MT5F33743
1. Maximum Junction Temperature
T
vjmax
© Fuji Electric Co., Ltd. All rights reserved.
As described in specification sheet, this automotive IGBT module can be used under
T
vj
=175
℃
.
However, if junction temperature under operation is close to the maximum ratings, the products life
time degradation might be happened by expediting thermal fatigue destruction.
Therefore, to keep safety operation, please use the product under suitable operating conditions.
This chapter describes precautions for actual operation of the IGBT module.
5-2
2. Short-Circuit Protection
When IGBT is to be short-circuit state, Collector current is increased and
V
CE
voltage is rapidly
increased. From this characteristics, although Collector current is limited certain level under
short-circuit state, high power due to high voltage and high current is apply to the IGBT at this
moment. Therefore, this severe state should be removed as soon as possible.
An example by using gate driver IC which has short-circuit protection function is shown in chapter 7,
please refer it.
As it is explained in chapter 1, this IGBT module has on-chip current detecting sensor. Its function
and characteristics are shown in chapter 8.
So please use this on-chip sensor for short-circuit protection function suitably.
On the other, because this IGBT module does not have corrector voltage detecting point on each
arm, desaturation type of short-circuit protection method shall not be used to avoid any unexpected
trouble.
3. Overvoltage Protection and Safety Operation Area
3.1 Overvoltage protection
Because switching speed of IGBT is very fast, large d
i
/d
t
is produced in turn-off operation or reverse
recovery. So from this large d
i
/d
t
and inductance component contained inside and outside this module
surge voltage is produced. If this surge voltage is excessed the device breakdown voltage, the device
is in overvoltage state and it would be destructed in the worst case. Followings are some examples to
avoid this kind of worst case:
1) Add snubber circuit 2) Tune the gate resistance 3) Reduce inductance in the main circuit
Images of turn-off waveform and reverse recovery waveform are shown in Fig. 5-1 and surge voltage
is defined.
(a) Turn-off
(b) Reverse recovery
Fig. 5-1 Turn-off waveform, reverse recovery waveform and surge voltage
V
AK
I
C
V
AKP
0
0
V
CE
I
C
V
CEP
0
0
