What Are the Types of Large-Scale Integrated Circuits?

In today's rapidly evolving electronics industry, large-scale integrated circuits have become the core of modern electronic devices and have penetrated every aspect of our daily lives. From smartphones and personal computers to data centers and industrial control systems, these highly integrated tiny chips carry the critical task of driving the digital world. Understanding the classification of large-scale integrated circuits not only helps us grasp the technological framework of the electronic components industry but also provides insight into the direction of future technological development. This article will systematically outline the various ways large-scale integrated circuits are classified.

Catalog

I. What Are Large-Scale Integrated Circuits?

II. Classification of Large-Scale Integrated Circuits

1. Classification by Functional Structure

2. Classification by Manufacturing Process

3. Classification by Level of Integration

4. Classification by Conduction Type

5. Classification by Usage

6. Classification by Application Field

7. Classification by Physical Form

III. Conclusion

I. What Are Large-Scale Integrated Circuits?

LSI, or Large Scale Integration, generally refers to integrated circuits that contain between 100 and 9,999 logic gates, or 1,000 to 99,999 electronic components, integrating over a thousand elements onto a single chip. An integrated circuit, often abbreviated as IC and known as an accumulation circuit in some regions, is a miniature electronic device or component. Using specific manufacturing processes, all necessary elements in a circuit—such as transistors, diodes, resistors, capacitors, and inductors—are interconnected and fabricated onto one or several small semiconductor wafers or substrate materials, then packaged into a single casing to form a microstructure with the required circuit functions. All components are structurally integrated as a single unit. Integrated circuits are commonly represented by the letters IC, and in some cases by other symbols such as N.

II. Classification of Large-Scale Integrated Circuits

Integrated circuits can be categorized in multiple ways depending on the classification criteria. The following sections explain the classifications based on functional structure, manufacturing process, level of integration, conduction type, usage, application field, and physical form.

1. Classification by Functional Structure

According to their function and structure, integrated circuits are mainly divided into analog ICs, digital ICs, and mixed-signal ICs. Analog ICs are used to generate, amplify, and process continuously varying analog signals, such as audio amplifiers and sensor signal processing circuits, where the input and output signals maintain a proportional relationship. Digital ICs generate, amplify, and process digital signals, which take discrete values in both time and amplitude, such as logic gates, microprocessors, and memory devices. Mixed-signal ICs combine analog and digital circuits to perform functions like analog-to-digital and digital-to-analog conversion and are commonly used in communication systems and data acquisition systems.

2. Classification by Manufacturing Process

Integrated circuits can be classified based on manufacturing process into semiconductor ICs and thin/thick film ICs. Semiconductor ICs are the most common type in modern electronics and are mainly based on silicon and other semiconductor materials, fabricated through photolithography, etching, ion implantation, and other processes. Thin- and thick-film ICs deposit components onto substrates to form resistors, capacitors, and other structures. They were historically used in specific applications but now occupy a much smaller share of the market compared with semiconductor ICs.

3. Classification by Level of Integration

Integrated circuits can be divided into several levels according to the number of components on the chip, including small-scale ICs (SSI), medium-scale ICs (MSI), large-scale ICs (LSI), very-large-scale ICs (VLSI), ultra-large-scale ICs (ULSI), and even larger scales. Small-scale ICs are suitable for basic logic gates or simple functional modules, medium-scale ICs offer higher integration, large-scale ICs can implement more complex logic and memory functions, and very-large and ultra-large-scale ICs are used in high-performance microprocessors and memory chips. These classifications continue to evolve with technological progress but broadly reflect circuit complexity and functional density.

4. Classification by Conduction Type

From the conduction perspective, integrated circuits are classified into bipolar ICs and unipolar ICs, which mainly represent different digital IC manufacturing processes. Bipolar ICs use bipolar transistor technology, which is more complex and consumes more power but offers advantages in high-speed and high-frequency applications, with typical examples including TTL and ECL series. Unipolar ICs use field-effect transistor technology, which is simpler, consumes less power, and is the most common type in large-scale ICs, including CMOS, NMOS, and PMOS.

5. Classification by Usage

Classification by usage categorizes ICs according to their function in specific devices or systems. ICs can be designed for various purposes, including television ICs, audio ICs, DVD player ICs, VCR ICs, computer ICs, and communication ICs. Each type can be further divided into specific functional modules. For instance, television ICs may include scanning control circuits, color decoding circuits, and switch-mode power control circuits. This classification helps designers and purchasers select appropriate chips for specific application scenarios.

6. Classification by Application Field

From the application field perspective, ICs can be divided into standard general-purpose ICs and application-specific ICs. Standard ICs are basic chip components usable in a variety of electronic systems, such as universal logic gates and standard memory devices. Application-specific ICs are custom-designed for particular systems or uses and feature circuit characteristics that only function within their intended application, such as chips for specific communication protocols or custom processors. This classification is valuable for product development and industry market analysis.

7. Classification by Physical Form

IC physical form classifications describe packaging types, which suit different application needs. Common forms include round metal can packages, flat packages, and dual in-line packages (DIP). Round metal can packages provide better thermal performance and are suitable for high-power applications. Flat packages are small, stable, and ideal for surface-mount and compact designs. Dual in-line packages are traditional through-hole packages suitable for general-purpose circuit boards.

III. Conclusion

In summary, the diversified classification system of large-scale integrated circuits provides a clear picture of their technical characteristics and industrial ecosystem. From the functional distinction between analog and digital signal processing to the nanometer-scale manufacturing competition, and from customized applications for numerous industries, each type of IC advances technology within its domain. Currently, IC development has surpassed the large-scale phase, entering the era of ultra-large and gigantic-scale integration, with continuous progress toward 2-nanometer and more advanced process nodes. Meanwhile, advanced packaging and system integration technologies, such as Chiplet architecture, 3D integration, and silicon photonics, are breaking traditional classification boundaries and reshaping chip design and manufacturing paradigms.