Electronics/Basic gates

Overview

There are five different types of gate at the most simple stage:

1. AND
2. OR
3. NOT
4. NAND
5. NOR
6. XOR

(NB: They should always be referenced in capitals)

The explanations below are for fully digital operation. See below for practical limitations and information (i.e., trip points.)

All logic functions can be implemented using only:

• AND, OR, NOT
• NAND
• NOR

Explanation of the gates' operation

1. AND Gate

• The AND gate's output is 1 if both of its two inputs are 1; otherwise, the output will be 0

AND gate

AND

A	B	X
0	0	0
0	1	0
1	0	0
1	1	1

2. OR Gate

• The OR gate's output is 1 if either of its two inputs are 1; otherwise, the output is 0

OR gate

OR

A	B	X
0	0	0
0	1	1
1	0	1
1	1	1

3. NOT Gate

• The output from the NOT gate is always equal to the opposite of the input

NOT gate

NOT

A	X
0	1
1	0

4. NAND Gate

• As if a NOT gate had been stuck on the end of an AND gate; i.e., if both inputs are 1, the output will be 0, else it will be 1

NAND gate

NAND

A	B	X
0	0	1
0	1	1
1	0	1
1	1	0

5. NOR Gate

• As if a NOT gate had been stuck on the end of an OR gate; i.e., if either input is 1, the output will be 0, else it will be 1

NOR gate

NOR

A	B	X
0	0	1
0	1	0
1	0	0
1	1	0

6. XOR gate

• This gate is identical to the OR gate except for when the inputs are the same - in this case it is 0 as well

XOR gate

XOR

A	B	X
0	0	0
0	1	1
1	0	1
1	1	0