A system is defined as a group of various components interconnected together to perform a specific task. For example, a digital computer consists of several components such as monitor, CPU (Central Processing Unit), memory, keyboard, mouse, printer, and more. All these components are connected together to accomplish certain tasks. Hence, a computer can be termed as a system.

We can broadly classify systems into the following two categories −

• Analog Systems
• Digital Systems

An analog system is a type of system that operates on continuous time signals, while a digital system is one that can work on discrete time signals.

Read this chapter to learn the basics of digital systems and their types.

What is a Digital System?

A type of electronic system that is designed to store, manipulate, and communicate digitally represented information is termed as a digital system. Some common examples of digital systems include smartphone, laptops, smartwatch, tablet, desktop computers, etc.

The working of a digital system is entirely based on digital signals or binary signals. Where, a digital signal is a type of signal that is represented as a discrete-elements. It can have two possible states namely high or low. The high state is denoted by the logic 1 and the low state is denoted by the logic 0.

In a digital system, if the state of the signal is logic 1, the system will be on, and if the state of the signal is 0, the system will be off.

Characteristics of Digital Systems

Today, digital systems are widely used in almost every aspect of life. This is because of their high reliability and efficiency. The following are some key characteristics of digital systems −

• Digital systems are relative less complex to implement as they use binary number system having only two digits to represent the state of a system.
• In digital systems, the information is represented in the form of a group of 0s and 1s i.e., bits. This is called binary or digital representation of information.
• Digital systems rely on digital signals having two well-defined discrete states. This makes digital systems more reliable and efficient in terms of processing, storage, and communication of information.
• Digital systems use logical mathematics and operations to perform computing tasks.
• Digital systems can be manufactured in the form of integrated circuits (ICs) of very small sizes.
• Digital systems can be easily programmed to perform repeated tasks that reduces human efforts and cost.
• Digital systems are highly immune to noise and distortions.

Types of Digital Systems

Digital systems can be classified based on various parameters. Here are some important types of digital systems that we commonly use in practice −

Combinational Digital Systems

A combinational logic circuit or system is a type of digital circuit that performs logical operations and produces output depending on the present inputs. Hence, the output of a combinational digital circuit does not depend on the past inputs and outputs of the system.

Example − The common examples of combinational digital systems are binary adders, subtractors, logic gates, multiplexers, demultiplexers, etc.

Sequential Digital Systems

A type of digital system that has a memory element to store past history of the system operation is called a sequential digital system. Therefore, the output of a digital system depends on both present inputs and past outputs of the system.

Example of sequential digital systems are flip-flops, registers, memory devices, counters, etc.

Programmable Logic Devices (PLDs)

A programmable logic device is one that can be programmed to perform a specific task automatically.

Example of programmable logic devices are microcontrollers, PLCs, etc.

Digital Communication Systems

A digital communication system is a type of digital system used for transmission and reception of information in the form of digital signals.

Example of digital communication systems are internet, intranet, mobile communication system, Wi-Fi, etc.

Digital Control Systems

A digital control system is a computerized control system used to monitor and regulate the behavior of a dynamic system.

Example − Digital control systems are extensively used in robotics, industrial automation, etc.

Conclusion

In conclusion, digital systems are modern systems known for their high speed and reliability. A digital system utilizes digital signals to store, process, and communicate the information.

In this chapter, we explained the basics of digital systems and their types. Traverse to the next chapter to learn all about the types of signals used in the field of electronics engineering.