OR gate

INPUT		OUTPUT
A	B	A OR B
0	0	0
0	1	1
1	0	1
1	1	1

The OR gate is a logic gate that outputs 1 (true) when at least one of its inputs is 1 (true). That means that if both of its inputs are 0, the output will be 0.

The best way to remember an OR operation is "one or the other, or both."

Symbols

There are three symbols for the OR gate:

MIL/ANSI Symbol	IEC Symbol	DIN Symbol

OR Gate Media

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  This schematic diagram shows the arrangement of four OR gates within a standard 4071 CMOS integrated circuit.

• 

  A labelled MIL/ANSI symbol for an OR gate. A and B are the inputs, Q is the output

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  OR Gate constructed from a NAND Gates.

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  OR Gate constructed from NOR Gates

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  Wired OR gate using open-collector NOR gates