The PCA9848 is an ultra-low voltage, octal bidirectional translating switch controlled viathe I2C-bus. The SCL/SDA upstream pair fans out to eight downstream pairs, or channels.Any or all SCx/SDx channels can be selected, determined by the programmable controlregister. This feature allows multiple devices with the same I2C-bus address to reside onthe same bus. The switch device can also separate a heavily loaded I2C-bus into separatebus segments, eliminating the need for a bus buffer.

An active LOW reset input allows the PCA9848 to recover from a situation where one ofthe downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resetsthe I2C-bus state machine and deselects all the channels, as does the internalPower-On Reset (POR) function.

The pass gates of the switches are constructed such that the VDD1 pin is used to limit themaximum high voltage which is passed by the PCA9848. This allows the use of differentbus voltages on each channel, so that 0.8 V, 1.8 V, 2.5 V or 3.3 V parts can communicatewithout any additional protection. External pull-up resistors pull the bus up to the desiredvoltage level for each channel. All I/O pins are 3.6 V tolerant.