The multiplexer is a combinational logic circuit designed to switch one of several input lines to a single common output line

1. Balochistan
University Of
Information
Technology
Engineering and
Management
Sciences
Department of
Computer Engineering
Two Channels Multiplexer
or 2x1 Multiplexer
Atta Ullah Khan
43878@student.buitms.edu.pk
DIGITAL SYSTEM DESIGN
#000000

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Overview
 What is Multiplexer?
 Types of Multiplexer.
 Block Diagram of 2x1 and 4x1 Multiplexer.
 Timing Diagram of 2x1 Multiplexer.
 Real Time Multiplexer.
 Example of Two Channels Multiplexer?
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What is Multiplexer ?
 A multiplexer is a device which select one out of several
inputs & forward it to signal Output line.
 Multiplexer is also known as MUX.
 Multiplexer is also known as Data Selector. `
Remember in Multiplexer the number of output is always 1.
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Types of Multiplexer
 02:1 MUX,
 04:1 MUX,
 08:1 MUX,
 16:1 MUX,
 32:1 MUX.
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Block Diagram of Multiplexer
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Block
Diagram of
4 x 1
Multiplexer
Block
Diagram of
2 x 1
Multiplexer
S1
S2
SEL
S1
S2
S3
S4
U
U
SEL1
SEL2
Find Number of Input Lines
n = Selection lines
2n

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Truth Table of 2:1 Multiplexer
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Block
Diagram of
2 x 1
Multiplexer
S1
S2
SEL
U
SEL Output (U)
0 S1
1 S2
Logical Expression / Boolean Function
U = SEL . S1 + SEL . S2

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Timing Diagram of 2:1 Multiplexer
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Truth Table of 4:1 Multiplexer
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SEL1 SEL2 Output (U)
0 0 S1
0 1 S2
1 0 S3
1 1 S4
Logical Expression / Boolean Function
SOP = SEL1 . SEL2 . S1 + SEL1 . SEL2 . S2 + SEL1 . SEL2 . S3 + SE1 . SEL2 . S4
Block
Diagram of
4 x 1
Multiplexer
S1
S2
S3
S4
U
SEL1
SEL2

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Price: 30 Rs
8-Channel Analog
Multiplexer CD4051
Real Time Multiplexer
Price: 80 Rs
8 channel CMOS
Analog Multiplexer
DG408DY

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Circuit Diagram of 2:1 Multiplexer
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U = SEL · S1 · S2 + SEL · S1 · S2 + SEL · S1 · S2 + SEL · S1 · S2
U = (S1 · S2 + S1 · S2) · SEL + (S1 · S2 + S1 · S2) · SEL
U = ((S2 + S2) · S1) · SEL + ((S1 + S1) · S2) · SEL
U = S1 · SEL + S2 · SEL
Minimizing the Circuit
(S1 + S1) = 1,
(S2 + S2) = 1

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Circuit Diagram of 2:1 Multiplexer
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U = S1 · SEL + S2 · SEL
The Final Expression

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Implementation of 4:1 Multiplexer
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https://circuitdigest.com/tutorial/what-is-multiplexer-circuit-and-how-it-works

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MUX – Online Simulator
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Thank You
Have a Nice Day