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OR gate

technology Maturity 11-13

A tiny part helps computers work.

OR ANSI Labelled.svg
OR ANSI Labelled.svg
It looks for a signal. If one part is on, it turns on. It stays on if both parts are on. This helps machines think. Do you like computers?
CMOS 4071 diagram.svg
CMOS 4071 diagram.svg

41 words

A tiny part helps computers work.

OR ANSI Labelled.svg
OR ANSI Labelled.svg
This part looks for a signal. It can have many inputs. If any input is on, the output is on. The output stays on if all inputs are on. It only turns off if every input is off.
CMOS 4071 diagram.svg
CMOS 4071 diagram.svg
This part is very important. It works with two other basic parts. These three parts can build any computer circuit. They help machines do many jobs.

76 words

An OR gate is a tiny part in digital tools.

OR ANSI Labelled.svg
OR ANSI Labelled.svg
It works with signals called bits. Bits can be 1 or 0. You can also call them true or false. The gate looks at its inputs to make a choice. If any input is 1, the output is 1. The output is 0 only if all inputs are 0. This works for gates with two inputs or more.
OR from NAND.svg
OR from NAND.svg
You can also build an OR gate using other parts. These parts are called NAND or NOR gates. This is helpful if you do not have an OR gate. Some chips hold many gates at once. One chip is the 4071. It has four separate OR gates inside.
CMOS 4071 diagram.svg
CMOS 4071 diagram.svg
This chip uses CMOS, which is a way to make parts. Other chips like the 7432 also work. They can work at different speeds. Some use less power too. The OR gate is one of three basic parts. Together with AND and NOT gates, they can make any circuit.

174 words

An OR gate is a very important part of digital tools.

OR ANSI Labelled.svg
OR ANSI Labelled.svg
It is a type of logic gate used in math. These gates help computers make decisions using bits. Bits are tiny bits of information that are either 1 or 0. You might also call these states true or false. They can also be called high or low. The OR gate is one of three basic parts. Together with AND and NOT gates, they can build any circuit.
OR from NAND.svg
OR from NAND.svg

This gate works by looking at its inputs to find a result. It uses a rule called logical disjunction. If any input is a 1, the output becomes a 1. The output is only a 0 if every input is 0. You can think of this like a plus sign. This is because the gate finds the maximum value between bits. It can have two inputs or even more inputs.

OR from NOR.svg
OR from NOR.svg
Some people call it an inclusive OR gate. This helps tell it apart from an exclusive OR gate. An exclusive OR gate is different when both inputs are 1.

Engineers use different symbols to draw these gates.

CMOS 4071 diagram.svg
CMOS 4071 diagram.svg
One symbol is the American or ANSI symbol. There is also a rectangular symbol from the IEC. The IEC symbol has a small mark that says "≥1". This mark means the output turns on with at least one active input. The old DIN symbol is no longer used today. Computers use these symbols to show how parts connect. These drawings help people build complex machines.

Many different chips contain these gates for use. One standard chip is the 4071 CMOS chip. This specific chip holds four separate OR gates inside. Another common device is the 7432 TTL device. There are many other versions of the 7432 chip too. Some versions like the 74HC32 use less power. The 74AC32 version is much faster at switching. There is even a 74LVC32 version for low voltage. Other chips like the 4075 have three inputs. The 4072 chip has two 4-input gates.

Sometimes, you might not have a standard OR gate. You can build one using other parts instead. You can use NAND or NOR gates to make an OR gate. This is a very helpful trick for builders. You can also make a "wired OR" by joining outputs together. This happens in certain types of transistor processes. It is a clever way to get the same result. Understanding these gates helps us understand how all technology works.

421 words

An OR gate is a fundamental component in digital logic. It is a type of logic gate that performs logical disjunction. This mathematical rule helps computers process information using binary digits, also known as bits. These bits exist in one of two possible states. Scientists and engineers often call these states 1 or 0. They may also use terms like true or false. Other common pairs include high and low, or active and inactive.

OR ANSI Labelled.svg
OR ANSI Labelled.svg

The mechanism of an OR gate is based on its inputs. An OR gate can be built with two or more inputs. The gate follows a specific rule to determine its output. If any of the inputs is 1, the output becomes 1. The output only becomes 0 if every single input is 0. Because of this behavior, the gate is often represented by a plus sign (+). This symbol represents logical addition. You can also think of the gate as finding the maximum value between binary digits. This is different from an AND gate, which finds the minimum value.

OR from NAND.svg
OR from NAND.svg

There are different types of OR gates used in electronics. One specific version is called the inclusive OR gate. This name helps distinguish it from the XOR, or exclusive OR gate. The behavior of an OR gate is very similar to an XOR gate. However, they behave differently when both inputs are 1. In an inclusive OR gate, the output is 1 if both inputs are 1. In an XOR gate, the output would be different. In certain circuits, like a full-adder, these two types are interchangeable. This makes it easy to swap them when using simple integrated circuit chips.

OR from NOR.svg
OR from NOR.svg

Engineers use specific symbols to represent these gates in diagrams. There are two main symbols used today. The first is the American symbol, also known as the ANSI or military symbol. The second is the IEC symbol, which is rectangular and often called the European symbol. The IEC symbol includes a small mark that reads "≥1". This mark indicates that the output is activated by at least one active input. The older DIN symbol is now deprecated and is no longer used. These symbols allow designers to map out complex Boolean circuits.

CMOS 4071 diagram.svg
CMOS 4071 diagram.svg

Hardware engineers can find OR gates in many different integrated circuit families. One common example is the 4071 CMOS chip. This specific chip contains four independent two-input OR gates. Another standard device is the 7432 TTL device. There are many variations of the 7432 that have different internal architectures. For example, the 74LS32 is a low power Schottky version. The 74HC32 is a high speed CMOS version that uses less current. The 74AC32 is an advanced CMOS version with much faster switching speeds. There is also a 74LVC32 version designed for low voltage.

CMOS 4071 diagram.svg
CMOS 4071 diagram.svg

Different chips also offer different numbers of inputs. While most people use two-input gates, other versions exist. The 4075 CMOS chip is a triple 3-input OR gate. The 4072 CMOS chip is a dual 4-input OR gate. When building very large circuits, engineers sometimes use a cascade of NOR and NAND gates. This is because direct implementations of gates with many inputs can be inefficient in CMOS. Using a combination of other gates can be a much more efficient way to build the logic.

OR from NAND.svg
OR from NAND.svg

If a designer does not have a standard OR gate, they can create one using alternatives. You can construct an OR gate using a specific configuration of NAND gates. You can also build one using NOR gates. This flexibility is important because any logic gate can be made from combinations of NAND or NOR gates. Another method is called a wired OR. This happens when several outputs are wired together using active low open collector logic. This arrangement is often found in integrated circuits using N or P-type transistor processes.

Wired or.png
Wired or.png

The OR gate is one of three basic logic gates. The other two are the AND gate and the NOT gate. Together, these three gates can construct any Boolean circuit. This means any function in binary mathematics can be implemented using them. Because they are so fundamental, OR gates are essential to the digital world. They allow the complex logic required for modern technology to function.

Wired or.png
Wired or.png

721 words
🖼️ Images & Media (5)
File:CMOS 4071 diagram.svg
CMOS 4071 diagram.svg
File:OR ANSI Labelled.svg
OR ANSI Labelled.svg
File:OR from NAND.svg
OR from NAND.svg
File:OR from NOR.svg
OR from NOR.svg
File:Wired or.png
Wired or.png
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