PCA9548APW Translating Switch Interface I²C, SMBus 24-TSSOP surface mount

PCA9548APW Translating Switch Interface 24-TSSOP

General description

The PCA9548A is an octal bi-directional translating switch controlled via the I2C-bus. The

SCL/SDA upstream pair fans out to eight downstream pairs, or channels. Any individual

SCx/SDx channel or combination of channels can be selected, determined by the

contents of the programmable control register.

An active LOW reset input allows the PCA9548A 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 and causes all the channels to be deselected as does the internal

Power-on reset function.

The pass gates of the switches are constructed such that the VDD pin can be used to limit

the maximum high voltage which will be passed by the PCA9548A. This allows the use of

different bus voltages on each pair, so that 1.8 V or 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.