Features 16-Channel Analog/Digital Multiplexer/Demultiplexer CD74HC4067. This chip operates like a rotary switch; it internally routes the common terminal (COM on the diagram, SIG on the board) to one of the 16 channel pins (CHANxx).

It works with digital and analog signals (the voltage cannot be greater than VCC) and the connections operate in any direction. To control it, connect 4 digital outputs to the chip's address selection pins (S0-S3) and send the binary address of the channel you want. This allows you to connect up to 16 sensors to your system using only 5 pins!

You can also use it to transfer serial communication TTL level data to or from multiple devices. For example, you can use it to connect the TX pins of 16 devices to one RX pin on your microcontroller. So you can choose to listen to any of these 16 devices.

If you want bidirectional communication, you can add a second board to route the TX line of the microcontroller to 16 RX lines of devices. By using multiple boards, you can create similar arrangements for I2C, SPI, etc.

The internal switches are bidirectional, support voltages between ground and VCC, have low "on" resistance and low "off" leakage, and to avoid crossover, they perform "break-before-make" switching. The board also disconnects the chip's "enable" pin, which when activated, completely disconnects the common terminal (all switches "off").

• Analog signal input: c0-c15 16 channels
• Analog output: Dig
• Channel control: S0-S3
• Operates from 2V to 6V
• "On" resistance: 70 Ohms @ 4.5V
• 6ns break-before-make @ 4.5V
• Wide operating temperature range: -55C to 125C