An OR gate is a type of digital logic gate that implements logical disjunction. It outputs a logic high level (often denoted as a logic ‘1’) when one or more of its inputs are logic high. It typically has two binary inputs and one binary output. An OR gate generates its output by using the logic function known as the inclusive OR, which is usually expressed as y = A + B. The OR gate is the most basic logic gate, and is often used as part of the fundamental circuitry of computers, electronic devices, and other digital systems.
The OR gate is one of the three basic logic gates, along with the NOT gate and the AND gate. In digital electronics, an OR gate is typically implemented using transistors, however, other logic gate types such as NAND and NOR gates may also be used. OR gates are often used in conjunction with the other two gate types to create complex logic functions.
The OR gate is often used in combination with other logic gates, such as an AND gate, to create more complex digital logic circuits such as a half adder or full adder. An OR gate can be used to construct a simple circuit to detect any one of two conditions, such as if one of two switches is turned on or if one of two inputs are high.
The OR gate is sometimes referred to as an inclusive OR logic gate. In Boolean algebra, the OR gate is often written as a + sign instead of a logic symbol. OR gates also have applications in sequential logic circuits, such as flip-flops and counter circuits.
The OR gate is an important component in digital logic circuits and is used widely in many applications, from computer systems to cellular phones. Its versatile and functional design makes it a popular choice when building high performance digital circuits.
