Difference Between Encoder and Decoder
Last Updated :
23 Jul, 2025
Combinational Logic is the concept in which two or more input states define one or more output states. The Encoder and Decoder are combinational logic circuits. In which we implement combinational logic with the help of boolean algebra. To encode something is to convert in piece of information into a form of code that is not so clearly understood and the device which performs this operation is termed as Encoder.
What is Encoder?
An Encoder is a device that converts the active data signal into a coded message format or it is a device that converts analogue signal to digital signals. It is a combinational circuit, that converts binary information in the form of 2N input lines into N output lines which represent N bit code for the input. When an input signal is applied to an encoder the logic circuitry involved within it converts that particular input into coded binary output.
To decode is to perform the reverse operation: converting a code back into an unambiguous form code and the device which performs this operation is termed a Decoder.
Advantages & Disadvantages of Encoder
- Encoders provide highly accurate and repeatable position feedback for precise control in various applications. They can measure the linear and rotary motion with the high resolution enabling exceptional accuracy in the positioning tasks.
- Encoders used in the wide range of industries from themanufacturing and robotics to healthcare and aerospace. Their ability to work in the diverse environments and integrate it with the various control systems makes them versatile for the motion control applications.
- Encoders can be affected by the dust, debris, vibration and electromagnetic interference potentially leading to the measurement errors. This sensitivity may require the additional protective measures or frequent maintenance in the harsh industrial environments.
- High-precision encoders can be expensive, especially for applications requiring extreme accuracy or specialized features. Their integration may increase system complexity, requiring careful calibration and specialized knowledge for proper installation and maintenance
What is Decoder?
A decoder is also a combinational circuit as an encoder but its operation is exactly reverse as that of the encoder. A decoder is a device that generates the original signal as output from the coded input signal and converts n lines of input into 2n lines of output. An AND gate can be used as the basic decoding element because it produces a high output only when all inputs are high.
Advantages & Disadvantages of Decoder
- Decoders efficiently convert encoded information into a more usable format, enabling systems to interpret and process complex data streams. This capability is crucial in applications like digital communications, memory addressing, and signal processing.
- By reducing the number of control lines needed, decoders help simplify circuit designs and reduce overall system complexity. This leads to more compact and efficient hardware implementations, particularly in digital systems and computer architecture.
- Decoders introduce a small delay as they process and convert signals, which can impact system performance in high-speed applications. This delay may become significant in time-critical operations or when cascading multiple decoders.
- As active components, decoders require power to operate, which can contribute to overall system power consumption. In battery-powered or energy-efficient designs, this additional power requirement may be a consideration, especially for large or complex decoding operations.
Importance of Encoders and Decoders
Encoders and decoders are very important tools in how computers handle information. An encoder takes information and changes it into a special format that's easier to send or store. A decoder does the opposite - it takes that special format and turns it back into the original information. Think of them like a secret code. The encoder writes the message in code, and the decoder reads the code to understand the message. This is useful because sometimes the coded version is smaller or safer to send.
For example when you send a picture online, an encoder might make the file smaller so it sends faster. Then, a decoder on the other end turns it back into a picture you can see. Without encoders and decoders, many things we do with computers and phones would be much harder or slower.
Difference Between Encoder and Decoder
Encoder | Decoder |
|---|
Encoder circuit basically converts the applied information signal into a coded digital bit stream. | Decoder performs reverse operation and recovers the original information signal from the coded bits. |
In case of encoder, the applied signal is the active signal input. | Decoder accepts coded binary data as its input. |
The number of inputs accepted by an encoder is 2n. | The number of input accepted by decoder is only n inputs. |
The output lines for an encoder is n. | The output lines of an decoder is 2n. |
The encoder generates coded data bits as its output. | The decoder generates an active output signal in response to the coded data bits. |
The operation performed is simple. | The operation performed is complex. |
The encoder circuit is installed at the transmitting end. | The decoder circuit is installed at the receiving side. |
OR gate is the basic logic element used in it. | AND gate along with NOT gate is the basic logic element used in it. |
It is used in E-mail, video encoders etc. | It is used in Microprocessors, memory chips etc. |
Types of Encoders and Decoders
Linear encoders and decoders are used most often. They change information in a way that keeps the same pattern as the original. If you put in a little, you get a little out. If you put in a lot, you get a lot out.
Nonlinear encoders and decoders are not used as much, but they can do more things. They change information in a way that doesn't follow the same pattern as the original. What comes out might be very different from what goes in, even if the change is small.
Applications of Encoder and Decoder
Applications of Encoders
- Encoders change data into a form that can be sent over long distances. They help phones, computers, and other devices share information across the world by turning messages into special codes that travel easily.
- In robots and machines, encoders turn physical movement into electrical signals. These signals tell the robot or machine its exact position, speed, and direction, helping it move accurately and do its job well.
- Encoders help computers find specific information in their memory quickly. They work like a librarian, turning a request into a code that points directly to where the information is stored.
- Encoders in sensors change real-world measurements into digital signals. This helps measure things like how far something has moved or how fast it's turning, which is useful in many machines and devices.
- In keyboards and other input devices, encoders change our actions (like pressing keys) into a language computers understand. This lets us type, click, and give commands to our devices easily.
Applications of Decoders
- Decoders change computer code into visible numbers, letters, or pictures. They're used in digital clocks, electronic signs, and screens to show information we can read and understand.
- Decoders in devices like TV boxes or internet routers turn incoming signals back into pictures, sound, or data. This is how we can watch TV shows or browse websites sent from far away.
- In computer systems, decoders help find and read the right information from memory. They're like a guide that takes a code and uses it to find and bring back the exact data needed.
- Decoders figure out what different signals mean, like the beeps when you press phone buttons. They turn these signals into instructions that devices can follow or understand.
- In factories and smart homes, decoders help machines understand commands. They turn simple signals into actions, letting us control complex equipment with ease.
Examples of encoders and decoders
1. Encoder: A tool that changes computer numbers into a signal that can be sent. For instance, it might take the numbers that make up a picture on your computer and turn them into a signal that can be sent over the internet.
2. Decoder: A tool that changes a signal back into computer numbers. Following the previous example, it would take the signal sent over the internet and turn it back into numbers that your computer can show as a picture.
3. Binary encoder: A special encoder that uses simple math rules to change 1s and 0s into a signal. It takes the basic computer language (which is just 1s and 0s) and turns it into a signal that can be sent or stored more easily.
4. Binary decoder: A special decoder that uses simple math rules to change a signal back into 1s and 0s. It takes the signal and turns it back into the basic computer language of 1s and 0s that your computer can understand and use.
Conclusion
The Encoders and decoders are essential in the modern technology. The Encoders convert information into the machine friendly codes while the decoders translate these codes back into a usable data. They work behind the scenes in our phones, computers and many other devices. These tools make it possible for the humans and machines to communicate effectively and enabling everything from digital displays to robot control. The encoders and decoders help bridge the gap between the human understanding and machine processing playing the crucial role in world.
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