MA300E12_EVAL Infineon Technologies, MA300E12_EVAL Datasheet - Page 11

• Manufacturer Part Number: MA300E12_EVAL
• Description: Power Management IC Development Tools MOD ADPTR BRD FOR 1200V PRIMEPACK IGBT
• Manufacturer: Infineon Technologies

Module Adapter Board
for PrimePACK
3.4
If the IGBT transistor conducts a current a few times higher than the nominal value, the transistor
desaturates and the V
switching-off an IGBT transistor. The short circuit withstand time for Infineon high power IGBT
modules is ≤ 10µs. During this time the short circuit should be detected and the IGBT should be
switched off without exceeding V
When MA300Exx is used together with 2ED300E17-SFO the R
chosen correctly in order to insure proper short circuit protection. The detailed procedure is described
in AN2007-05 chapter 3.5.
Figure 9a shows three FF1000R17IE4 PrimePACK™ modules under short circuit operation where
short circuit protection on the 2ED300E17-SFO was disabled. High dI
a large overvoltage spike which is limited by active voltage clamping. Figure 9b depicts how a properly
selected R
turning off.
Figure 9
3.5
Active voltage clamping is a technique which keeps transient V
IGBT switches off. The standard approach to active clamping is to use a chain of avalanche diodes
connected between the auxiliary collector and the gate of an IGBT module. When the V
exceeds the diodes breakdown voltage the diodes current sums with the current from the driver
output. Due to increased gate-emitter voltage the transistor is held in an active mode and the turn off
process is extended. The dI
Avalanche diodes conduct high peak currents during time period in which V
Overvoltage protection of the MA300EXX is based on an improved variant of the active clamping as
described above. The clamping diodes are connected directly to the IGBTs gate but also to the input
of the amplifier located on the MA300EXX. Therefore the major amount of current for recharging the
gate is derived from the gate driver power supply instead of via the clamping diodes. This provides
more consistent clamping voltage due to operating the clamping diodes at a lower current level and
furthermore enables the clamping circuit to be designed independently from the selected external gate
resistor. Finally the same circuit for 1200V and 1700V modules using different diodes types has been
realized and is shown in Fig. 1.
V
V
200V/div
200V/div
2µs/div
2µs/div
CE
CE
SSD
V
Switching behavior of three paralleled FF1000R17IE4 PrimePACK™ modules under
short circuit where system with the 2ED300E17-SFO and MA300E17 applied:
short circuit protection disabled 9a and enabled 9b
Active voltage clamping – boosted version
resistor limits the short circuit time (<10µs) and slows down the collector current when is
CE
monitoring for short circuit detection
I
I
1kAV/div
1kAV/div
C1
C1
,
,
I
I
TM
CE
C2
C2
,
,
voltage increases. This behavior can be used for short circuit detection and
I
I
C3
C3
IGBT Modules
C
/dt slows down to a value which results in limited V
CES
.
9a
11
V
V
200V/div
200V/div
2µs/div
2µs/div
CE
CE
SSD
9b
CE
resistors (Soft Shut Down) must be
overvoltages below V
C
/dt during switching off creates
CE
overvoltage is limited.
I
I
1kAV/div
1kAV/div
C1
C1
Application Note AN 2007-06
,
,
I
I
C2
C2
,
,
I
I
V1.2, June 2010
C3
C3
CE
CES
overshoot.
CE
when the
voltage