Whether or not this behaviour shows in the individual power semiconductor depends on
the chip technology, the voltage rating of the power semiconductor as well as the load
shows an example of two IGBTmodules (1.2kV and 1.7kV Trench-FS
IGBTs eachwith 450A nominal current) operatedwith different on-times t
load currents I
. This example shows for the 1.2kV IGBTmodule for short on-times
of approx. 4µs to 8µs an increase in voltage overshoot at nominal and twice nominal
current. The 1.7kV IGBTmodule, however, shows a reduced over-voltage to beginwith,
which reaches its maximum with a time of around 3µs to 6µs before it drops to lower
). The peak diode current in the 1.7kVmodule shows none or only a
small dependency on theminimal on-time except when operated with twice the current.
At twice over-current the current overshoot is strongly reduced, however. The 1.2kV
IGBT module shows a different behaviour. With nominal current there is an overshoot
up to around 6µs whereas there is virtually no dependency on the on-time for all other
Voltage overshoot (IGBT) and reverse recovery current (diode) of 1.2kV and
1.7kVpower semiconductorswith different load currents and on-times
Often there are oscillations with short on-times.
depicts a comparison of a
450A/1.2kV Trench-FS IGBTmodulewhere the IGBT is turned on at U
= 700V and I
= 900A for 1µs one time and for 20µs another time.