What happens if you reverse a transistor?

What happens if you reverse a transistor?

Now, if you use the transistor in reverse, the emitter becomes the collector and the collector becomes the emitter, and its quite simple to see what happens: (1). As the collector doping is less than the emitter doping, the hole current in the collector (now the emitter) increases, leading to lower beta.

What causes transistors to get hot?

If you try to share current from one resistor, one transistor will get more of the current, causing it to warm up, which drops the Vbe even more, which causes it to get even more current.

What is the difference between emitter and collector?

The main differences between emitter and collector are doping concentration and size. The emitter is heavily doped, while the collector is lightly doped. You could try to swap them, but you’ll get a very low HFE, probably even less than 1.

Is collector and emitter interchangeable?

Are the collector and emitter terminals of a bipolar transistor interchangeable? No. Transistors are designed to provide the optimum performance when they are correctly connected.

Does transistor direction matter?

Yes current can flow in both directions. An NPN transistor backwards is also an NPN. There will still be a reverse beta, however, the backwards NPN transistor won’t work as well as a correctly oriented one will. It’s not recommended.

Can you overload a transistor?

Most “overloads” result in excessive current in the transistor so results in over heating and its final demise after a period of time. Voltage overloads occur instantaneously, blasting a hole in the junction.

What happens when you use transistor in reverse?

Now, if you use the transistor in reverse, the emitter becomes the collector and the collector becomes the emitter, and its quite simple to see what happens: (1). As the collector doping is less than the emitter doping, the hole current in the collector (now the emitter) increases, leading to lower beta.

What happens when I bias the collector and emitter?

The minority carrier electrons recombine in the basis region. (2.) They get attracted by the CB junction, which is biased in reverse direction. However, the minority carrier electrons cross the CB region, become majority carriers in the collector, and form the collector current.

What happens when the NPN transistor is biased?

Let me explain again what the operation of the transistor is: When the NPN transistor is ON, its BE junction is biased in the forward direction. This means now holes from the basis cross the junction, become minority carriers in the emitter, and diffuse to the emitter contact.

Why does the emitter have a low breakdown voltage?

There is one more reason, emitter being heavily doped (acting as collector now) will have a very low breakdown voltage, so you can not operate it at higher voltage level. This has to do with the operation of the transistor. Let me explain again what the operation of the transistor is: