Realization of Full Adder using 3 to 8 Decoder

REALISATION OF FULL ADDER USING 3 TO 8 DECODER

AIM:

To set up a full adder using 3 to 8 decoder IC.

MATERIALS AND TOOLS REQUIRED:

 Mux IC 74151, Digital IC trainer Kit and Power supply.

THEORY:

A decoder is a MSI combination logic IC which has N inputs and 2^N outputs, corresponding to the minterms of the input, such that exactly one output is active for each combination of the input variables. Any function of N variables can then be obtained by OR ing together the appropriate combination of minterms from the output of the decoder. Since the full adder has three inputs, we will use the 74LS138 single 3-to-8 decoder for this experiment. For implementing a full adder, the three inputs are A , B and Cin.

Circuit Diagram:

PROCEDURE:

            Test the decoder IC using Digital IC tester. Set up the circuit as shown in figure. Apply the three inputs and verify the outputs at Sum and Cout.

RESULT:

A full adder circuit using 3 to 8 decoder IC 74138 is set up.