A decoder is a type of digital circuit that converts the language of machine-readable language into user understandable language. 

Decoder

Decoder 


It gets a set of inputs that represent a binary number and activates output corresponding to the binary number. It plays the inverse role of an encoder.
In a decoder, we have to give n input line and from this, we will get a 2n output line.

3 to 8 Line Decoder


In every situation in this table, we see only a single output 1 and others are 0. For 3 line input, we get 8 line output. From 3 to 8 line decoder we get an octal number from a binary number.


Decoder table 


Input
Output
A
B
C
D₀
D₁
D₂
D₃
D₄
D₅
D₆
D₇
0
0
0
1
0
0
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
0
0
1
1
0
0
0
1
0
0
0
0
1
0
0
0
0
0
0
1
0
0
0
1
0
1
0
0
0
0
0
1
0
0
1
1
0
0
0
0
0
0
0
1
0
1
1
1
0
0
0
0
0
0
0
1

We get 8 equations,

D₀ =ĀB̄C̄ 
D₁ =ĀB̄C
D₂ =ĀBC̄
D₃ =ĀBC
D₄ =AB̄C̄
D₅ =AB̄C
D₆ =ABC̄
D₇ =ABC


3 to 8 line decoder block diagram


 


3 to 8 line decoder circuit diagram


3 to 8 line decoder Circuit diagram

Decoder applications


The decoder converts the machine language into human-understandable language. Such as,
  • Binary to decimal
  • BCD code to a decimal number
  • Complex written code to normal language 
  • The decoder used in output devices. Such as the computer monitor