
＜RC snubber circuit＞
＜RCD snubber circuit＞
Figure 34
7.2
Bridge arm short circuit by self turn-on
Referring to Figure 35 below, when the MOSFET M1 of the upper arm of a half bridge turns on, reverse
recovery current flows through the freewheeling diode (external SiC-SBD or body diode) of the
MOSFET M2 of the lower arm and raises the drain-source voltage of M2. Due to this dV/dt, transient
gate current (ICrssdV/dt) through the reverse transfer capacitance Crss of M2 flows into the gate
resistance, thus resulting in a rise in the gate voltage of M2. If this voltage rise exceeds the gate threshold
voltage of M2, short-circuit current flows through both the upper and the lower arms.
32
I
Figure 35
While the threshold voltage of SiC-MOSFET defined at several milli-amperes is as low as around 3V, the
gate voltage required to conduct high current is 8V or higher. As a result, withstand capability of bridge
arm short circuit is not significantly different from that of IGBTs. However, to prevent this unexpected
short circuit, it is recommended to take measures listed below which are also valid for Si power modules.
However, these measures may influence the switching performance. Adjustment of the circuit with
monitoring waveforms to prevent self turn-off is advised.
・ Increase negative gate bias voltage to turn OFF the MOSFET.
・ Add a capacitor between the gate and the source.
・ Add a transistor between the gate and the source that clamps Vgs to ground when the switch is off
・ Increase the gate resistance to reduce the switching rate.
7.3
RBSOA (Reverse bias safe operating area)
Like IGBT modules, the RBSOA (Reverse Bias Safe Operating Area) of SiC power modules covers the
entire range of twice the rated current  Rated voltage.
33
7.4
Results of SiC power module reliability tests
Figure 36
34
8. Definition of part number
8.1 SiC-SBD (discrete components)
S
C
①
S
2
②
③
2
0
④
A
G
⑤
⑥
①
②
③
④
Code stands for SiC
Code stands for SBD
Generation of the device
Rating Current [in A]
0 5→ 5A
2 0→20A
A: 600V, 650V
⑤ Voltage
K: 1200V
E2: TO247 [3pin, 2dice]
⑥ Package
G: TO220AC [2pin]
J: LPTL [D2PAK]
M: TO220FM [2pin]
8.2 SiC-MOSFET (discrete components)
S
C
①
T
2
②
③
0
8
④
0
K
E
⑤
⑥
① Code stands for SiC
② Code stands for product type T: ＭＯＳＦＥＴ
H: ＭＯＳＦＥＴ+SBD
③ Generation of the device
0 8 0: typ. 80mΩ
④ Rdson [in mΩ]
1 6 0: typ. 160mΩ
A: 600V, 650V
⑤ Voltage
K: 1200V
⑥ Package
E: TO247
F: TO220AB
35
8.3 SiC Power Modules
B
S
M
1
①
0
2
②
①
②
③
④
1
D
P
2
④
③
2
⑤
Code stands for SiC power module
Rating current [in A]
Half bridge
Voltage
⑤ Type and generation of the device
⑥ Module case
⑦ Added number
0
C
⑥
0
1
⑦
1 2 0: 120A
1 2: 1200V
1 7: 1700V
8.4 SiC-SBD (bare dice)
S
6
2
①
②
③
0
1
④
① Code stands for SiC
② Code stands for SBD
③ Generation and voltage
0: 1G 600V
1: 1G 1200V
2: 2G 600V/650V
3: 2G 1200V
4: 2G 1700V
④ Added number
8.5 SiC-MOSFET (bare dice)
S
2
3
①
②
③
0
1
④
① Code stands for SiC
② Code stands for MOSFET
③ Generation and voltage
2: 2G 650V
3: 2G 1200V
4: 2G 1700V
④ Added number
36
9. Examples of applications and benefits of using SiC
9.1 Power factor correction (PFC) circuits (CCM - Continuous conduction mode)
・Improvement of conversion efficiency and noise reduction due to elimination of reverse recovery current
・Downsizing of passive filter components under high frequency operation achieved by low Err
*No significant improvement is expected for critical conduction mode PFC as reverse recovery current
from the diode does not influence the total conversion loss.
Recommended P/N
SCS2□□AM, SCS2□□AG,
SCS2□□AE2, SCS2□□KG,
SCS2□□KE2
9.2 Solar inverters
・Reduction in Eoff, Err and conduction loss at low load condition
・Downsizing of a cooling system for power devices
Recommended P/N
SCT2□□□KE, SCH2□□□KE
BSM120D12P2C005,
BSM180D12P2C101
9.3 DC/DC converters
・Reduction in Eoff, Err and downsizing of a cooling system for power devices
・Downsizing of transformer under high frequency operations
Recommended P/N (primary side)
SCT2□□□KE, SCH2□□□KE
BSM120D12P2C005,
BSM180D12P2C101
Recommended P/N (secondary side)
SCS2□□AM, SCS2□□AG,
SCS2□□AE2, SCS2□□KG,
SCS2□□KE2
37
9.4 Bi-directional converters
・Downsizing of passive filter components in high frequency operations
・Reduction in Eoff, Err and size reduction of cooling system for power devices
Recommended P/N
SCT2□□□KE, SCH2□□□KE
BSM120D12P2C005,
BSM180D12P2C101
9.5 Inverters for induction heating equipment
・Enlargement of operable conditions by increased frequency
・Reduction in Eoff, Err and downsizing of a cooling system for power devices
Recommended P/N
SCT2□□□KE, SCH2□□□KE
BSM120D12P2C005,
BSM180D12P2C101
9.6 Motor drive inverters
・Reduction in Eoff, Err and downsizing of a cooling system for power devices
Recommended P/N
SCT2□□□KE, SCH2□□□KE
BSM120D12P2C005,
BSM180D12P2C101 他
38
9.7 Buck converters
・Reduction in Eoff and downsizing of a cooling system for power devices
・Downsizing of passive filter components
Recommended P/N
SCT2□□□KE
SCS2□□AM, SCS2□□AG,
SCS2□□AE2, SCS2□□KG,
SCS2□□KE2
*Buck converters operating in DCM (discontinuous conduction mode) and BCM (boundary conduction
mode; also called critical conduction mode) do not benefit from SiC SBDs’ recovery performance.
39
Notice
Notes
1) The information contained herein is subject to change without notice.
2) Before you use our Products, please contact our sales representative and verify the latest specifications :
3) Although ROHM is continuously working to improve product reliability and quality, semiconductors can break down and malfunction due to various factors.
Therefore, in order to prevent personal injury or fire arising from failure, please take safety
measures such as complying with the derating characteristics, implementing redundant and
fire prevention designs, and utilizing backups and fail-safe procedures. ROHM shall have no
responsibility for any damages arising out of the use of our Poducts beyond the rating specified by
ROHM.
4) Examples of application circuits, circuit constants and any other information contained herein are
provided only to illustrate the standard usage and operations of the Products. The peripheral
conditions must be taken into account when designing circuits for mass production.
5) The technical information specified herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or implicitly,
any license to use or exercise intellectual property or other rights held by ROHM or any other
parties. ROHM shall have no responsibility whatsoever for any dispute arising out of the use of
such technical information.
6) The Products specified in this document are not designed to be radiation tolerant.
7) For use of our Products in applications requiring a high degree of reliability (as exemplified
below), please contact and consult with a ROHM representative : transportation equipment (i.e.
cars, ships, trains), primary communication equipment, traffic lights, fire/crime prevention, safety
equipment, medical systems, servers, solar cells, and power transmission systems.
8) Do not use our Products in applications requiring extremely high reliability, such as aerospace
equipment, nuclear power control systems, and submarine repeaters.
9) ROHM shall have no responsibility for any damages or injury arising from non-compliance with
the recommended usage conditions and specifications contained herein.
10) ROHM has used reasonable care to ensur the accuracy of the information contained in this
document. However, ROHM does not warrants that such information is error-free, and ROHM
shall have no responsibility for any damages arising from any inaccuracy or misprint of such
information.
11) Please use the Products in accordance with any applicable environmental laws and regulations,
such as the RoHS Directive. For more details, including RoHS compatibility, please contact a
ROHM sales office. ROHM shall have no responsibility for any damages or losses resulting
non-compliance with any applicable laws or regulations.
12) When providing our Products and technologies contained in this document to other countries,
you must abide by the procedures and provisions stipulated in all applicable export laws and
regulations, including without limitation the US Export Administration Regulations and the Foreign
Exchange and Foreign Trade Act.
13) This document, in part or in whole, may not be reprinted or reproduced without prior consent of
ROHM.
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