TCA9548A I2C Multiplexer

The TCA9548A I2C multiplexer lets you connect up to 8 same-address I2C devices to one microcontroller. Select channels by writing a byte to address 0x70 (adjustable to 0x77). Stack up to 8 multiplexers for 64 devices.

Found the perfect I2C sensor, then hit the classic problem: the address is fixed, so you can’t use two of the same sensors on the same SDA/SCL lines. That’s exactly what the TCA9548A 1-to-8 I2C multiplexer is for.

This handy Adafruit board lets you connect up to 8 I2C devices with the same address to a single microcontroller by acting as a gatekeeper. You simply select which channel you want to talk to, and the multiplexer routes all I2C traffic to that set of pins.

The multiplexer itself sits at I2C address 0x70, but it can be changed to any address from 0x70 to 0x77. To switch channels, you write a single byte to choose the output port, and from then on, any I2C packets are sent to that selected channel. In theory, you can run up to 8 multiplexers at addresses 0x70–0x77, giving you control of up to 64 same-address I2C devices.

As with Adafruit breakouts, the chip is mounted on a breadboard-friendly board with the supporting components needed to make wiring simple. You’ll need to solder on the included header so it can plug into a solderless breadboard. The TCA9548A is 3V and 5V compliant, so it works with either logic level.

Please note, You may get an off-white or black JST connector.

Specifications

• Weight: 1.8g
• Dimensions: 30.6mm x 17.6mm x 2.7mm
• Selectable I2C address 0x70-0x77

Resources

• Documents

Package Contents

• 1x TCA9548A I2C Multiplexer
• 2x 16-pin headers