Hello Friends. In this article, I will tell you about what are semiconductor transistors? What are their types and application? So without wasting any time lets start our article.
What are Semiconductor Transistor?
Transistors are small and complex semiconductor devices that are designed to amplify or switch electronic power and signals. If we look around at devices in daily life almost every one of them has a transistor. Some of them are packged individually while some are in intrigued circuits. The transistors are one of essentials in today’s century.
Transistors are the simultaneous connection of two diodes. It provides a passage o current and voltage for electronic signals. There are three terminals in transistors named emitter, base, and collector respectively.
Working Principle of Transistor
A transistor works on an operating system that allows it to control the follow of current/voltage through a path with varying the intensity of current through the second path.
Types of Transistors
There are different types of transistors and they are classified based on their applications. The following are important types of transistors:
1. Bipolar Junction Transistor
There are three main parts of Bipolar Junction Transistors i.e. base, collector, and emitter. Bipolar transistors are mainly current-controlled devices. The current flows from the emitter to the collector and it results in a heavy flow of current from the base towards the emitter.
Bipolar Junction Transistors are further classified into types and they are as follows:
1.PNP Transistor
P-type semiconductors represent the emitter and collector while they are being dropped by the N-type semiconductor, which shows the base. In the depletion region at both junctions, they move towards the N-type layer. The majority charges are holes and electrons are in minority. The structure of the PNP type is illustrated by the diagram:
Working Principle of P-N-P Transistor
The current is being created at the emitter when the emitter-base junction is forward biased. As a result of which the emitter pushes the holes in the base region. The holes are created when the electrons move towards the N-type semiconductors. The base as compared to others is dope and thin. As a result of which only a few electrons are combined with holes. The rest of the few holes move towards the collector layer. In this way base current is being produced. This current is carried by the holes in the P-N-P transistors. The following is the circuit diagram of the p-n-transistor.
2. NPN Transistor
In this type of Bipolar Junction Transistor, the P-type semiconductor is between the N-type semiconductor. It also has three terminals base, collector, and emitter. There are two diodes back to back and the diode is between the emitter-base and is called as the emitter-base diode. And the diode between the collector base is called the collector base diode.
Working Principle of NPN Transistor
In the NPN transistor, when the current is forward biased then a small voltage (VBE) is observed at the emitter-base junction. And in the case of reverse biased then VCE voltage is observed. There is the emission of charge carriers in the emitter that move towards the base. The base is slightly dope which results in an electron-hole combination in a small amount. There is a presence of electrons in the collector region. The base of the NPN transistor is lightly doped as a result of which there are fewer electron combinations. So the rest of the current is called the base currency. When the collector region is reverse biased then there is force (greater) on the electrons that are moved towards the collector junction and it ultimately results in the attraction of electrons in the collector region.
2. Field-Effect Transistor
In this type of transistor there are three regions named gate, source, and drain respectively. Field-effect transistors are also known as voltage-controlled transistors and are different from bipolar ones. At the gate of the transistor, voltage is applied which controls the current from source to drain.
These types of transistors are known for high input impedances and due to this they only gain less current. That current is inversely effects the resistance of circuit. Due to this phenomena there is less current form the power source of the circuit. FET is further classified into two types. Following are explained briefly:
1.Junction Field-Effect Transistor
They have the resistor, amplifier and switches. This type of transistor does not need any biasing current as they are voltage controlled. The current is flowd from the drain and the source and it all are conterolled by the voltage that is apllied between the source and the gate. Foolowing diagram illustrate the JFE transistor:
2.Metal Oxide Semiconductor Field-Effect Transistor
This transistor is most commonly used. It has source, drain, gate and substrate or the body of four terminals of transistor. It has multiple advantages as it has high impedence and low o/p impedence. They are further classified as N- channel and P-channel type.
Types of some other Transistor
Following are some names of transistors:
1.Multiple-Emitter Transistor
In this type of transistor the emitter is used along with the input signals. Thay have the ability in reducing the power consumption and switching timing.
2. Diffusion Transistor
They are type of Bipolar Junction Transistor. They are created by the dopant diffusion into the semiconductor substarte.
3.Avalanche Transistor
It is a type of Bipolar Junction Transistor that helps in processing of collector-current/collector to emitter voltage area and that is above the voltage of the collector to emitter breakage. It is known as the avalanche breakdown voltage.
4.Schottky Transistor
They are being integrated by the Schottky diode.
5. Darlington Transistor
They have two types of transistors in it. And they are capable of gaining alot of current.
6. Heterojunction Bipolar Transistor
As the name shows they are type of bipolar junction of the transistor analogy, They use high-frequency analogue or digital microwaves.
Conclusion
So dear friends I have tried my best to make you understand the transistors and their type. Hope you enjoy reading.
