The PCA9515 is a BiCMOS integrated circuit intended for application in I2C-bus and SMBus systems. While retaining all the operating modes and features of the I2C-bus system, it permits extension of the I2C-bus by buffering both the data (SDAn) and the clock (SCLn) lines, thus enabling two buses of 400 pF. The I2C-bus capacitance limit of 400 pF restricts the number of devices and bus length.Using the PCA9515 enables the system designer to isolate two halves of a bus, thus moredevices or longer length can be accommodated. It can also be used to run two buses, one at 5 V and the other at 3.3 V or a 400 kHz and 100 kHz bus, where the 100 kHz bus is isolated when 400 kHz operation of the other is required