IEEE Power Electronics Magazine - September 2020 - 48

Load

GP

RG

VDS

VGS GN

0
-VGS

EN

VDD

iD
×N

FIG 9 Double pulse measurement circuit.

200
Si

175

Esw (mJ)

150
125

SiC
Eon

Eon

Eoff
Err

Eoff
Err

100
75
50
25
0

0

100

200

300

400

500

IC-IE/ID-IS (A)
FIG 10 Switching loss characteristics Conditions: 125 °C, VGE =
+15 V/−12 V, 1000 Vdc, RG(Si) = 0 Ω, RGon(SiC) = 3.4 Ω, RGoff(SiC)
= 10 Ω, inductive load.

Turn On
SiC
Vce
Ic

Vds
Id

200

400
600
Time (ns)
(a)

800

1,000

550
500
450
400
350
300
250
200
150
100
50
0
-50

Turn Off

400

1,400

350

1,200

300
Current (A)

Si

Voltage (V)

1,200
1,100
1,000
900
800
700
600
500
400
300
200
100
0
-100 0

Current (A)

+VGS

+

×OUT

EP

1,000

250

800

200

Si

150

SiC
Vce
Ic

100

Vds
Id

0
200

400
600
Time (ns)
(b)

800

1,000 -200

FIG 11 Switching waveforms; IGBT/SiC MOSFET 300 A, 1000 VDC, 125 °C, RG(SI)=0 Ω, RGON(SiC) = 3.4 Ω, RGOFF(SiC) = 10 Ω.

48

IEEE POWER ELECTRONICS MAGAZINE

z	September 2020

400
200

50
0
-50 0

600

Voltage (V)

×P

-VGS

the double pulse test setup shown physically in Figure 8
and schematically Figure 9. Device current is measured
using a low insertion inductance current transformer per
Reference 4. The Isahaya Electronics VLA586-01R gate
driver was used for both the Si IGBT and SiC MOSFET
module. This gate driver provides a gate bias of +15 V/−12 V.
Gate resistance values of R G (Si) = 0 X, R Gon (SiC) = 3.4 X,
and R Goff (SiC) = 10 X) were used for the initial switching
loss comparison.
Figure 10 shows the results of the turn-on (E on), turnoff (E off ), and reverse recovery (E rr) switching losses from
0-550 A. At 300 A, the total switching loss [E sw = E on + E off + E rr]
of the Si module is 170.8 mJ. The SiC module measured total
switching loss of E sw = 46.2 mJ is 73% lower than the comparable Si module. By taking advantage of the SiC module's 73%
reduction in E sw, larger power electronics systems can make
significant increases in operating frequency, performance,
and/or overall efficiency.
Figure 11 shows the turn-on and turn-off switching
waveforms of the Si IGBT and SiC MOSFET modules.
Due to the SiC MOSFET characteristics, switching
speed is increased and loss is greatly reduced compared
to the Si IGBT module. At the conditions shown in Figure 11(b), the maximum dv/dt at turn-off is 7.9 kV/ns for
the Si module while the SiC module has a maximum dv/
dt of 15.4 kV/ns. The peak surge voltage of the Si module
reached 1174 V while the SiC module had a peak surge
voltage of 1258 V. To take advantage of the fast switching speed of the SiC module, proper gate drive, a low
inductance decoupling capacitor on the module terminals, and a low inductance DC link is required. With the
proper external hardware, even faster switching speeds
are possible with the SiC module.
R G Controllability: Double pulse tests were completed with several gate resistor values ranging from datasheet minimum to maximum values for both the Si and

is
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