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AND gate

Digital logic gate type

Wikipedia contributorsAdapted for Fathomly · View authors
2 min read
Source updated September 21, 2025
AND gate truth table
InputOutput
ABA AND B
000
010
100
111

The AND gate is a basic digital logic gate that implements the logical conjunction (∧) from mathematical logic , AND gates behave according to their truth table. A HIGH output (1) results only if all the inputs to the AND gate are HIGH (1). If any of the inputs to the AND gate are not HIGH, a LOW (0) is outputted. The function can be extended to any number of inputs by multiple gates up in a chain.

01Symbols

There are three symbols for AND gates: the American (ANSI or 'military') symbol and the IEC ('European' or 'rectangular') symbol, as well as the deprecated DIN symbol. Additional inputs can be added as needed. For more information see the Logic gate symbols article. It can also be denoted as symbol "^" or "&".

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. This expression also may be denoted as C=A\wedge B or C=A\And B.

As of Unicode 16.0.0, the AND gate is also encoded in the Symbols for Legacy Computing Supplement block as U+1CC16 𜰖 LOGIC GATE AND.

02Implementations

In logic families like TTL, NMOS, PMOS and CMOS, an AND gate is built from a NAND gate followed by an inverter. In the CMOS implementation above, transistors T1-T4 realize the NAND gate and transistors T5 and T6 the inverter. The need for an inverter makes AND gates less efficient than NAND gates.

AND gates can also be made from discrete components and are readily available as integrated circuits in several different logic families.

Analytical representation

f(a,b)=a*b is the analytical representation of AND gate:

  • f(0,0)=0*0=0
  • f(0,1)=0*1=0
  • f(1,0)=1*0=0
  • f(1,1)=1*1=1

Alternatives

If no specific AND gates are available, one can be made from NAND or NOR gates, because NAND and NOR gates are "universal gates" meaning that they can be used to make all the others.

Desired gateNAND constructionNOR construction

AND gates with multiple inputs

AND gates with multiple inputs are designated with the same symbol, with more lines leading in. While direct implementations with more than four inputs are possible in logic families like CMOS, these are inefficient. More efficient implementations use a cascade of NAND and NOR gates, as shown in the picture on the right below. This is more efficient than the cascade of AND gates shown on the left.

Watch videos about AND gateExplainers and documentaries on YouTube (opens in a new tab)

Sources and credits

This article is adapted from the Wikipedia article “AND gate”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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Related topics

OR gate

The OR gate is a digital logic gate that implements logical disjunction. The OR gate outputs "true" if any of its inputs is "true"; otherwise it outputs "false".

Inverter (logic gate)

In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. It outputs a bit whose value is opposite of the input bit's value.

NAND gate

In digital electronics, a NAND gate is a logic gate whose output is false only if all its inputs are true; thus its output is complement to that of an AND gate. A LOW (0) output results only if all the inputs to the gate are HIGH (1); if any input is LOW (0), a HIGH (1) output results.