P82B715 I2C Bus Extender

The P82B715 is a bipolar IC intended for application in I2C bus systems. While retaining all the operating modes and features of the I2C system it permits extension of the practical separation distance between components on the I2C bus by buffering both the data (SDA) and the Clock (SCL) lines. The I2C bus capacitance limit of 400 pF restricts practical Communication distances to a few meters. Using one P82B715 at each end of a long cable (connecting Lx/Ly to Lx/Ly) reduces the cable loading capacitance on the I2C bus by a factor of 10 times and allows the total system capacitance load (all devices, connectors, traces and wires that are connected to the I2C bus) to be around 3000 pF. That means longer cables or lower cost general purpose wiring may be used to connect two separate I2C based systems without worrying about the special voltage levels associated with other I2C bus Buffers Multiple P82B715s CAN be connected together in a star or multi-point architecture by their Lx/Ly ports without limit as long as the total capacitance of the system remains less than about 3000 pF (400 pF or less when referenced to any Sx/Sy connection). In that arrangement the master and/or slave devices are attached to the Sx/Sy port of each P82B715. The P82B715 alone does not support voltage level translation but it simplifies the application of low cost Transistors for this purpose. There is no restriction on interconnecting the Sx/Sy I/Os and those I/Os are also fully compatible with bus Buffers that use voltage level offsets (i.e., PCA9511 PCA9515 Sx/Sy side of P82B96 because it duplicates and transmits the offset voltage.
By NXP Semiconductors