True

1. HALF ADDER
AND
FULL ADDER

2. •Adder : In electronics an adder is digital circuit
perform addition of numbers. In modern computer adder
reside in arithmetic logic unit (ALU).
•Adder are not important not only in the computer but
also in many types of digtal system in which the numeric
data are processed .

3. 2: Full Adder
There are 2 types of Adder.
1: Half Adder

4. Representation of half adder :
•The Half Adder accept two binary digits on its input and produce two binary digits output ,a
sum bit and a carry bit (i.e. It contains 2 inputs and 2 outputs .)
Truth-Table :

5. Boolean expression for the logic diagram :
1: For Sum : A`B + AB`
2: For Carry : AB

6. Using NAND Gate : Using NOR Gate :

7. Representation of Full Adder :
The half adder is used to add only two numbers. To overcome this problem, the
full adder was developed. The full adder is used to add three 1-bit binary
numbers A, B, and carry C. The full adder has three input states and two output
states i.e. sum and carry .
Truth Table :

8. SOP form of sum and carry :
1: Sum : A`B`C + A`BC` + AB`C` + ABC
2: Carry : A`BC + AB`C + ABC` + ABC

9. •Using Carry as AB+BC+CA :
In circuit the propagation delay of all logic
gate are assumed to be same then to
generate sum 2TPD delay and to generate
carry 2 TPD delay is used .

10. 1 : Half Adder : To implement full adder using half
adder we need 2 half adder and 1 OR gate.

11. 2: Using NAND Gate : NAND gate is one of the
universal gates and can be used to implement any
logic design. The circuit of full adder using only
NAND gates is shown below.

12. •Prathamesh Upreti
•Roll No. :
211190101023