The half subtractor is a digital circuit that takes two binary inputs, A and B, and produces the difference and borrow outputs. It uses an XOR gate to produce the difference output of A'B + AB' and an AND gate with an inverter to produce the borrow output of AB'. The document provides the truth table and circuit diagram for a half subtractor and describes building a half subtractor circuit on a breadboard to verify its functionality based on the truth table.

1. LAB 3
Half Subtractor:
The half subtractor is constructed using XOR & AND Gate. The half subtractor
has two input and two outputs. The outputs are difference and borrow. The
difference can be applied using XOR Gate, borrow output can be implemented
using an AND Gate and an inverter.
Subtraction = A’B + AB’ Borrow = A’B
1. Truth Table:
A B Subtraction Borrow
0 0 0 0
0 1 1 1
1 0 1 0
1 1 0 0
2. Circuit Diagram:
Objectives:
Design and construct half subtractor circuit & verify its truth tables using logic
gates.
Components Required:
 Bread Board, Power Supply, Jumper Wires
 Two LEDs & Two Switches, XOR, AND & Inverter
Procedure:
 Connections are given as per circuit diagram.
 Logical inputs are given as per circuit diagram.
 Observe the output and verify the truth table.

2. Circuit:
Truth Table:
A B SUB = A’B + AB’ Borrow = AB’
0 0 0 0
0 1 1 1
1 0 1 0
1 1 0 0