Electrical Engineering ⇒ Topic : Half Adder Circuits

HALF ADDER CIRCUITS

The circuit which adds two bits, ignoring the carry from the previous bit addition, is called half adder circuit. It has two inputs and two outputs. The two inputs are the two bits which are to be added. The two outputs are the resultant sum and the carry generated by the addition.

Table (1) shows the binary summation.

                                         Table (1) Binary summation

The boolean expression representing the above truth table would be:

This is in SOP form and one can easily draw circuit for it. We are using the AND and OR gates in this circuit as shown in Figure (2). We can also design this circuit using NAND or NOR gates.

                                   Figure (2) Half adder