CD4051 Single 8-channel Multiplexer/Demultiplexer IC DIP-16 Package

Specifications

• Configuration: 8:1 (Single 8-Channel Multiplexer/Demultiplexer)
• Signal Compatibility: Analog and Digital
• Digital Signal Range: 3V to 20V
• Analog Signal Range: ≤ 20V Peak-to-Peak
• Low ON Resistance (Ron): 125 Ω (Typical) at 15V
• High OFF Resistance: Channel leakage of ±100 pA (Typical)
• Quiescent Power Dissipation: Very low, 0.2 µW (Typical)
• Bandwidth: 20 MHz
• Continuous Current (Max): 10 mA per channel
• Operating Temperature: -55°C to 125°C
• Package Type: 16-Pin DIP (Breadboard friendly)
• Special Feature: Break-Before-Make switching (eliminates channel overlap/shorting)

Applications

• Sensor Arrays: Connect 8 potentiometers, LDRs, or temperature sensors to a single Arduino analog pin.
• Audio Routing: Switch between multiple audio sources or outputs in DIY synthesizers and mixers.
• Home Automation: Expand control lines to manage multiple low-power zones.
• Data Acquisition: Sample multiple test points sequentially in automated testing rigs.

Unlock New Capabilities

• Past Projects: You've likely built basic weather stations or robots using directly connected sensors.
• The Upgrade: The CD4051 unlocks the ability to build massive sensor matrices (like custom MIDI keyboards or full-room environmental monitors) without upgrading to an expensive Arduino Mega.
• Effort/Requirements: Intermediate. You will need 3 digital output pins for addressing, 1 pin for the actual signal, and an understanding of binary counting in your code.

Package Includes:

• 1 x CD4051 Single 8-channel Multiplexer/Demultiplexer IC DIP-16 Package

Frequently Asked Questions (FAQ)

• What is the CD4051 IC used for?
  It is used to route one of eight input signals to a single output, or a single input to one of eight outputs, effectively expanding your microcontroller's pins.
• Can it handle both analog and digital signals?
  Yes, it is a bidirectional analog multiplexer that handles both analog (like audio or sensor voltages) and digital logic signals.
• How many control pins are needed to select a channel?
  You need 3 digital pins (A, B, C) to send a binary address from 000 to 111, selecting one of the 8 channels.
• What is the maximum voltage this IC can handle?
  It can handle up to 20V across VDD and VEE, but logic levels should match your microcontroller.
• What is the difference between VDD, VSS, and VEE?
  VDD is positive power, VSS is digital ground, and VEE is negative analog power. For simple 0-5V circuits, connect VSS and VEE to ground.
• How do I route negative voltages (like AC audio)?
  Supply a negative voltage to VEE (e.g., -5V), positive to VDD (e.g., +5V), and ground VSS. This allows signal swings below 0V.
• Is the CD4051 bidirectional?
  Yes, signals can travel from the 8 channels to the common pin, or from the common pin out to the 8 channels.
• What is the typical ON resistance?
  The typical ON resistance is 125 Ohms when powered at 15V. At 5V, it may be slightly higher.
• Can I communicate via I2C or SPI through this IC?
  No, this is a hardware-level switch, not a digital communication expander like an I/O port multiplier.
• How fast can it switch between channels?
  It has a bandwidth of up to 20 MHz, making it plenty fast for microcontrollers switching at standard speeds.
• What does "Break-Before-Make" switching mean?
  It means the IC completely disconnects the current channel before connecting the next one, preventing two sensors from shorting together during a switch.
• Can I cascade multiple CD4051 ICs?
  Yes! By using the INHIBIT pin, you can chain multiple ICs to expand to 16, 24, or 32 channels.
• What does the INHIBIT pin (Pin 6) do?
  Pulling this pin HIGH turns off all channels, completely disconnecting the common pin from everything.