Tca9548A – How it works
The I2C multiplexer breakout board works and communicates thanks to the TCA9548A chip by Texas Instruments. The TCA9548A chip enables communication between a microcontroller and up to eight I2C devices with identical addresses. This is achieved by multiplexing the I2C bus, allowing the microcontroller to communicate with one device at a time by selecting its corresponding channel.
Datasheet
For an in-depth look at technical specifications, refer to the official TCA9548A Datasheet:
TCA9548A Datasheet
Detailed technical documentation for the TCA9548A chip
Multiplexing Functionality
The TCA9548A works as a switch for I2C communication. It has:
- One main I2C bus (SDA/SCL) connected to the microcontroller.
- Eight independent channels (SDA0-SDA7 and SCL0-SCL7) for connecting I2C devices.
Through I2C commands the TCA9548A simplifies complex I2C setups by enabling multiple devices with identical addresses to coexist on a single bus, you can activate a specific channel enabling communication with the device connected to that channel while isolating the others. This ensures no address conflicts between devices with identical I2C addresses. The default I2C address of the TCA9548A is 0x70, but it can be adjusted using the A0, A1, and A2 pins where each combination is listed on the hardware details page. Up to eight multiplexers can be connected to a single bus, allowing communication with up to 64 devices.
Interrupt Handling
The TCA9548A supports interrupt functionality:
- Devices connected to individual channels can signal interrupts via their respective SDA lines.
- The multiplexer passes these interrupts through its main SDA line, allowing the microcontroller to detect them.