Logic gates are electronic digital circuits that perform logic functions. The common logic gates are AND, OR, NOT, NAND, NOR, XOR, and XNOR. Each gate has a corresponding logic symbol and truth table. Logic gates can be combined to build more complex digital circuits like adders, subtractors, and parity checkers. Common logic gate integrated circuits include the 7400, 7402, 7404, 7408, and 7432 series, with each having a specific pin configuration. Logic gates are fundamental building blocks for digital electronics.

1. By
~Nilanjan Ghosh
LOGIC GATES

2. Logic Gates
 Logic gates are electronic
digital circuit perform logic
functions. Commonly expected
logic functions are already
having the corresponding logic
circuits in Integrated Circuit (I.C.)
form.
 Each gate has its own logic
symbol which allows complex
functions to be represented by
a logic diagram
 The function of each gate can
be represented by a Truth Table
or using Boolean Notation

3. Types Of Gates
Two types of Logic gate –
Basic Gate
AND , OR , NOT
Derived Gate
NAND , NOR , XOR

4. Basic Gates
The AND Gate

5. The OR Gate

6. The NOT Gate

7. The BUFFER Gate

8. Derived Gate
The NAND Gate

9. The NOR Gate

10. The EXCLUSIVE OR Gate

11. The EXCLUSIVE NOR Gate

12. De-Morgan’s Theorem and Logic
Conversion

13. Universal GATE (NAND,NOR)

14. Application Of Logic Gate
OR Gate- Wherever the occurrence of any
one or more than one event is needed to be detected
or some actions are to be taken after their occurrence,
in all those cases OR gates can be used.
AND Gate- There are mainly two
applications of AND gate as Enable gate and
Inhibit gate. Enable gate means allowance of
data through a channel and Inhibit gate is just the
reverse of that process i.e. disallowance of data
through a channel

15. NOT Gate- NOT gates are also known as
inverter because they invert the output given to them
and show the reverse result. Now the CMOS inverters
are commonly used to build square wave oscillators
which are used for generating clock signals
X-OR/NOR GATE- These type of logic
gates are used in generation of parity generation and
checking units.

16. Further Application of Logic Gates
 1. HALF ADDER CIRCUIT USING NAND , NOR GATE

17. 2. FULL ADDER CIRCUIT USING NAND & NOR

18. 3. HALF & FULL SUBTRACTOR CIRCUIT USING NAND & NOR

19. 4. EVEN AND ODD PARITY CHECKER

20. Logic Gates IC Datasheet Pin
Configuration
 7400 Quad 2 input NAND gates
 7402 Quad 2 input NOR gates
 7404 Hex NOT gates (Inverters)
 7408 Quad 2 input AND gates
 7432 Quad 2 input OR gates
 7486 Quad 2 input XOR gates
 747266 Quad 2 input XNOR gates
 74133 Single 13 input NAND gate