I2C MUX 3 Click is a compact add-on board that contains eight bidirectional translating switches dedicated for applications with I2C peripheral address conflicts. This board features the TCA9548APWR, a low voltage 8-channel I2C bus switch with an active-low reset input from Texas Instruments. It possesses three programmable address pins that allow up to eight TCA9548APWR devices, supports hot insertion, has a low Stand-by current, and no glitch during Power-Up with all switch channels deselected. This Click board™ is suitable to work with I2C interfaces for applications such as fault isolation, address conflict, level translation, or broadcast communication (servers, routers...).

I2C MUX 3 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

I2C MUX 3 Click is based on the TCA9548APWR, a low voltage eight bidirectional translating switches with an active-low reset input controlled through the I2C serial interface from Texas Instruments. The controller SCL/SDA signal pair is directed to eight channels of peripheral devices, SC0/SD0-SC7/SD7, where any individual downstream channel can be selected as well as any combination of the eight channels. It features I2C control using a single 8-bit control register in which each bit controls the enabling and disabling of one of the corresponding 8 switch channels for I2C data flow.

This Click board™ includes a low dropout linear regulator AP7331 from Diodes Incorporated to provide the 2.45V supply voltage for the TCA9548APWR. When the TCA9548APWR is turned on for the first time or anytime the device needs to be reset by cycling the power supply, which means that the Power-On reset requirements must be followed to ensure the I2C bus logic is initialized properly. Additionally, if communication on the I2C bus enters a fault state, the TCA9548APWR can be reset to resume normal operation using the RST pin feature or by a Power-On reset which results from cycling power to the device.

I2C MUX 3 Click communicates with MCU using the standard I2C 2-Wire interface that supports Standard-Mode (100 kHz) and Fast-Mode (400 kHz) operation. The TCA9548APWR has a 7-bit peripheral address with the first five MSBs fixed to 1110. The address pins A0, A1 and A2 are programmed by the user and determines the value of the last three LSBs of the peripheral address which can be selected by onboard SMD jumpers labeled as ADDR SEL allowing selection of the peripheral address LSBs. It also has an active-low reset signal routed on the RST pin of the mikroBUS™ socket used to recover from a bus-fault condition. When this signal is asserted low the TCA9548APWR resets its registers alongside with I2C state machine and deselects all channels.

This Click board™ is designed to be operated with both 3.3V and 5V logic voltage levels that can be selected via VCC SEL jumper. This allows for both 3.3V and 5V capable MCUs to use the I2C communication lines properly. More information about the TCA9548APWR can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy to use functions and a usage example that may be used as a reference for further development.

• Interface: I²C
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 3.3V or 5V
• Supply Voltage: Min. -0.5V, Max. 7V
• Maximum Output Current: -25mA
• Maximum Frequency: 400 kHz
• Operating Temperature Range: Min. -40°C, Max. +125°C

• Schematic
• AP7331 Datasheet
• TCA9548A Datasheet
• mikroSDK
• GitHub