Encoder and Decoder

 What is an encoder?
An encoder is a device that converts a physical signal into a digital signal.

The encoder is also a combinational logic circuit; it converts information, such as a
decimal number or an alphabetic character, into some coded form such as binary or BCD.

Encoders are used in a variety of applications, such as robotics, industrial control, and
telecommunications.

An encoder accepts digit on its inputs, such as a decimal or octal digit, and converts it
to a coded output, such as a binary or BCD. Encoder can also be devised to encode
various symbol and alphabetic characters. This process of converting from familiar
symbols or numbers to a coded format is called encoding

 Types of encoders: There are many different types of encoders, including:
 Optical encoders: Optical encoders use light to detect changes in position or rotation.
 Magnetic encoders: Magnetic encoders use magnetic fields to detect changes in position or rotation.
 Inductive encoders: Inductive encoders use eddy currents to detect changes in position or rotation.

 How encoders work:

Encoders typically work by detecting changes in position or rotation and converting
these changes into a digital signal.
The digital signal can then be used to control a motor, robot, or other device.

What is a decoder?
A decoder is a device, circuit, or program that converts an analogue signal into digital data.
• It is Multiple Input & Multiple Output device.
• Decoder is a combinational circuit that converts n lines of input into maximum 2^n lines
of output.
• Applications of decoders are converting binary code to other codes like:
• Binary to octal
• Binary to Hexadecimal
• Binary to decimal
 Types of decoders:
1. Audio decoders: These decoders convert compressed audio files, such as MP3s, back to
their original WAV format.
2. Image decoders: These decoders convert compressed image files, such as JPEGs and
PNGs, back to their original bitmap format.
3. Text decoders: These decoders convert encoded text, back to its original form.
4. Video decoders : These decoders convert compressed video files , such as mp4s, back
to their original Bitmap format.

5. How decoders work:
Decoders typically work by converting a digital signal into a physical signal.
The physical signal can then be used to control a motor, robot, or other device.

About Decoder Circuit
The arrangement ensures that each output line is activated when the corresponding input
combination is detected. When an input line is low (0), its complement becomes high (1),
and the corresponding AND gate outputs a low signal (0) regardless of the other input. As a
result, only one output line is activated at a time, based on the input combination.
Decoders are used for code conversions and used to convert an analogue signal into digital data, which can
be processed by a computer. Decoders are essential components in various fields including computer
science, electronics, telecommunications and information technology. Here are some of the common uses of
decoders in different contexts:

 DIGITAL ELECTRONICS:
 Memory Systems: Decoders are used to select a specific memory location RAM (Random
Access Memory) or ROM (Read-Only Memory) based on the address lines.
 Display Systems: In applications like 7-segment displays, decoders convert binary information into a format that can be displayed on the screen.
 Data Multiplexing: Decoders are used to demultiplex data from one source to multiple output lines.
 Address Decoding: Decoders help select a specific device or registers in a computer’s memory
or (Input / Output) system.
 COMMUNICATION SYSTEMS:
 Error Detection and Correction: In communication systems, decoders are used in errordetecting and error-correcting codes.
 Digital Signal Processing: Decoders are used to convert digital signals from one format to another in various signal processing applications.
 TELECOMMUNICATIONS:
 Digital Television: Decoders are used in set-top boxes to convert digital signals into analog or high
definition signals for television display.
 Mobile Communication: Decoders are used in mobile phones to decode audio and video signals for playback.
 Fax Machines and Modems: Decoders are used to interpret signals received from fax machines or modems.
 COMPUTER PROGRAMMING AND SOFTWARE:
 File Compression: Decoders are used to decompress compressed files. For instance in applications like ZIP files, decoders are employed to extract the original files.
 Encoding and Decoding Data: Decoders play a crucial role in encryption and decryption
algorithms, ensuring secure communication over the internet.
 Media Codecs: Decoders are used in media players to decode audio and video files into formats that
can be played back and displayed on a computer or mobile device.
 AUTOMOTIVE INDUSTRY:
 In-Car Entertainment Systems: Decoders are used in multimedia systems within cars to decode
audio and video signals for entertainment purposes.
 Engine Control Units: Decoders are utilized in the electronic control units of modern vehicles to
interpret sensor data and make necessary adjustments to engine performance.
 ROBOTICS AND AUTOMATION:
 Sensor Data Interpretation: Decoders help interpret signals from sensors, enabling robots to react
their environment effectively.
 Control Systems: Decoders are used in control systems to interpret digital signals and control
various actuators and devices.