For faster action which transistor is used and why.

Introduction

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. There are two types of transistors in general use today: the Bipolar Junction Transistor (BJT) and the Field Effect Transistor (FET).

Bipolar Junction Transistors (BJT)

The BJT is a type of transistor that uses both electron and hole charge carriers. In a BJT, the emitter region is heavily doped, the base region is lightly doped and the collector region is moderately doped. The main current flow in a BJT is due to the diffusion of charge carriers across a junction between two regions of different charge concentrations. The mode of operation of a BJT is determined by the junction biasing voltage and the input current.

Technical Properties of BJT

• Low input impedance
• High output impedance
• High gain
• High power dissipation

Field Effect Transistors (FET)

The FET is a type of transistor which uses an electric field to control the flow of current. FETs are devices with three terminals: source, gate, and drain. FETs control the flow of current by the application of a voltage to the gate, which in turn alters the conductivity between the drain and source.

Technical Properties of FET

• High input impedance
• Low output impedance
• Low gain
• Low power dissipation

Comparison of BJT and FET

Why FET is Used for Faster Action

FETs are preferred for faster action due to their high input impedance, low power consumption, and high switching speed.

High Input Impedance

The input impedance of a FET is very high, typically in the order of 10^6 to 10^12 ohms. This is because the input is reverse-biased, and only a very small leakage current can flow. High input impedance means that the FET draws very little input current. This allows the FET to respond more quickly to changes in input voltage, leading to faster action.

Low Power Consumption

FETs have low power consumption, primarily because of their high input impedance. The high input impedance means that very little current is drawn from the power supply. This results in low power consumption, which is a key factor in the speed of electronic devices.

High Switching Speed

FETs have a high switching speed, which is the speed at which a transistor can turn on and off. The high switching speed of FETs is due to the fact that they are majority carrier devices. This means that they do not have a charge storage phase and can respond quickly to changes in voltage.

Examples of Applications Where FET is Used for Faster Action

FETs are used in a variety of applications where speed is important. These include:

• Digital circuits: FETs are used in digital circuits because of their high switching speed and low power consumption.
• Radio frequency amplifiers: FETs are used in radio frequency amplifiers because of their high input impedance, which allows them to amplify weak signals without loading the source.
• Voltage controlled resistors: FETs are used in voltage controlled resistors because of their ability to vary the resistance with the input voltage.

Conclusion

In conclusion, FETs are used for faster action due to their high input impedance, low power consumption, and high switching speed. Understanding the properties of different transistors is crucial in the field of electronics devices and circuits.

Summary

FETs are preferred for faster action due to their high input impedance, low power consumption, and high switching speed. They have a high input impedance, which allows them to respond quickly to changes in input voltage. FETs also have low power consumption, primarily because of their high input impedance. Additionally, FETs have a high switching speed, which is the speed at which a transistor can turn on and off. They are used in various applications such as digital circuits, radio frequency amplifiers, and voltage controlled resistors.

Analogy

Think of FETs as athletes who are quick to react to changes in their environment. They have high input impedance, which is like having sharp senses to detect even the slightest changes. Their low power consumption is similar to athletes who conserve energy to perform at their best. Lastly, their high switching speed is comparable to athletes who can quickly change direction or switch between different actions.