Working Principle of BJT Amplifiers
An active region that is biased is the NPN transistor. In this case, the collector-base junction is reverse biased while the base-emitter junction is forward biased. Therefore, as compared to the collector-base junction’s width, the base-emitter junction’s depletion region’s width is less. By lowering the barrier potential and facilitating the flow of current from the emitter to the base, the forward biased BE junction will aid.
NPN transistor bases often have fewer holes than the electrons in the emitter because they are narrow and mildly doped. The base current flows as a result of holes in the base recombining with electrons in the emitter region. Typically, the electrons’ direction
The emitter current is equal to the total of the base current and collector current, as stated by Kirchhoff’s Current Law. In general, the emitter current (IE) and collector current (IC) will always be greater than the base current (IB).
IE = IC + IB
BJT Amplifier
Bipolar Junction Transistors (BJTs) have a long and diverse history of use in the electronics industry. They are used as a switching mechanism and for amplification in a wide range of applications. BJTs are highly sought after in power electronics because of their low turn on/off times, low voltage drop, high power, voltage, and current ratings, as well as their little leakage current when in blocking mode. In power electronics, they are mostly used for switching applications. The biasing conditions of the junctions dictate the three different modes of operation that bipolar junction transistors (BJTs) display: cut-off, active, and saturation.
A semiconductor device with three layers and three terminals that alternate between p-type and n-type layers is called a bipolar junction transistor (BJT). Three terminals in the BJT is the Collector, Base, Emitter. The arrangement of their layers distinguishes NPN and PNP, the two varieties of BJTs. The base of an NPN BJT is built of p-type material, whereas the emitter and collector are made of n-type material. On the other hand, the base of a PNP BJT is constructed of n-type material, while the emitter and collector are composed of p-type material. The collector-base junction (CBJ) and base-emitter junction (BEJ) are the two junctions found in a BJT.
Table of Content
- What is BJT Amplifier?
- Working Principle
- Types
- Characteristics
- BJT Amplifier Formula
- DC Analysis of BJT Amplifier Circuits
- Advantages and Disadvantages of BJT Amplifier
- Application of BJT amplifier