Logic Gates and their Types

What are Logic Gates?

A logic gate is an idealized or physical electronic device implementing a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. 

Logic gates are primarily implemented using diodes or transistors acting as electronic switches, but can also be constructed using vacuum tubes, electromagnetic relays (relay logic), fluidic logic, pneumatic logic, optics, molecules or even mechanical elements. With amplification, logic gates can be cascaded in the same way that boolean functions can be composed, allowing the construction of a physical model of all of boolean logic, and therefore, all of the algorithms and mathematics that can be described with boolean logic.

Types of Logic Gates

OR Gate

If any of the input is high, then the output is high.

NOR Gate

If both the inputs are low, then the output is high, otherwise low.

NAND Gate

If both the inputs are high, then the output is low, otherwise high.

EX-OR Gate

If both the inputs are high or low, then the output is low, otherwise high.

EX-NOR Gate

If both the inputs are high or low, then the output is high, otherwise low.

NOT Gate

The output is inversely proportional to the input.

Advantages of Logic Gates

• Logic gates are quick yet use low energy.
• Logic gates do not get overworked.
• Logic gates can lesser the prescribed number of I/O ports needed by a microcontroller.
• Logic gates can bring about straightforward data encryption and decryption.

Disadvantages of Logic Gates

The disadvantages of Logic Gates are:

• Operating Voltage is limited.
• Time delay occurs between input and output.

Applications of Logic Gates

The applications of Logic Gates are:

• NAND Gates are used in Burglar alarms and buzzers.
• They are basically used in circuits involving computation and processing.
• They are also used in push button switches. E.g. Doorbell.
• They are used in the functioning of streetlights.
• AND Gates are used to enable/inhibit the data transfer function.
• They are also used in TTL (Transistor Transistor Logic) and CMOS circuitry.