Power integrations Scale-2 1SC0450E2B0, Руководство по применению, Страница: 14 / 25

SCALE™-2 1SC0450E2B0
Preliminary Description & Application Manual
www.power.com/igbt-driver Page 14
Recommended values for 3300V IGBTs with DC-link voltages up to 2200V
 R
vce1
=R
vce2
=…=R
vce14
=220kΩ (500mW, 400V
peak
, 1%)
 R
div
=1.5MΩ (0603, 1%)
 C
vce1
=15pF (C0G, 1000V, 5%)
 C
vce2
=C
vce3
=…=C
vce7
=22pF (C0G, 630V, 5%)
 C
a
=22pF (C0G, 50V, 5%)
 R
th
=not assembled
 R
a
=refer to Table 3 below (0603, 1%)
This setup uses 14 resistors R
vcei
and 7 capacitors C
vcek
per channel and leads to a static desaturation
detection threshold of about 50V.
V
DC-Link
R
a
=68kΩ R
a
=91kΩ R
a
=120kΩ
2200V 5.3µs 7.0µs 9.0µs
1500V 5.3µs 7.0µs 9.0µs
1100V 5.4µs 7.0µs 9.1µs
700V 7.6µs 8.1µs 9.3µs
600V 17.0µs 14.4µs 13.7µs
Table 3 Typical response time as a function of the resistance R
a
and the DC-link voltage V
DC-Link
Table 3 gives indicative values only. The response time depends on the specific layout and the IGBT module
used. It is therefore recommended to measure the short-circuit duration in the final design.
Note that slow IGBT modules may report a wrong V
CE
desaturation fault at turn-on. It is therefore
recommended to test the setup under worst case conditions (maximum DC-link voltage, maximum collector
current and highest IGBT junction temperature). Please also refer to AN-1101 /4/ for more information.
Input for adjusting the turn-off delay in fault condition (CSHD)
The terminal CSHD allows the delay in turning off the IGBT after a fault detection on the driver’s secondary
side (short-circuit, undervoltage, external fault input) to be determined with a capacitor C
cshd
(C0G/50V) with
a maximum value of 10nF connected to COM. Table 4 shows the resulting delay as a function of the circuit
used at pin CSHD.
Circuit at pin CSHD Typical turn-off delay T
cshd
Left open: T
cshd
=0.2μs Eq. 9
Capacitor between CSHD and COM: T
cshd
[μs]=
C
cshd
[pF]
50
(C
cshd
≤10nF) Eq. 10
Table 4 Turn-off delay as a function of CSHD wiring
As soon as the fault turn-off delay time T
cshd
has elapsed, the driver’s channel is automatically turned off.
The driver’s channel can also be turned off from the driver’s input IN within the turn-off delay time T
cshd
determined by the CSHD pin after a secondary-side fault detection.
Note that it will not be possible to turn the IGBT on during about 100ns per 100pF capacitance applied to
CSHD after a fault condition, starting from the turn-off event of the IGBT (minimum off-time required).