The output of an AND gate is in the high logic level only IF either input (A or B) is in the high logic level. Figure 1 shows the symbol of an AND gate and the equivalent circuits.
Equation 1
2-Input AND Gate
X = A.B
Where:
X is the output logic level
A and B are the input logic level
Truth Table
| A | B | X |
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
Equation 2
3-Input AND Gate
X = A.B.C
Where:
X is the output logic level
A, B, C are the input logic level
Truth Table
