Desaturation in IGBT : what does it really mean?

[pawan kumar]

Hi Friends,

Somehow, i do not understand this word completely. I came across "Desaturation" in IGBT because of a circuit which was a 3Phase AC motor driver.

There's a block which senses that the IGBT is coming close to Desaturation and prevents it through a slow stop signal at it's Gate (Base).

They say that when this Desaturation occurs, there is an increase in the collector potential : Does that mean the transistor go into Active region? Please help me understand guys. Here is a schematic which I am referring to :



Thanks,
Pawan

 

[schmitt trigger]

Hi Friends,

They say that when this Desaturation occurs, there is an increase in the collector potential : Does that mean the transistor go into Active region? Please help me understand guys. Here is a schematic which I am referring to :
Thanks,
Pawan

That is correct.
And as you well know, in the active region the power dissipation increases dramatically.

 

[pawan kumar]

That is correct.
And as you well know, in the active region the power dissipation increases dramatically.

That was quick.. thanks Schmitt Trigger