Logic Gates

A and B are the inputs, x is the output.

Gate Descriptions

Name Graphic Symbol Algebraic Symbol Truth Table
AND
AND GATE
x = AB
 

 A B | x
 ----+--
 0 0 | 0
 0 1 | 0
 1 0 | 0
 1 1 | 1
OR
OR GATE
x = A + B
 

 A B | x
 ----+--
 0 0 | 0
 0 1 | 1
 1 0 | 1
 1 1 | 1
Inverter
INVERTER
x = A'
 

 A | x
 --+--
 0 | 1
 1 | 0
Buffer
BUFFER
x = A
 

 A | x
 --+--
 0 | 0
 1 | 1
NAND
NAND GATE
x = (AB)'
 

 A B | x
 ----+--
 0 0 | 1
 0 1 | 1
 1 0 | 1
 1 1 | 0
NOR
NOR GATE
x = (A + B)'
 

 A B | x
 ----+--
 0 0 | 1
 0 1 | 0
 1 0 | 0
 1 1 | 0
XOR
Exclusive-OR
XOR GATE
x = A'B + AB'
or
x = A (+) B
 

 A B | x
 ----+--
 0 0 | 0
 0 1 | 1
 1 0 | 1
 1 1 | 0
XNOR
XNOR GATE
x = A'B' + AB
or
x = (A (+) B)'
 

 A B | x
 ----+--
 0 0 | 1
 0 1 | 0
 1 0 | 0
 1 1 | 1

Alternate Gates

Original SymbolAlternate Symbol