A decoder is a logic circuit that takes a binary input and activates only one of multiple outputs based on the input value. If a decoder has an n-bit input, it will have 2^n outputs. The decoder's truth table shows the logic function that maps each input combination to activate the correct output. The circuit diagram implements this logic function using gates.

1. GREEN UNIVERSITY OF
BANGLADESH
Department: EEE (Eve)
Prepared For:
Chayan Mondal
Lecturer, GUB
Prepared By:
Md. Sahed Dewan
ID# 143010021
Course Title: Digital Electronics

2. Decoder
X0
X1
D0
D1
D2
D3
Decoder

3. A Decoder is a logic circuit that accepts a set
of inputs that represents a binary number and
activates only the output that corresponds to
the input number.
What is Decoder
If a Decoder has n bits input data then the
output data will be 2n bits.

4. X0
X1
D0
D1
D2
D3
D
E
C
O
D
E
R
n = 2
2n = 4
X0
X1
D0
D3
D6
D7
D
E
C
O
D
E
RX2
D1
D2
D5
D4
n = 3
2n = 8
Block Diagram

5. Decimal
Digit
Inputs Logic
Function
Outputs
X2 X1 X0 D0 D1 D2 D3 D4 D5 D6 D7
0 0 0 0 X2 X1 X0 1 0 0 0 0 0 0 0
1 0 0 1 X2 X1 X0 0 1 0 0 0 0 0 0
2 0 1 0 X2 X1 X0 0 0 1 0 0 0 0 0
3 0 1 1 X2 X1 X0 0 0 0 1 0 0 0 0
4 1 0 0 X2 X1 X0 0 0 0 0 1 0 0 0
5 1 0 1 X2 X1 X0 0 0 0 0 0 1 0 0
6 1 1 0 X2 X1 X0 0 0 0 0 0 0 1 0
7 1 1 1 X2 X1 X0 0 0 0 0 0 0 0 1
Truth Table

6. Circuit Diagram
X2
X1
X0
D0D1D2D3D4D5D7 D6

7. Thank you