Level Translating I2C Bus Repeater, 0.9V to 5.5V, TSSOP-8 - 

The PCA9517ADP is a CMOS Integrated Circuit that provides level shifting between low voltage (down to 0.9V) and higher voltage (2.7V to 5.5V) I²C-bus or SMBus applications. While retaining all the operating modes and features of the I²C-bus system during the level shifts, it also permits extension of the I²C-bus by providing bidirectional buffering for both the data (SDA) and the clock (SCL) lines, thus enabling two buses of 400pF. Using the PCA9517A enables the system designer to isolate two halves of a bus for both voltage and capacitance. The SDA and SCL pins are overvoltage tolerant and are high-impedance when the PCA9517A is unpowered. The 2.7V to 5.5V bus port B drivers behave much like the drivers on the PCA9515A device, while the adjustable voltage bus port A drivers drive more current and eliminate the static offset voltage. This results in a low on the port B translating into a nearly 0V low on the port A which accommodates smaller voltage swings of lower voltage logic.