The CDx4HCx4051 devices are a single 8-channel multiplexer having three binary control inputs, S₀, S₁, and S₂ and an ENABLE input. The three binary signals select 1 of 8 channels to be turned on, and connect one of the 8 inputs to the output.

The CDx4HCx4052 devices are a differential 4-channel multiplexer having two binary control inputs, S₀ and S₁, and an ENABLE input. The two binary input signals select 1 of 4 pairs of channels to be turned on and connect the analog inputs to the outputs.

The CDx4HCx4053 devices are a triple 2-channel multiplexer having three separate digital control inputs, S₀, S₁, and S₂ and an ENABLE input. Each control input selects one of a pair of channels that are connected in a single-pole, double-throw configuration.

When these devices are used as demultiplexers, the CHANNEL IN/OUT terminals are the outputs and the COMMON OUT/IN terminals are the inputs.