The 74HC4051, 74HCT4051 is a single-pole octal-throw analog switch (SP8T) suitable for use in analog or digital 8:1 multiplexer/demultiplexer applications. The switch features three digital select inputs (S0, S1 and S2), eight independent inputs/outputs (Yn), a common input/output (Z) and a digital enable input (E). When E is HIGH, the switches are turned off. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

Reduced signal attenuation results in low switching losses
Reduced total harmonic distortion for high quality audio switching
Enable multiplexing of analog sensor signals - reduce number of ADC
Integrated level shifting of control signals interface to lower voltage controllers
Low ON resistance and ON resistance flatness
Low switch leakage
Wide supply voltage
Low input threshold input options
Over-voltage tolerant options
High ESD protection