Presentation On Logic Gate

I discussed here different kinds of logic gate , their equivalent circuit, truth table,set representation,wave form etc. I also have discussed universal gate and their universality. I hope it will be helpful for others.

1. WELCOME To my presentation Assalamulaikum Md. Nazrul Islam B.Sc in CSE University of Chittagong

2. Contents of Presentation What is logic gate? Why it is used? Basic logic gates Universal logic gates Universality of NAND & NOR gate Exclusive logic gates Compound or Complex logic gate

3. Logic Gate: A logic gate is a building block of a Digital Circuit which takes two or more inputs and gives only one output based on Boolean algebra. Use of logic gates Logic circuits  include such devices as multiplexers, registers, arithmetic logic units(ALUs), and computer memory,  microprocessors, Integrated circuits, discrete electronic components, simple switches, relays , hydraulic etc.

4. Kinds of logic gates 1.Basic logic gate 2.Universal logic gate 3.Exclusive gate 4.Compound or complex gate

5. Basic logic gate AND GATE AND gate is an electronic circuit which is used for Boolean algebra or logical Multiplication . If two input A,B and output is Y . Then we get Y = A AND B =A.B =AB

6. AND gate It gives a  high  output (1) only if  all  its inputs are high. If A&B two sets then we can define “AND” operation by Venn diagram. It would be like this.

7. AND gate The wave form of AND gate for two input A&B.. A B Y Three input AND gate

8. 2.OR gate OR gate is an electronic circuit which is used for Boolean algebra or logical summation . If two input A,B and output is Y . Then we get Y = A OR B =A+B

9. 2.OR gate It gives a high output (1) if  one or more  of its inputs are high. If we represent the “OR GATE” By Venn Diagram then we can see thus

10. 2.OR gate The wave form of “OR” gate for two input A&B.. Three input OR gate

11. 3.NOT gate “NOT” gate is an electronic circuit which is used for Complement work. Its also called “Inverter”. It contains 1 input and 1 output. If input is 1 then output will be 0,and if input is 0 then output will be 1. If 1 input is A and output is Z . Then we get Z = NOT A =VAR OF A

12. 2.Universal Logic gate (I) NAND gate: NAND gate consist of AND + NOT gate. The outputs of all NAND gates are high if  any  of the inputs are low. If 2 input is A ,B and output is Z . Then we get Z = NOT (A and B) =VAR OF ( A.B) Venn Diagram

13. 2.Universal Logic gate(NAND) Universality of NAND NAND gate NOT gate NAND gate AND gate OR gate

14. 2.Universal Logic gate (II) NOR gate: NOR gate consist of OR + NOT gate. The outputs of all NOR gates are low if  any  of the inputs are high. If 2 input is A ,B and output is Z . Then we get Z = NOT (A+B) =VAR OF ( A+B)

15. 2.Universal Logic gate(NOR) Universality of NOR

16. 3.EXCLUSIVE gate (I) XOR gate XOR gate  is a digital logic gate  that gives a true (1 or HIGH) output when the number of true inputs is odd. Truth Table

17. 3.EXCLUSIVE gate (II) XNOR gate The  XNOR gate is a digital logic gate whose function is the logical complement of the exclusive OR ( XOR ) gate.  Truth Table

18. 4.Compound or Complex gate Compound logic gates  (sometimes  Complex logic gate ) are simple devices that function like a few basic logic gates combined. It would be many types.Such as: 1.AND-OR-Invert (AOI) 2.OR-AND-Invert (OAI) 2-1 AOI

19. Thank You