New Document
Electronics
Electronics Catlog
DIC Catlog

Number System
Conversions Between Number System
Arithematic Operations
1's & 2's Complement
Gray Codes
Arithmetic Circuits
Logical Gates and Truth Table Funtions
Boolean Expressions
Boolean Algebra
Karnaugh Map
Multiplexer
DeMultiplexer
Encoder & Decoder
TTL Circuits
Multivibrators
555 Timer
Flip Flops
RS Flip - Flop
JK Flip - Flop
D Flip - Flop
Shift Register
Schmitt Trigger
Asynchronous Counters
Synchronous Counters
Digital - Analog Conversion
Data Flow
ROM
Memory Drives
Electronics Equation
Resistor Color Codes

Circuit Implementation Using Multiplexers


What is a multiplexer?


    It quite often happens, in the design of large-scale digital systems, that a single line is required to carry two or more different digital signals. Of course, only one signal at a time can be placed on the one line. What is required is a device that will allow us to select, at different instants, the signal we wish to place on this common line. Such a circuit is referred to as a Multiplexer.


    A multiplexer performs the function of selecting the input on any one of 'n' input lines and feeding this input to one output line.

    Multiplexers are used as one method of reducing the number of integrated circuit packages required by a particular circuit design. This in turn reduces the cost of the system.

    Assume that we have four lines, C0, C1, C2 and C3, which are to be multiplexed on a single line, Output (f). The four input lines are also known as the Data Inputs. Since there are four inputs, we will need two additional inputs to the multiplexer, known as the Select Inputs, to select which of the C inputs is to appear at the output. Call these select lines A and B.

    The gate implementation of a 4-line to 1-line multiplexer is shown below:

Multiplexer

The circuit symbol for the above multiplexer is:


Multiplexer Circuit Symbol

    Design multiplexer implementations for the following functions using the numerical method.

The simulation should be used to check the workings.

    Multiplexer Ex01

    Multiplexer Ex02

    Multiplexer Ex03

    Multiplexer Ex04