Truth table for a buffer

A buffer has only a single input and a single output with behavior that is the opposite of an NOT gate. It simply passes its input, unchanged, to its output. In a boolean logic simulator, a buffer is mainly used to increase propagation delay. In a real-world circuit, a buffer can be used to amplify a signal if its current is too weak.

The truth table for a buffer appears to the right.


Each of the symbols below can be used to represent a buffer. There are multiple international standards defined, and one may preferred over the other in your region of the world.

ANSI /IEEE Buffer symbolIEC Buffer symbol

Live Example

Try the following interactive example to see for yourself how a buffer behaves.

Further Reading

To learn more, check out the following external resources:

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