A multiplexer is a digital circuit that has multiple inputs and a single output. It selects one of the multiple input lines to pass to its output based on a digital select line. A multiplexer uses select lines to determine which input is passed to the output. Multiplexers come in different sizes depending on the number of inputs and select lines, such as 2-to-1, 4-to-1, and 8-to-1 multiplexers. Multiplexers are used in applications such as data communications, audio/video routing, and implementing digital logic functions.

1. SILVER OAK COLLEGE OF
ENGINEERING AND TECHNOLOGY
TOPIC :-
STUDENT NAME :- SIDDHI SHRIVAS (130770107163)
DIVISON :- COMPUTER – C
GUIDED BY :-MR. BIKAS MUDULI, SOCET

2.  WHAT IS MULTIPLEXER?
o A MULTIPLEXER is a digital circuit that has multiple inputs and a single
output.
o The selection of one of the n inputs is done by the select inputs
o It has one output selected at a time.
o It is also known as DATA SELECTOR.
o A multiplexer has
N data inputs(multiple)
1 output (single)
M select inputs, with 2M
=N
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3.  BLOCK DIAGRAM OF MULTIPLEXER :
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4.  Types:
 2-to-1 (1 select line)
 4-to-1 (2 select lines)
 8-to-1 (3 select lines)
 16-to-1 (4 select lines)
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5.  2-TO-1 (1 SELECT LINES) MULTIPLEXER
Here 2:1 means 2 inputs and 1 output
BLOCK DIAGRAM TRUTH TABLE
S OUTPUT Y
0 D0
1 D1
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6.  The logical level applied to the S input determines which AND gate is
enabled, so that its data input passes through the OR gate to the output.
 The output, Y=D0S’+D1S
 When
 S=0,AND gate 1 is enabled and AND gate 2 is disabled. So, Y=DO
 S=1,AND gate 1 is disabled and AND gate 2 is enabled . So, Y=D1
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7.  4-to-1 (2 select lines) Multiplexer
 4:1 MUX has 4 inputs(D0, D1, D2, D3) & 2 select lines(S0, S1)
BLOCK DIAGRAM TRUTH TABLE
S1 S0 Y
0 0 D0
0 1 D1
1 0 D2
1 1 D3
MUX
D0
D1
D2
D3
Y
S1 S0
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8.  The logical level applied to the S input determines which AND
gate is enabled, so that its data input passes through the OR
gate to the output.
 The output, Y=S1’S0’D0+S1’S0D1+S1SO’D2+S1S0D3
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9.  8-TO-1 (3 SELECT LINES) MULTIPLEXER
 8:1 MUX has 8 inputs(D0, D1, D2, D3, D4, D5, D6, D7) & 3
select lines(S0,S1, S2,)
BLOCK DIAGRAM TRUTH TABLE
S2 S1 S0 Y
0 0 0 D0
0 0 1 D1
0 1 0 D2
0 1 1 D3
1 0 0 D4
1 0 1 D5
1 1 0 D6
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10.  The logical level applied to the S input determines which AND
gate is enabled, so that its data input passes through the OR
gate to the output.
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11.  Uses of Multiplexers
 Used in data communications for several computers to
communicate over 1 line
 Used in radio to select one channel from many
 Used to route data within a computer
 Used for function generation
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12.  APPLICATION OF MULTIPLEXER:
MP3 Player
Docking Station
Laptop
Sound Card
Digital
Satellite
Digital
Cable TV
Surround Sound System
MUX
D0
D1
D2
D3
Y
B A Selected Source
0 0 MP3
0 1 Laptop
1 0 Satellite
1 1 Cable TV
Multiple Sources Single DestinationSelector
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13. Consider an integer ‘m’, which isconstrained by the following relation:
m = 2n, where m and n are both integers.
 A m-to-1 Multiplexer has
m Inputs: I0, I1, I2, ................ I(m-1)
one Output: Y
n Control inputs: S0, S1, S2, ...... S(n-1)
One (or more) Enable input(s)
such that Y may be equal to one of the inputs, depending upon the
control inputs.
EXAMPLE OF A COMBINATORIAL CIRCUIT:
A MULTIPLEXER (MUX)
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14. Implementing Digital Functions:
by using a Multiplexer:
In this example to design a 3 variable logical function, we try to
use a 4-to-1 MUX rather than a 8-to-1 MUX.
F(x, y, z)=∑ (m(1, 2, 4, 7)
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15. Implementing Digital Functions:
by using a Multiplexer: continue……
In a canonic form:
F = x’.y’.z+ x’.y.z’+x.y’.z’ +x.y.z …… (1)
One Possible Solution:
Assume that x = S1 , y =S0 .
If F is to be obtained from the output of a 4-to-1 MUX,
F =S’1. S’0. I0 + S’1. S0. I1 +S1. S’0. I2 + S1. S0. I3 ….(2)
From (1) and (2),
I0 = I3 =Z I1 = I2 =Z’
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16. Implementing Digital Functions:
by using a Multiplexer: continue……
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17. Another Possible Solution:
Assume that z = S1 , x =S0 .
If F is to be obtained from the output of a 4-to-1 MUX,
F = S’0 .I0 . S1 + S’0 .I1 . S’1 + S0 .I2 . S’1 + S0 .I3 . S1 ………… (3)
From (1) and (2),
I0 = y’ = I2
I1 = y = I3
Implementing Digital Functions:
by using a Multiplexer: continue……
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18. Implementing Digital Functions:
by using a Multiplexer: continue……
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19. THANK YOU
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