Working of BJT Amplifier Circuit
BJT amplifiers are essential in many different applications. There are three primary zones in which Bipolar Junction Transistors (BJT) can be operated. Saturation, Active, and Cut-off regions are those. BJT must function in the active or linear areas in order to function as an amplifier. We shall employ the appropriate BJT amplifiers in accordance with the need.
Therefore, after learning about and comprehending the operation of BJT amplifiers, it is simple to comprehend the operation of JFET amplifiers and MOSFET amplifiers. This article will go over the various types and functions of the BJT amplifier.
Circuit Diagram
If we considered the circuit input signal is given and then its respected output is out of phase. The signal is amplify in the BJT uses a technique known as current amplification to amplify signals. There are three layers in it: base, collector, and emitter. The base is narrow and mildly doped, the emitter is substantially doped, and the collector is moderately doped. Electrons (or holes in PNP) flow from the emitter to the base of the base-emitter junction when voltage is supplied, causing the junction to become forward-biased. The majority of electrons don’t recombine and proceed to the collector because of the thinness and light doping of the base. Signal amplification occurs when this movement produces an output current at the collector circuit that is greater than the input current at the base circuit.
In Common emitter configuration (NPN)
According to the kirchhoff Current law.
IE = IC + IB
Input A.C signal phase -> 0 degree.
Output generated signal phase -> 180 degree.
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