What is a bipolar transistor?
The bipolar transistor is a electronic device made of semiconductor material, consisting of three regions (EMITTER, BASE, COLLECTOR) separated by two junctions pn. Depending on the type of regions, bipolar transistors are divided into two categories: NPN and PNP.
NPN and PNP type bipolar transistor
NPN type bipolar transistor consists of two N regions separated by a P region. The PNP type bipolar transistor consists of two P regions separated by an N region. The base region is thinner and less doped compared to the emitter region (strongly doped) and the collector region (moderately doped).
A junction is formed between two neighboring regions. Between the base and the emitter is the base-emitter junction, and between the base and the collector is the base-collector junction. Each region has attached a terminal that is marked with E (emitter), B (base), C (collector).
- The structure and symbol of the bipolar transistor
- Encapsulation of transistors and identification of terminals
- Bipolar transistor operation
- Parameters and characteristics of the bipolar transistor
- Bipolar transistor functions
For the better understanding the use and functionality of bipolar transistors, I have attached the following video material: