I have some IGBT modules and have some questions about not just these but all heavy duty IGBT modules in general.

In the schematics of the modules they have an extra connection for the emitters. Not the main connection but a smaller one that goes to another part of a circuit. The question is what is this for? How is it used?

In the second IGBT they show a TVS-diode from the gate to the emitter. but no information as to its use or the value. What is it for? Never seen one in any other IGBT modules.

 

The smaller emitter terminal is the return path for the gate drive signal.

I assume the TVS diode to be a protection for the gate terminal, to make sure it doesn't exceed the maximum rating (+-20V).

 

Thank you again for sharing your knowledge.