Logic Gates
The logic gates is basic building blocks of electronics logic circuits for large circuit its is more complex and no of logic gates is increase. These logic gates perform a basic Boolean functions , such as AND, OR, NAND, NOR, Inversion, Exclusive-OR, Exclusive-NOR. Boolean function, and truth. It is seen from the Fig that each gate has one or two binary inputs, A and B, and one binary output, C.
The different types of logic gates are:
NOT Gate
The inverter is a logic gate which has only one input & one output. In inverter is Always opposite of input.
which means if set input LOW is output HIGH.if set input HIGH is output is LOW. the output is given below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| X | X = X | DIAGRAM | |
| 0 | 1 |
| |
| 1 | 0 | ||
AND Gate
AND gate is a logic gate Which can have two or more inputs.But there is only one output.
The output of AND gate is high only if all inputs are HIGH .
Even if one input is LOW the output is LOW. the output is given below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | X = A . B | DIAGRAM |
| 0 | 0 | 0 |
|
| 0 | 1 | 0 | |
| 1 | 0 | 0 | |
| 1 | 1 | 1 | |
OR Gate
OR gate is a logic gate Which can have two or more inputs.But there is only one output.
The output of OR gate is HIGH only if a one of the inputs are HIGH Even if one input is LOW, the output will HIGH. Only when both of input is zero the output will also LOW. the output is given below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | X = A + B | DIAGRAM |
| 0 | 0 | 0 |
|
| 0 | 1 | 1 | |
| 1 | 0 | 1 | |
| 1 | 1 | 1 | |
NAND Gate
NAND gate is a logic gate Which can have two or more inputs.But there is only one output.
NAND is Compliment of AND .The output of NAND gate is HIGH only if one inputs are HIGH or both input being LOW.if both input is HIGH the output is LOW, the output is given below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | X = A . B | DIAGRAM |
| 0 | 0 | 1 |
|
| 0 | 1 | 1 | |
| 1 | 0 | 1 | |
| 1 | 1 | 0 | |
XOR Gate
XOR gate is a logic gate Which can have two or more inputs.But there is only one output.
The output of XOR gate is HIGH only if one of the inputs are HIGH.
if both input is same the output is LOW, the output will below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | X = A ⊕ B | DIAGRAM |
| 0 | 0 | 0 |
|
| 0 | 1 | 1 | |
| 1 | 0 | 1 | |
| 1 | 1 | 0 | |
NOR Gate
NOR gate is a logic gate Which can have two or more inputs.But there is only one output.
NOR Gate is Compliment of OR. The output of NOR gate is HIGH only if both inputs are LOW.if Any input is HIGH the output is LOW, the output is given below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | X = A + B | DIAGRAM |
| 0 | 0 | 1 |
|
| 0 | 1 | 0 | |
| 1 | 0 | 0 | |
| 1 | 1 | 0 | |
XNOR Gate
XNOR gate is a logic gate. Which can have two or more inputs.But there is only one output.
XNOR Is Compliment of XOR . The output of NAND gate is HIGH only if Both inputs are same.
if both input is different the output is LOW, the output will below.
| TRUTH TABLE | |||
|---|---|---|---|
| INPUT | OUTPUT | ||
| A | B | X = A ⊕ B | DIAGRAM |
| 0 | 0 | 1 |
|
| 0 | 1 | 0 | |
| 1 | 0 | 0 | |
| 1 | 1 | 1 | |
See Also in To Study and Verify the Truth Table of Logic Gates.
Designing and Simulating Digital Logic Circuits
