Multiplexer, we can simply say that a circuit which can deliver single output from multiple inputs. It can often refer as data selector or mux. The inputs to this circuit may be Analog or Digital. It is very useful in sending large amount of data over a network with decrease in bandwidth and time. A single pole multi-positioned switch is a plain example of a multiplexer which is not having an electronic circuit or components. But for high speed switching, automatically selecting electronic multiplexers are implemented. Multiplexers that are built from transistors and relays are employed for analog applications. In digital applications, standard logic gates are used to build it. They are also termed as digital multiplexer.2 to 1 multiplexer This circuit selects one of the inputs with the help of control signals and delivers that particular input into a single line as output.

Therefore, it is also termed as data selector. The figure below shows the pin diagram of multiplexer. pin diagram of multiplexer

4 to 1 Multiplexer

For understanding the multiplexer further, we are selecting a 4-to-1 Multiplexer. There are many others like 2-to-1, 8-to-1, 16-to-1 multiplexers etc. In this multiplexer, the details are the following:
  • Inputs
    As the name indicates, there are 4 input bits. They are D0, D1, D2 and D3.
  • Output
    The number of output is one and is referred as Y.
  • Control Bits
    Two control bits are used here, A and B. This will decide which input bit should have to be selected. The output clearly depends on this control bits.
4 to 1 multiplexer If the condition AB = 00, the top most AND gate is enabled (shown in figure above). At this time, all the other three AND gates are in disabled condition. So, input bit D0 is selected and transmitted as output. Thus, Y = D0.
If the condition AB = 11, every other AND gates are disabled excluding the bottom most AND gate. So, input bit D3 is selected and transmitted as output. Thus, Y = D3.
The examples of multiplexers are IC 74153, IC 45352 (4-to-1 multiplexers), IC 74150 (16-to-1 multiplexer)

Applications of Multiplexer

Multiplexers are implemented in several fields where there is a necessity of transmitting large amount of data with use of single line.
Computer Memory
In computer, the huge quantity of memory is implemented by means of multiplexers. It also has advantage of reduction in number of copper lines which are used for the connection of memory to other parts in the computer.
Communication System
Multiplexer is implemented in this system to increase efficiency. Using a single transmission line, various types of data (video, audio etc) are transmitted at the same instant.
Telephone Network
Here, the multiple audio signals are brought into a single line and transmitted with the implementation of multiplexer. By this method, the numerous audio signals are made isolated and ultimately the recipient will receive the required audio signals.
Computer System of a Satellite Transmission
Multiplexers are implemented for the data signals to be transmitted from space craft or computer system of satellite to the earth by means of GPS.

Closely Related Articles Binary Adder Half and Full AdderBinary SubstractorSeven Segment DisplayBinary to Gray Code Converter and Grey to Binary Code ConverterBinary to BCD Code ConverterAnalog to Digital ConverterDigital Encoder or Binary EncoderBinary DecoderBasic Digital CounterDigital ComparatorBCD to Seven Segment DecoderParallel AdderParallel Adder or SubtractorDemultiplexer555 Timer and 555 Timer WorkingLook Ahead Carry AdderMore Related Articles Digital ElectronicsBoolean Algebra Theorems and Laws of Boolean AlgebraDe Morgan Theorem and Demorgans LawsTruth Tables for Digital LogicBinary Arithmetic Binary AdditionBinary SubtractionSimplifying Boolean Expression using K MapBinary DivisionExcess 3 Code Addition and SubtractionK Map or Karnaugh MapSwitching Algebra or Boolean AlgebraBinary MultiplicationParallel SubtractorOR Operation | Logical OR OperationAND Operation | Logical AND OperationLogical OR GateLogical AND GateNOT GateUniversal Gate | NAND and NOR Gate as Universal GateNAND GateDiode and Transistor NAND Gate or DTL NAND Gate and NAND Gate ICsX OR Gate and X NOR GateTransistor Transistor Logic or TTLNOR GateFan Out of Logic GatesINHIBIT GateNMOS Logic and PMOS LogicSchmitt GatesLogic Families Significance and Types of Logic FamiliesBinary Number System | Binary to Decimal and Decimal to Binary ConversionBinary to Decimal and Decimal to Binary ConversionBCD or Binary Coded Decimal | BCD Conversion Addition SubtractionBinary to Octal and Octal Binary ConversionOctal to Decimal and Decimal to Octal ConversionBinary to Hexadecimal and Hex Binary ConversionHexadecimal to Decimal and Decimal to Hexadecimal ConversionGray Code | Binary to Gray Code and that to Binary ConversionOctal Number SystemDigital Logic Gates2′s Complement1′s ComplementASCII CodeHamming Code2s Complement ArithmeticError Detection and Correction Codes9s complement and 10s complement | SubtractionSome Common Applications of Logic GatesKeyboard EncoderAlphanumeric codes | ASCII code | EBCDIC code | UNICODELatches and Flip FlopsS R Flip Flop S R LatchActive Low S R Latch and Flip FlopGated S R Latches or Clocked S R Flip FlopsD Flip Flop or D LatchJ K Flip FlopMaster Slave Flip FlopRead Only Memory | ROMProgrammable Logic DevicesProgrammable Array LogicApplication of Flip FlopsShift RegistersBuffer Register and Controlled Buffer RegisterData Transfer in Shift RegistersSerial In Serial Out (SISO) Shift RegisterSerial in Parallel Out (SIPO) Shift RegisterParallel in Serial Out (PISO) Shift RegisterParallel in Parallel Out (PIPO) Shift RegisterUniversal Shift RegistersBidirectional Shift RegisterDynamic Shift RegisterApplications of Shift RegistersUninterruptible Power Supply | UPSConversion of Flip FlopsJohnson CounterSequence GeneratorRing CounterNew Articles Series and Parallel Inductors Electric PowerMeasurement of Losses in Shunt ReactorThree Phase Shunt ReactorMeasurement of Insulation ResistanceAmpere's Circuital Law
electrical engineering app