The PCA9617A is a CMOS integrated circuit that provides level shifting between low
voltage (0.8 V to 5.5 V) and higher voltage (2.2 V to 5.5 V) Fast-mode Plus (Fm+) I2C-bus
or SMBus applications. While retaining all the operating modes and features of the
I
2C-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 540 pF at 1 MHz or up to 4000 pF at lower speeds. Using the PCA9617A
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 PCA9617A is unpowered.