LOGIC Gates (OR_AND_NOT_NOR_NAND_XOR)

LOGIC Gates

  What is the Logic gate?

In electronics, a logic gate is an idealized or physical device implementing a Boolean function; that is, it performs a logical operation on one or more binary inputs and produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device (see Ideal and real op-amps for comparison).

The Truth Table and representative circuit schematic symbol...

1. The OR Gate

The OR gate is an electronic device that receives two inputs each in the form of 

a binary digit, that is 0 or 1, and produces a binary digit as output, depending upon the

values of the two inputs.

2. The AND Gate

It is possible to construct another electronic device called an AND gate which works

in a similar way except that the output only takes the value 1 when both inputs are 1.The logical connective AND is given the symbol · and is known as a conjunction

so that A·B is said to be the conjunction of A and B.

3. The NOT Gate

The invert-er is a device with one input and one output. If the input is A, then the output is

represented by the symbol A, known as the complement of A. 

                                                                                                           

4. The NOR Gate

This gate is logically equivalent to a NOT gate in series with an OR gate.

5. The NAND Gate

This gate is logically equivalent to a NOT gate in series with an AND gate.

6. The XOR Gate

We have already looked at the OR gate. The full name for this type of

OR gate is the inclusive OR gate. It is so called because it gives an output of 1 when

either or both inputs are 1. The exclusive OR gate only gives an output of 1 when

either but not both inputs are 1.

The Simulation in Proteus application...

And Representation circuit schematic...

This is the truth table that you can see on these for compare the result LED HIGH or LOW that we simulation in the Proteus application below. The HIGH is 1 and LOW is 0 for Input and Output.

a). OR Gate 

You can see the LED High or Low follow to Truth table

                                                                                            

Note:  1= HIGH 

           0= LOW

b). AND Gate

c). NOT Gate

d). NOR Gate

e). NAND Gate

f). XOR Gate

g). XNOR Gate

h).XOR using NOT gate, AND gate and OR gate

//Lecturer: Dr. Thap Tharoeun