CD4066 Quad Bilateral Switch : Pin Configuration & Its Working

• The CD4066 device is a quad bilateral switch intended for the transmission or multiplexing of an analog or digital signal.
• It exhibits a much lower on-state resistance, which is relatively constant over the full signal-input range.
• The CD4066 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.
• The well of the n-channel device on each switch is tied to either the input (when the switch is on) or to VSS (when the switch is off).
• This configuration eliminates the variation of the switch-transistor threshold voltage with the input signal and, thus, keeps the on-state resistance low over the full operating-signal range.

Pin Diagram

Working of CD4066 Quad Bilateral Switch IC

• The CD4066 IC consists of four switches. It can switch analog signals through digital control.
  An analog signal is applied at the input of the switch.
• If a HIGH or 1 value is fed into the control input, the analog signal will be passed from the input to the output of a switch.
• As it is a bilateral switch, therefore it can operate in both directions forward and reverse.
• Each switch has two pins which can be used as both input and output for switching voltages.
• Pin 14 is connected to the positive terminal of the voltage supply.
• pin 7 is connected to the ground of the circuit.
• When the control input
• HIGH or 1, the terminals of the switch have low impedance between them, and they are said to be in ON condition.
• LOW or 0, the switch is OFF, and the terminal is connected by High impedance.

• The motor remains in an off state when there is no control signal.
• As we apply a logic high control signal to a control pin of switch A, the motor starts to move.
• Therefore, the basic purpose of using this ic is to isolate the control signal from the power signal.
• This IC can also be used as a 4×1 multiplexer.

Applications of CD4066 Quad Bilateral Switch IC

• You can use it as 4 input multiplexer IC.
• Switching and multiplexing of Analog Signals and Digital Signals.
• Sample and Hold circuits.
• Switching of networks.
• Signal Gating, Modulators, Demodulators, Choppers, Commutating Switches.
• Logic Implementation of Transmission-Gates.