voltage stress across switching devices

[julioreye]

Stressing devices

somebody can describe me what's the voltage stress across switching devices. in a igbt 3-phase module, for example.

 

[Mr.Cool]

the voltage stress is a ratio between the applied worse case voltage and the rating of the device. the higher the applied voltage, the more margin you will need. i.e. in 5V applications, you can have 80% stress. in 500V applications you can have 60% stress. (just rules of thumb here)

note that i said WORSE CASE voltage.. this is NOT your nominal applied voltage.. but is usually some transient value. there are many things that can cause a transient.. i hope you know which is the worse one for your application.

Mr.Cool