Verification of the truth table of the De-Multiplexer 74154.

Aim

Verification of the truth table of the De-Multiplexer 74154.

Apparatus Required:

Logic trainer kit, IC- 74154, wires.

Theory:

A Demultiplexer performs the reverse operation of a Multiplexer. It accepts a single input and distributes it over several outputs. The SELECT input code determines to which output the data input will be transmitted. The Demultiplexer becomes enabled when the strobe signal is active LOW. This circuit can also be used as binary-to-decimal decoder with binary inputs applied at the select input lines and the output will be obtained on the corresponding line. These devices are available as 2-line-to-4-line decoder, 3-line-to- 8-line decoder, 4-line-to-16-line decoder. The output of these devices is active LOW. Also there is an active low enable/data input terminal available. Figure below shows the block diagram of a Demultiplexer.

Pin configuration:

Function table:

In this diagram the inputs and outputs are indicated by means of broad arrows to indicate that there may be one or more lines. Depending upon the digital code applied at the SELECT inputs, one data is transmitted to the single output channel out of many. The pin out of a 16:1 Demultiplexer IC 74154 is shown above. The output of this circuit is active low. This is a 24-pin DIP.

Truth Table

Procedure:

Conclusion:

Hence verified the Demultiplexer (16:1) operation using IC-74154.

Precautions