An encoder is a device or circuit that converts information from one format to another, typically taking multiple input signals and producing a smaller number of coded output bits, like turning a decimal number into its binary equivalent or converting mechanical motion into digital signals for a computer. Its main job is to efficiently represent data for processing, storage, or transmission, often by compressing or transforming it into a machine-readable code, acting as the reverse of a decoder.

How it works

• Input/Output: An encoder has 2n2 to the n-th power
• Conversion: When one of the input lines is activated
• Logic: It uses combinational logic (often OR gates) to map specific input combinations to unique binary codes. 

Types and examples

• Digital Electronics:

  Converts decimal, octal, or hexadecimal inputs into binary (e.g., a 10-to-4 decimal-to-BCD encoder). 

• Motion Control:

  Converts mechanical motion (like shaft rotation) into electrical signals, used for position and speed feedback in motors. 

• Data/Signal Processing:

  Compresses data or converts analog signals to digital for efficient transmission (e.g., text to ASCII/UTF-8). 

Key functions

• Data Compression: Reduces the number of bits needed to represent data. 

• Efficient Communication: Enables different parts of a digital system to communicate effectively. 

• Data Conversion: Transforms data into a format suitable for processing or storage.