## What is Adder, Definitions, Type, Advantage & Disadvantage

###### Authored By: Ankita Prajapati

Adder is a type of digital arithmetic unit used in a variety of digital circuits. It is used to add two numbers and produces an output sum. An adder is a fundamental building block of many digital circuits, and is used in a variety of applications such as digital signal processing, computer arithmetic, and image processing.

## Types

There are two types of adder:-

- Half Adder
- Full Adder

Join the vibrant **Electrical & Electronics Engineers** community

## Half Adder

The half adder is a simpler version of the full adder, as it only has two inputs (A and B) and two outputs (Sum and Carry–out). The two inputs are the two binary numbers to be added, while the two outputs are the sum of the two input numbers and the carry–out.

The half adder works by using two 2–input XOR gates to calculate the sum and a 2–input AND gate to calculate the carry–out.

The two XOR gates add the two input numbers, while the AND gate takes the logical AND of the two input numbers to calculate the carry–out. The half adder is a simpler version of the full adder, as it only has two inputs (A and B) and two outputs (Sum and Carry–out). The two inputs are the two binary numbers to be added, while the two outputs are the sum of the two input numbers and the carry–out.

## Join Engineering Communities and Events related to your Career Path.

The half adder works by using two 2–input XOR gates to calculate the sum and a 2–input AND gate to calculate the carry–out. The two XOR gates add the two input numbers, while the AND gate takes the logical AND of the two input numbers to calculate the carry–out.

## Full Adder

The full adder is composed of three inputs (A, B and Carry–in) and two outputs (Sum and Carry–out). The three inputs are the two binary numbers to be added and the carry–in, which is a single bit that indicates whether a carry–over from the previous addition is to be considered.

The two outputs are the sum of the two input numbers and the carry–out, which is a single bit that indicates whether a carry–over is to be made to the next addition.

The full adder works by using two 2–input XOR gates to add the two input numbers (A and B) and a 2–input AND gate to calculate the carry–out.

The first XOR gate adds the two input numbers, while the second XOR gate adds the result of the first XOR with the carry–in. The AND gate then calculates the carry–out by taking the logical AND of the two input numbers and the carry–in.

Join the vibrant **Electrical & Electronics Engineers** community

## Advantages

- Simplicity: Adder circuits are relatively simple to design and implement, making them cost-effective and efficient.
- Speed: Adder circuits are fast, providing quick response times when computing large numbers.
- Low power: Adder circuits are designed to consume a minimal amount of power.
- Versatility: Adder circuits can be used to add a variety of numeric values, including binary numbers, BCD numbers, and other numerical values.

## Disadvantages

- Limited accuracy: Adder circuits are limited in their accuracy as they can only add two numbers at a time.
- Limited range: Adder circuits can only add a limited range of numbers.
- Complexity: Adder circuits can become complex when adding large numbers, requiring additional components and logic gates.
- Non-programmable: Adder circuits are non-programmable, meaning they cannot be modified or reprogrammed.

## Join Engineering Communities and Events related to your Career Path.

## Conclusion

Overall, Adder circuits are a useful tool in digital circuits, providing a simple and fast way to add two numbers and produce an output sum.

However, their limited range of accuracy and complexity can be an issue when attempting to add large numbers. Additionally, the fact that they are non-programmable can be limiting when designing more complex systems.