Since a PNP transistor or mosfet switches off when certain amount of current or voltage is applied to it or shuts off when any current or voltage is applied to it's base can you over heat or blow up a PNP transistor or mosfet by applying to much current/voltage to it's base or will it just shut the transistor or mosfet off. Thanks.

 

In case of MOSFET if Vgs gets too high the gate oxide will rupture internally
causing (typically) a short and is destructive.

In case of Bipolar too much base current can create extreme junction heating,
can melt internal silicon, can destroy gain of transistor, can simply wind up
shorting one or more junctions.

Regards, Dana.

 

Since a PNP transistor or mosfet switches off when certain amount of current or voltage is applied to it

Where did you get that idea?

Current in the base emitter junction turns a PNP or NPN transistor on, not off.

Bob

 

In fact this is why the mosfets are sensitive to electrostatic discharge. High voltage from ESD can permanently damage mosfets and should handled with care before they are placed in circuitry. This includes ICs.

 

The data sheet for a specific device will tell you the maximum voltages and currents it can tolerate.

 

... can you over heat or blow up a PNP transistor or mosfet by applying to much current/voltage to it's base or will it just shut the transistor or mosfet off. Thanks.

It will be destroyed. Unlike some ICs, a discrete transistor has no overload protection. If you exceed the specifications, you risk immediate failure. And since transistors can fail to a short, they can bring down other components as well. Many devices will have a fuse on board to prevent a transistor failure (or other problem) from causing a fire.