AND gate

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.

[edit] Symbols

There are two symbols for AND gates: the 'military' symbol and the 'rectangular' symbol. These are also known as the 'American' and 'British' symbols. For more information see logic gate symbols

Equation:- output(C) = i/p(A)+ i/p(B).

'American Standard' AND symbol

'English Standard' AND symbol

This schematic diagram shows the arrangement of AND gates within a standard 4081 CMOS integrated circuit.

[edit] Hardware description and pinout

AND Gates are basic logic gates, and are implemented in both TTL and CMOS technology ICs. The '4000 series' CMOS IC AND gate device is designated the 4081, which includes four independent, two-input, AND gates.

This d

As well as the standard 2-Input AND Gate, 3-, 4- and 8-Input AND Gates are also available:

• 4073: Triple 3-Input AND Gate
• 4082: Dual 4-Input AND Gate
• An 8-Input NAND Gate exists (4068), and this is easily made into an 8-Input AND gate by inversion of the output.

[edit] 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.

[edit] 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.

[edit] See also

• OR gate
• NOT gate
• NAND gate
• NOR gate
• XOR gate
• Boolean algebra (logic)
• Logic gates

v • d • e Logical connectives Tautology OR · ← · → · NAND Proposition • XOR · XNOR • Negation AND · ↛ · ↚ · NOR Contradiction

[edit] References