I2C MUX 7 Click is a compact add-on board representing a bidirectional selector dedicated to applications with I2C peripheral address conflicts. This board features the PI4MSD5V9547, an octal bidirectional translating multiplexer controlled by the I2C-bus from Texas Instruments. Only one SCL/SDA channel can be selected at a time, determined by the contents of the programmable control register. The board powers up with Channel 0 connected, allowing immediate communication between the controller and downstream devices on that channel. The PI4MSD5V9547 also supports hot insertion, has a low Stand-by current, and has no glitch during the Power-Up sequence. This Click board™ is suitable for a wide range of applications from industrial to medical, communications, and automotive systems.

I2C MUX 7 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

I2C MUX 7 Click as its foundation uses the PI4MSD5V9547, a low voltage octal bidirectional translating multiplexer 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 CH0-CH7, where only one SCL/SDA channel can be selected at a time, determined by the contents of the programmable control register. The board powers up with Channel 0 connected, allowing immediate communication between the controller and downstream devices on that channel.

This Click board™ includes a low dropout linear regulator AP2112 from Diodes Incorporated to provide the 1.8V supply voltage for the PI4MSD5V9547. When power is applied to IC, an internal Power-On Reset (POR) holds the PI4MSD5V9547 in a reset condition until the power supply reaches the POR voltage level. At this point, the reset condition is released, and the PI4MSD5V9547 registers and I2C-bus state machine are initialized to their default states (all zeroes), causing deselection of all channels.

I2C MUX 7 Click communicates with MCU using the standard I2C 2-Wire interface that supports Standard-Mode (100 kHz) and Fast-Mode (400 kHz) operation. The PI4MSD5V9547 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 determine 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. Alongside the internal Power-On Reset (POR) function, this board 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 PI4MSD5V9547 resets its registers alongside with I2C state machine and deselects all channels.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

• Interface: I²C
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 3.3V or 5V
• ON Resistance: 70Ω
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +85°C

• Schematic
• AP2112 Datasheet
• PI4MSD5V9547 Datasheet
• mikroSDK
• GitHub