Types of Integrated Circuits (ICs)

In this article, we will discuss different types of ICs (Integrated Circuits) in electronics. As we know, the integrated circuits (ICs) are one of the crucial parts of all electronic devices and systems. Without ICs, most of the hi tech electronic devices and gadgets that we use would cease to exist.

Integrated circuits made the electronic devices and systems so small that they became an integral part of every field of human life. Therefore, integrated circuits or ICs are entirely responsible for miniaturization of electronic devices and circuits. Before discussing different types of ICs, let us first understand a bit about integrated circuits.

What is an Integrated Circuit?

When several electronic circuit components like transistors, diodes, resistors, capacitors, etc. are fabricated and interconnected on a single chip of semiconductor material (usually silicon or germanium) to form a circuit, it is referred to as an integrated circuit (IC). Since, several components are integrated on a single chip, due to which it named so.

In an IC, the part called die is the heart of the IC. A die is the part of IC made of semiconductor material on which the functional circuit of the IC is fabricated. The components of an IC cannot be disassembled once they are fabricated, which means the circuit in the form of IC always remains integrated in the form of a single unit and hence it cannot be altered.

Types of Integrated Circuits

Integrated circuits can be classified into several types depending on the basis of packaging size, manufacturing techniques, and operating signal type. Therefore, the classifications of ICs on the basis of different characteristics is given below.

Types of Integrated Circuit based on Chip Packaging Size

Based on the chip size, the following types of integrated circuits are present −

• Small Scale Integrated Circuits

• Medium Scale Integrated Circuits

• Large Scale Integrated Circuits

• Very Large Scale Integrated Circuits

• Ultra Large Scale Integrated Circuits

Types of ICs based on Manufacturing Techniques

Based on the manufacturing technology, the following types of integrated circuit are present-

• Thin and Thick Film Integrated Circuits

• Monolithic Integrated Circuits

• Hybrid or Multichip Integrated Circuits

Types of ICs based on Signal Type

Based on the type of operating signal, the following types of integrated circuits are present-

• Analog Integrated Circuits (ICs)

• Digital Integrated Circuits (ICs)

• Mixed Signal Integrated Circuits (ICs)

Now, we will discuss each of these types of integrated circuits in detail.

Small Scale Integrated Circuits

Initially, the IC technology from around 1961 to 1965 was termed as Small Scale Integration (SSI). In the case of SSI, the integrated circuits had only 2 to 10 components (usually transistors) on a single chip.

At present, the integrated circuits having 2 to 100 transistors on a single chip are called small scale integrated circuits. Small scale integrated circuit are generally used to manufacture logic gates ICs and flip-flop circuits.

Medium Scale Integrated Circuits

Medium scale integration (MSI) is the second higher level of manufacturing integrated circuits. In the medium scale integrated circuits typically 100 to 1000 transistors are to be fabricated on a single semiconductor chip.

Medium scale integrated circuits were prominent in the period of 1966 to 1971. The MSI ICs are generally used to manufacture digital circuits like decoders, multiplexers, memory registers, counters, etc.

Large Scale Integrated Circuits

The large scale integration (LSI) technology of IC manufacture was prominent between 1971 and 1979. LSI was the next higher level of components integration on a single chip. In a large scale integrated circuit, thousands of transistors, typically ranging from 1000 to 20000 transistors, are fabricated on a single semiconductor chip.

Large scale integration is primarily used to manufacture ICs of ROM, RAM, processors, etc.

Very Large Scale Integrated Circuits

The very large scale integration (VLSI) technology of IC manufacture was developed between 1971 and 1979. In vary large scale integration, a single chip contains around 20000 to 50000 transistors. The VLSI technology is mainly used to manufacture ICs for microprocessors, RISC processors, microcontrollers, etc.

Ultra Large Scale Integrated Circuits

Ultra Large Scale Integration (ULSI) is the present IC manufacturing technology. In an IC manufactured in ULSI, typically from 50000 to billions of transistors are integrated on a single chip. The ultra large scale integration is used to fabricate circuits of modern advanced microprocessors and microcontrollers.

Thin and Thick File Integrated Circuits

When passive circuit components like R, C, etc. are fabricated on a semiconductor chip, and diodes and transistors are connected separately to form a complement electronic circuit, then it is called thin and thick film integrated circuit.

Therefore, thin and thick film ICs are the combinations of discrete and integrated circuit components. Basically, in these ICs, two fabrication technologies are used as clear from the name, i.e. thin film technology and thick film technology.

In the thin film technology, the passive circuit components such as resistors, capacitors, etc. are fabricated in the form of IC by depositing a layer or film of a conducting material on a ceramic substrate. The electrical properties like resistance or capacitance of these components are controlled by varying the thickness of the film of conducting material.

On the other hand, in the thick film technology, the passive circuit components are fabricated by depositing a film of conducting material on a ceramic substrate by using the silk printing technology. The connections among different components to realize the circuit are made by either conductive or dielectric pastes. Once the printing of the circuit is done, the chip is then fired in a furnace at a high temperature to infuse the circuit on the chip die.

Monolithic Integrated Circuits

When all the active, passive, and discrete components of the circuit are fabricated on a single silicon crystal, it is called a monolithic integrated circuit. Monolithic ICs are the most widely adopted type of IC. However, it suffers from several physical challenges such as limited power rating, high signal noise, poor insulation, etc.

The manufacturing of monolithic ICs is easy, also they are highly reliable in operation

Hybrid or Multichip Integrated Circuits

When two or more individual chips are interconnected in a single package, it is called hybrid or multichip IC. In these ICs, the active circuit components such as diodes, transistors, etc., and the passive circuit components such as resistors, capacitors, etc. are fabricated on the semiconductor chip. These components are then connected together using metallic connections to form the circuit.

The hybrid ICs are efficient in terms of design and technology. Hence, they are used in high-power, typically 5 watts to 50 watts applications where high-performance is desired.

Analog Integrated Circuits

Analog ICs are the integrated circuits design to operate on continuous-time signals. Analog ICs are also known as linear ICs because they have a linear relationship between input and output. Operational amplifiers (Op-Amps) are the fundamental building blocks of analog ICs. These ICs are widely used in amplifiers, timers, voltage regulators, audio filters, and in many other analog circuits.

Digital Integrated Circuits

The integrated circuits designed to operate on discrete-time signals (or digital signals) are referred to as digital integrated circuits. These ICs work in binary system, i.e. they can be either completely ON or completely OFF. Digital IC is one of the most prominent products of the semiconductor industry.

The applications of digital ICs include logic gates, flip-flops, microprocessors, microcontrollers, multiplexers, encoders, decoders, etc.

Mixed Signal Integrated Circuits

The mixed signal integrated circuits (ICs) are designed to operate on both analog and digital signals. The design and manufacturing of mixed signal ICs is very complex because they consist both analog and digital circuits that require different signal levels, power requirements, etc.

Mixed signal ICs are mainly used in applications such as converter circuits (analog to digital converters or digital to analog converters), implementation power management circuits, radio circuits, etc.

Conclusion

This is all about integrated circuits (ICs) and types of integrated circuits. In this tutorial, we covered all the major types of integrated circuits. Integrated circuits or ICs are the heart of modern electronic systems. The use of ICs makes the circuit compact, reliable, and cost effective. Till date, there are several types of ICs (as discussed above) present depending on the application, manufacturing technology, chip size, etc.