Electronic – the meaning of collector current pulse in the datasheet

ratingstransistors

Here is the datasheet of a transistor:
http://www.adafruit.com/datasheets/TIP120.pdf

In maximum ratings, there is a section called "Collector Current (Pulse)".
What does that mean in practice?

Lets say this transistor is applied 30V constant DC to its ends.
So the max. collector current should not exceed 5A.
But if the applied 30V is in the shape of a pulse with lets say %99 duty cycle will the max. current be 8A? Thats what I understand but Im not sure.

Best Answer

Here's a guide published by On Semiconductor on how to interpret their IGBT datasheets. It says that:

The pulsed collector current describes the peak collector current pulse above the rated collector current specification that can flow while remaining below the maximum junction temperature. The maximum allowable pulsed current in turn depends on the pulse width, duty cycle and thermal conditions of the device. (P. 2)