Electronic – Maximum Transistor current and voltage


Assuming we have a transistor that can bear 400v 0.3A, is that means it can bear 30A if we used it for 4v only or it always withstand 0.3A?
(since P1 = P2 = 0.3 * 400 = 30 * 4)

Best Answer

Many power transistors have a SOA (Safe Operating Area) graph in their datasheet, here's an example:

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The safe area is the bottom left side so:

Vce = 5 V at Ic = 20 Amps is just OK


Vce = 50 V at Ic = 2 Amps is not

Also note that it states Tc = 25 degrees Celcius meaning you have to cool this device such that its case will not exceed 25 degrees Celcius.

Also not that for a limited time, the device can handle a little higher value. It is not clear how much time it needs to recover after such an event.