Confusions about the Safe Operating Area of Diodes

[YaoComp]

Hi, recently, during the selection of IGBT modules, I discovered that some data sheets provide Safe Operating Areas(SOA) for diodes , while others do not. Moreover, the diode SOA of different modules  are different, which makes me confused😵. Could you please answer the following three questions for me:
1. Why do some IGBT modules provide diode SOA, while others do not?
2. Why are the diode SOA different for different IGBT modules? I mean some IGBT modules have a rectangular diode SOA that is not subject to PRQM restrictions, while others are subject to PRQM restrictions.
3. Is PRQM obtained through calculation or experiment? If calculation, how is it calculated? Is there any relevant references?

Thanks a lot, very much, a million！

[Anil_Y · Accepted solution]

Dear @YaoComp ,

Good day!!

Thanks for posting your query in Infineon community.

1) In some applications diodes are not intended to carry rated current, where no need to check for SOA of the diode. In those modules we haven't provided diode SOA curve.

2)For SiC diode reverse recovery losses are less when compared to Si diode, so  parabolic nature in SOA curve of SiC diodes may disappear slightly which will appear like rectangular.

3) PQRM(peak power loss)  is just multiplication of instantaneous values of reverse voltage and reverse recovery current. { PQRM = Vr(t) * Irr(t) }

Best Regards,

Anil Kumar.