Half Subtractor

·         Half Subtractor is a combinational logic circuit.

·         It is used to perform substraction between two single bit numbers.

·         It contains 2 inputs and 2 outputs (difference and borrow).

Half Subtractor Designing-

Half subtractor is designed in the following steps-

Step-01:

Identify the input and output variables-

·         Input variables = A, B (either 0 or 1)

·         Output variables = D, b where D = Difference and b = borrow

Step-02:

Draw the truth table-

Step-03:

Draw K-maps using the above truth table and determine the simplified Boolean expressions-

Step-04:

Draw the logic diagram.

The implementation of half subtractor using 1 XOR gate, 1 NOT gate and 1 AND gate is as shown below-