74HC4051: Analog Switch for Multiplexer-Demultiplexer
Signal control through switches is a key part of many electronics projects. A project may need to manage many signals into one output or route multiple signals into multiple outputs. Switches that manage many signals into one output are called multiplexers, while switches that route multiple signals into multiple outputs are called demultiplexers. Some switches, like the 74HC4051, can perform both of these functions. Its function relies on the level of voltage present in each of its inputs, a common mechanism in combined multiplexer/demultiplexer switches.