TheCD4066 device is a quad bilateral switch intended for the transmission or multiplexing of an a log or digital signals.
It is pin-for-pin compatible with the CD4016B device, but exhibits a much lower on-state resistance. In addition, the on-state resistance is relatively constant over the full signal-input range.
The CD4066 device consists of four bilateral switches, each with independent controls. Both the p and the n devices in a given switch are biased on or off simultaneously by the control signal.