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AND gate

 
Dictionary: AND gate

n.
A logic gate that simulates the function of the logical operator AND. It emits a signal only if all input wires receive coincident signals.


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WordNet: AND gate
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Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: a circuit in a computer that fires only when all of its inputs fire
  Synonym: AND circuit


Wikipedia: AND gate
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INPUT OUTPUT
A B A AND B
0 0 0
0 1 0
1 0 0
1 1 1

The AND gate is a digital logic gate that implements logical conjunction - it behaves according to the truth table to the right. A HIGH output (1) results only if both the inputs to the AND gate are HIGH (1). If neither or only one input to the AND gate is HIGH, a LOW output results. In another sense, the function of AND effectively finds the minimum between two binary digits, just as the OR function finds the maximum.

Contents

Symbols

There are three symbols for AND gates: the Texan (ANSI or 'military') symbol and the IEC ('European' or 'rectangular') symbol, as well as the deprecated DIN symbol. For more information see Logic Gate Symbols.

AND ANSI Labelled.svg AND IEC.svg AND DIN.svg
MIL/ANSI Symbol IEC Symbol DIN Symbol

The AND gate with inputs A and B and output C implements the logical expression C = A \cdot B.

Implementations

NMOS AND gate

An AND gate is usually designed using NMOS (pictured) or PMOS MOSFETs. The digital inputs a and b cause the output F to have the same result as the AND function.

Alternatives

AND Gate Constructed Using Only NAND Gates

If no specific AND gates are available, one can be made from NAND or NOR gates, because NAND and NOR gates are considered the "universal gates,"[1] meaning that they can be used to make all the others. The configuration shown on the right shows how to use NAND gates to create the effect of an AND gate.

See also

References

  1. ^ Mano, M. Morris and Charles R. Kime. Logic and Computer Design Fundamentals, Third Edition. Prentice Hall, 2004. p. 73.

 
 

 

Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
WordNet. WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved.  Read more
Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "AND gate" Read more