Bipolar Junction Transistor (BJT)

A Bipolar Junction Transistor (BJT) is a type of transistor that uses both electron and hole charge carriers. It's a semiconductor device that can amplify or switch electrical signals. A BJT consists of three regions:

1. Emitter (E):

Heavily doped, it emits carriers (electrons or holes) into the base.

2. Base (B):

Thin and lightly doped, it controls the flow of carriers.

3. Collector (C):

Moderately doped, it collects carriers from the emitter via the base.


There are two types of BJTs:

- NPN: The current flows from the collector to the emitter when a positive voltage is applied to the base.

- PNP: The current flows from the emitter to the collector when a negative voltage is applied to the base.


BJTs are widely used in amplifying signals, switching, and as building blocks in various electronic circuits.

Comments