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Definition of Transistors, Transistor Functions And Types of Transistors

Definition of Transistors, Transistor Functions And Types of Transistors

Transistor Functions And Types of Transistors - Transistors are semiconductors with many functions, such as amplifiers, breakers, connectors, voltage stability, and signal modulation. This component is widely used in electronic circuits. 

Almost all electronic devices use transistors as their components. The electronic devices include televisions, computers, mobile phones, audio players, video players, game consoles, power supplies, and amplifiers. 

To better understand it, here is a review of transistors, complete with their functions, types, and how they work. 


Function of Transistors

The transistor's primary roles in an electronic circuit are as an electric current amplifier and a digital switch for the DC motor. At the same time, the three transistor's legs' functions are the following.

While the Emitter is in charge of producing the flow of electrons and the Collector is responsible for directing. 

The flow of electrons out of the transistor, the base controls the movement of electrons from the Emitter coming out of the Collector's tip or foot. The specifics of how a transistor works will be discussed at the point below:

Definition of Transistors, Transistor Functions And Types of Transistors

Amplifier for Electric Current

One of a transistor's functions is strengthening the electric current entering an electronic circuit. The transistor may therefore be included in a power supply circuit.

The current must be refracted with a constant voltage by using a voltage that has been calibrated so that the transistor may be used.


Electronic Switch

One of the devices that may be utilized as a switch is a transistor. By controlling the bias to saturation, the transistor can function as a switch by creating proximity between the connection leg and the Emitter.


Signal Booster for Cell Phones

The primary purpose of transistors in a smartphone is to serve as a signal amplifier for cellular devices. Transistors also store data and electric current in a smartphone's electrical circuit.



How Transistors Work

  • The transistor has four distinct operating modes since it is a non-linear device. Here is the transistor's mode of operation or how it functions:
  • Saturation: When a transistor is saturated, it behaves as a short circuit, and current can easily flow from the Collector to the Emitter.
  • Cut-off: When a transistor is cut off, it behaves like an open circuit, and no current flows from the Collector to the Emitter.
  • Active (Forward-Active): Directly proportional to the current flowing to the base is the current flowing from the Collector to the Emitter.
  • Reverse-Active: In this mode, the current flows opposite to that of the base current, from the Emitter to the Collector.


Categories of Transistors

  1. Transistors may generally be divided into a variety of categories, some of which are shown below:
  2. Depending on the kind, for example, UJT, BJT, JFET, IGBT, IGFET, "MOSFET," HBT, V-MOSFET, MISFET, HEMT, MESFET, etc.
  3. They are based on semiconductor components such as gallium arsenide, silicon, and germanium.
  4. Based on the physical packaging, including IC, metal through-hole, surface mount, plastic through-hole, etc.
  5. According to polarities like PNP or P-channel and NPN or N-channel.
  6. Low, medium and high power are based on the maximum power capacity.
  7. Based on the highest frequency that may be used, which can be low, medium, or high frequency, RF transistor, microwave, and so on.
  8. Depending on applications like audio, general use, high voltage, etc.


Transistor Types and Their Function

Let's speak about the different varieties of transistors if you already know what a transistor is. Bipolar transistors and field-effect transistors are the two basic categories of transistors. There are notable distinctions between these two types of transistors. The input and output biases when using this transistor show this. See the definitions of each of these transistor types for further information.

Transistor Types and Their Function

Transistor Bipolar (Current)

A bipolar transistor controls current terminals. This transistor needs electron and hole charges to function. In other words, intermediates are necessary for charge transfer in these transistors. Therefore, electrons must be at the negative pole to fill the hole on the positive pole side with less charge.


This transistor is typically called a BJT (Bipolar Junction Transistor). The NPN and PNP transistor types still exist in this bipolar transistor. Three terminals cover the base, Collector, and Emitter of each transistor. This clarifies transistors and the many sorts of them that come concerning electronics.


The NPN transistor

Given the type P semiconductor material, which is in between kinds N, space allows for the creation of this structure. This is done to enable a stronger current to pass from the source to the Emitter. So that it may generate a positive current (+), it requires a bit of bias that is positioned on the leg of its base.


The PNP transistor

The reverse of what is said above is true for transistor definition and PNP—obtained by sandwiching a type P semiconductor between two others.


Transistor Field Effect

This transistor, often abbreviated as FET, uses electricity to regulate its conductivity. The electric field here refers to a terminal gate that may handle the current in the drain and source. Because they only utilize one of the charges conveying them, these transistors are also referred to as unipolar. There are three different transistor types in this FET.


Transistor Junction Field Effect (JFET)

By examining the arrow's direction, it is possible to determine this transistor's kind and definition. Because there are two JFET channels—JFET channel N and JFET channel P—in this transistor. JFET channel P leads inward for arrows, whereas JFET channel N leads outward.


Metal Oxide Semiconduction Field-Effect Transistor (MOSFET)

For precision and high current voltage, use a metal oxide semiconductor field-effect transistor (MOSFET). This transistor must be careful since it is slightly sensitive to static electricity. Use a specific solder if necessary to get anti-static properties.


Uni Junction Transistor (UJT) 

is a field-effect transistor (FET) component since it needs an electric field to function. In contrast to the W among them, For its emitter terminals, this type employs the bases B1 and B2. Note that this UJT is not utilized for amplifiers, just controllers.


It would be best to comprehend both the concept of a transistor and its kinds, given the highly significant role of this transistor. Additionally, Also an understanding of how transistors work. Any transistor, bipolar or field-effect, can be employed following its intended usage for the proper operation of electronics.

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