PCA9547BS,118

The PCA9547 is an octal bidirectional translating multiplexer controlled by the I2C-bus.
The SCL/SDA upstream pair fans out to eight downstream pairs, or channels. Only one
SCx/SDx channel can be selected at a time, determined by the contents of the
programmable control register. The device powers up with Channel 0 connected, allowing
immediate communication between the master and downstream devices on that channel.
An active LOW reset input allows the PCA9547 to recover from a situation where one of
the downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets
the I2C-bus state machine causing all the channels to be deselected, except Channel 0 so
that the master can regain control of the bus.
The pass gates of the multiplexers are constructed such that the VDD pin can be used to
limit the maximum high voltage which will be passed by the PCA9547. This allows the use
of different bus voltages on each pair, so that 1.8 V, 2.5 V, or 3.3 V parts can communicate
with 5 V parts without any additional protection. External pull-up resistors pull the bus up
to the desired voltage level for each channel. All I/O pins are 5 V tolerant.