Transistors : Types, Functions, and How They Work

As we know transistors are often found in various electronic circuits, both simple and complex. Transistors are usually made of silicon, gallium, arsenide, and germanium.

Transistors : Types, Functions, and How They Work

Uses of Transistors - Transistors are semiconductor devices that can be used as amplifiers, as circuit breakers and switches, voltage stabilizers, and signal modulators. Generally transistors have 3 terminals (legs), namely Base, Emitter, and Collector.

Transistor type

Bipolar Transistor (BJT) – Bipolar transistor is a transistor that requires the transfer of charge carriers in the form of electrons at the negative pole to fill the lack of electrons at the positive pole. This type of transistor is often referred to as a BJT (Bipolar Junction Transistor).

Transistors are grouped into several types, namely:

NPN Transistor – The electric current possessed by an NPN transistor is relatively small. The positive voltage at the base terminal is used as a voltage controller and the electric current coming from the collector to the emitter is getting bigger.

PNP Transistor – PNP transistor uses a small electric current. The negative voltage at the base terminal is used to control the voltage, and the current from emitter to collector is greater.

Field-Effect Transistor (FET) - This component is also known as Unipolar. There are two types of unipolar transistors namely n channel and p channel. This type of transistor uses electricity to control the level of conductivity. In this case the electric field in question is the electric voltage at terminal G which acts as a voltage regulator and electric current from terminal D to terminal S.

Single Electron Transistor - Single Electron Transistor A single electron transistor is a transistor that can record a signal with one or a small number of electrons. With the development of semiconductor etching technology, large-scale integrated circuit (IC) integration is becoming higher and higher than the previous value.

Isolated Gate Bipolar Transistor (IGBT) - Isolated Gate Bipolar Transistor is a transistor with the advantage of combining Giant Transistor-GTR technology and Power MOSFET.

Insulated Gate Bipolar Transistor Has a flexible character for use in various applications. IGBT also has a three-terminal device, namely gate, collector and emitter.

Giant Transistor (GTR) - The giant transistor or GTR is a special bipolar junction transistor (BJT) for high voltages and high currents. These devices are often referred to as power BJTs. This transistor has good switching characteristics, high driving power, but the drive circuit is complicated.

Functions of transistors in computers and transistor terminals

As a switch - The transistor needs a trigger to allow current to flow and the trigger is at the base. When the base has a minimum current (datasheet) then the emitter-collector leg will work as a switch to close and drain current so that the lamp can turn on.

As a current amplifier - One of the working principles of BJT transistors is that a small current in the base will turn into a large current in the collector. This is because the transistor has an Hfe/gain indicator where each transistor has a different Hfe value.

Suppose the transistor has a Hfe of 100 then the current flowing in the base is 0.6 amperes then the current flowing in the collector is 6 amperes.

As a signal amplifier - An amplifier circuit is a circuit for converting a small signal into a large signal. The signal size is changed by changing the signal amplitude. In the above circuit, the microphone functions to convert sound energy into electrical energy. While earphones or speakers function to convert electrical energy into sound.

How Transistors Work, Transistor Diagram and Transistor Login

Of the many types of modern transistors today, initially there were only 2 basic transistor types, namely the bipolar transistor "BJT or bipolar transistor" and the FET "Field-Effect Transistor" which worked differently.

Bipolar Transistor (BJT) - This transistor carries a bipolar charge because its main conduction channel uses two polarities of charge carriers electrons and holes, to carry electric charge or current. In BJT transistors, the main current must pass through a region or boundary layer that causes depletion, and the thickness of this layer can be adjusted at high speed to regulate the main current flow.

FET "Field Effect Transistor" - FET or unipolar transistor that uses only one type of charge carrier (electron or hole, depending on the type). In a FET transistor, the main current flows in a narrow conduction channel with a side depletion zone. Then the thickness of this boundary region can be changed by changing the applied voltage, to change the thickness of the conduction channel.