In this note, we are going to explain the difference between Analog and Digital Signals. This note can also be download as PDF. Welcome to Poly Notes Hub, a leading destination for diploma or polytechnic engineering notes.
Author Name: Arun Paul.
Explain the Difference Between Analog and Digital Signals
Before going into the difference between analogue and digital signal, we have to know about Analog Signal and Digital signals and their features. Below, we write down the definition of an analogue signal and a Digital Signal. Also, you can download the PDF of this note easily by clicking on the printer icon below.
What is Analog Signal?
An analog signal is one that varies continuously throughout time. It can accept any value within a specified range. Analog signals accurately reflect genuine physical quantities such as sound, temperature, and light.
Definition of Analog System
An analog system is one that operates with continuous signals. In this system, input, output, and processing all take the form of continuously altering values such as voltage, current, sound, and temperature.
Features of Analog Signal
- Continuous in nature (time and amplitude).
- Can take infinite values between minimum and maximum.
- More accurate for representing real-world data.
- Highly sensitive to noise and distortion.
- Requires analog components like resistors, capacitors, inductors, op-amps.
- Difficult to store and transmit over long distances without loss.
Examples of Analog Signals
- Human voice in air
- Sound waves from a microphone
- Temperature measured by analog thermometer
- Light intensity variations
- Radio waves
- Heartbeat ECG signal
Examples of Analog Systems
- Radio receivers
- Audio amplifiers
- Analog watches
- Analog thermometers
- Old television systems
- Microphone and speaker systems
What is Digital Signal?
A digital signal is a type of signal with discrete values, typically represented in binary (0 and 1). Digital signals do not vary gradually; rather, they shift in stages.
Definition of Digital System
A digital system is one that works with discrete signals, typically in the form of binary values (0 and 1). These systems use digital circuits for processing, control, calculation, and communication.
Digital systems are employed in practically all current electronic equipment because of their dependability, speed, and ease of data storage.
Features of Digital Signal
- Discrete in nature, not continuous.
- Takes only finite values, commonly 0 and 1.
- Less sensitive to noise, highly reliable.
- Easy to process, store, compress, and transmit.
- Uses digital components like logic gates, flip-flops, microprocessors.
- Suitable for computers, communication systems, and modern electronics.
Examples of Digital Signals
- Data in computers (0s and 1s)
- Digital clock signals
- Output from digital sensors
- Digital audio (MP3), digital video
- Signals in smartphones and laptops
- Binary data used in communication systems
Examples of Digital Systems
- Computers and laptops
- Smartphones
- Digital calculators
- Digital Camera
- Digital watches
- Microcontrollers and microprocessors
- Digital communication systems
Analog Signal Vs Digital Signal
Here we have added a table from which you can know the differences between analog and digital signals –
| Analog Signal | Digital Signal |
|---|---|
| Continuous signal that varies smoothly over time | Discrete signal that changes in steps |
| Takes infinite values within a range | Takes finite values, usually 0 and 1 |
| Highly sensitive to noise, easily distorted | Less sensitive to noise, more reliable |
| Harder to store and transmit without loss | Easy to store, process, compress, and transmit |
| Represented as sine waves | Represented as square waves |
| Requires analog components like resistors, capacitors, op-amps | Uses digital components like logic gates, flip-flops, microprocessors |
| Provides more natural and accurate representation of physical signals | Provides reliable processing but not naturally continuous |
| Used in microphones, radios, analog TVs | Used in computers, digital clocks, smartphones |
Differences Between Analog System and Digital Logic System
| Feature | Analog Logic System | Digital Logic System |
|---|---|---|
| Signal Type | Continuous | Discrete (Binary) |
| Values | Infinite values | Two values (0,1) |
| Accuracy | High | Moderate |
| Noise | Highly affected | Less affected |
| Circuit Complexity | Complex in precision | Simpler & scalable |
| Cost | Higher for precision | Lower & scalable |
| Speed | Sometimes faster | Very fast with high frequency |
| Storage | Hard | Easy |
| Example Devices | Radio, analog thermometer | Computer, digital clock |