What are Analog and Digital Signals? Differences, Examples

The basic difference between analog and digital signals is that an analog signal is a continuous signal whereas a digital signal is a discrete signal.

What is a Signal?

The signal is a term that comes from the Latin “signalis”. A signal is a noticeable modification of the environment produced to communicate. We can use any type of external stimulus as signals such as linguistic expressions, gestures, drawings, and clicks, among others.

A signal can also be the variation of an electric current or another physical magnitude that is used to transmit information. In other words, a signal is nothing else than a variation of voltage over time. As time changes, the signal changes, which means voltage changes.

Types of Electrical signals

  • Analog signal
  • Digital signal

This article discusses the difference between analog and digital signals.

Analog and digital signals

When an electronic device shows us information, it can do it analogically or digitally.

Analog means that the information, the signal, to pass from one value to another passes through all the intermediate values, it is continuous.

On the other hand, digital signals jump from one value to another without taking intermediate values into account. 

An analog signal is continuous and can take infinite values.

A digital signal is discontinuous, and can only take two values or states: 0 and 1, which can be low and high voltage electrical impulses, open or closed switches, etc.

Analog and digital systems

A digital system and analog systems refer to the two different of electronic circuits.

A Digital system is any system that can generate, process, transmit, or store signals using digits and that only supports discrete values, that is, it only supports a limited set of numbers or values.

An Analog system is the system whose signals are represented with continuous values, that is, which admits infinite numbers or values.

Compared with analog systems, digital systems are more precise and store more efficiently and in greater quantities than analog systems.

Analog and digital signals are different types that are mainly used to transport data from one device to another.

Analog The signals are continuous wave signals that change with the period of time while digital is a discreet signal in nature.

The main difference between analog and digital signals is, that analog signals are shown with sinusoidal waves while digital signals are shown with square waves.

Analog signals have several advantages over digital signals.

Digital signals are safer and do not get affected by noise.

Microcontrollers are usually digital beasts, but their internal circuitry is frequently capable of interfacing with analog circuitry. An analog-to-digital converter (ADC) allows a micro-controller to connect an analog sensor to read voltage.

Let us discuss some dissimilarities between analog and digital signals.

The best example of analog and digital is that of electrons because it deals with analog and digital signals, inputs, and outputs. In a way, an electronic project interacts mainly with the actual analog world while digital signals with computers, microprocessors, and logical units.

These are two types of signals are similar to different electronic languages. Like some of the other languages can only recognize and speak only one of them. 

What are analog and digital signals?

Analog Signals

It is a type of time-varying continuous signal that is divided into composite and simple signals.

Analog signals are generally sine waves, which cannot be decomposed. On the other hand, a composite type of analog signal can be decomposed into many sine waves.

An analog signal can be defined using amplitude, time period if not frequency, and phase. Amplitude streaks the highest pitch of the signal, Frequency streaks the rate at which an analog signal varies, and Phase streaks the position of the signal relative to time nothing.

An analog signal is not noise resistant, so it faces distortion and reduces the transmission quality. It is not possible to fix the range of analog signal values.

Examples of analog signals

  • Audio signal
  • Video signal
  • Radio signal

Digital signal

Similar to analog signals, digital signals carry data although it is a bit different. These signals are discrete or non-continuous.

A digital signal carries data in the form of binary as it means in bits. Also, these signals can be broken down into sine waves called harmonics.

Like analog signals, digital signals have amplitude and frequency, and phase. We can define the digital signal by bit interval as well as by bit rate. Here, bit interval is nothing but the time required to transmit a single bit, while bit rate is the frequency of bit interval.

Digital signals are more resistant to noise, therefore, they hardly face any distortion. These waves are simple to transmit and more reliable, unlike analog waves. Digital signals include a limited variety of values between 0 and 1. 

Examples of digital signals

  • Transmitters functions on pulse width modulation
  • Digital watches.
  • Digital video signals.
  • Devices like CD’s, DVD’s
  • Computer
  • Printer

Difference between Analog and Digital Signals

Analog signalsDigital Signals
It is a continuous & time-varying signal.It has only two states. It has binary states 0 & 1.
An analog signal is usually in the form of a sine wave. However, it may be also in the form of triangular, sawtooth, or any time-varying form.A Digital signal is usually in the form of a square wave that represents two states of the signal.
It is difficult to troubleshoot the analog circuit.It is easy to troubleshoot digital circuits.
They are sensitive to noise. The analog signal can catch the noise signal.Digital signals are not prone to noise.
The noise can affect the accuracy of the analog signals.The noise can not affect the accuracy of the analog signals.
Analog signals may pick the noise during signal transmission.The Digital signal does not pick up the noise during signal transmission.
Analog signals use more power.Digital signals are less powerful.
Examples of the analog signal are temperature, pressure, flow measurements, etc.Examples of digital signals are valve feedback, Motor Start, Trip, etc.
Major components of the analog circuits are resistors, Capacitors, Inductors, Diodes Major components of the digital circuits are ICs, Microcontrollers, etc.

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