The AND Logic gate has two or more inputs and a single output. It performs logical multiplication. The symbol for a 2-input AND gate, Input voltages can be LOW, logic 0, or HIGH, logic 1. A logic gate is an idealized device implementing a Boolean function, that is, it performs a (TTL) Transistor transistor logical operation on one or more logic inputs and produces a single logic output.
The logic gate is a digital circuit with one or more inputs, with only one outputs. The gate can be constructed from diodes, transistors, and resistors, and its operating power supply voltage is 5v Dc.
CASE 1. A,B Inputs are Low then the output LOW
CASE 2. A Input-Low, B input HIGH then output LOW
CASE 3. A Input-High B input Low then output LOW
CASE 4. A,B inputs are HIGH then the output also HIGH
LOGIC EXPRESSION:- Input variables are A,B and the output variable is Y, then the logic expression for and AND Gate is Y = AB, For more than two input variables the AND expression is Y = ABCD. IC 7408 is a 14 pin, dual-in-line package, consisting of Quad 2-input AND gate.
Application: It allow the passage of a signal from one point to another at certain times and to inhibit (prevent) the passage at other times.