SLVA787 September 2016 LM8330 , LM8335 , P82B715 , P82B96 , PCA6107 , PCA9306 , PCA9306-Q1 , PCA9515A , PCA9515B , PCA9518 , PCA9534 , PCA9534A , PCA9535 , PCA9536 , PCA9538 , PCA9539 , PCA9543A , PCA9544A , PCA9545A , PCA9546A , PCA9548A , PCA9554 , PCA9554A , PCA9555 , PCA9557 , PCF8574 , PCF8574A , PCF8575 , PCF8575C , TCA4311A , TCA6408A , TCA6416A , TCA6418E , TCA6424A , TCA9509 , TCA9517 , TCA9517A , TCA9534 , TCA9534A , TCA9535 , TCA9538 , TCA9539 , TCA9539-Q1 , TCA9543A , TCA9544A , TCA9545A , TCA9546A , TCA9548A , TCA9554 , TCA9554A , TCA9555 , TCA9617A , TCA9617B , TCA9800 , TCA9801 , TCA9802 , TCA9803
4.1 Pull-Up Resistors
Pull-up resistors need to be connected from the I2C lines to the supply voltage to enable communication. In regards to the capacitive load on the bus, there is a max resistance value associated with the bus capacitance, while the minimum value is determined from the maximum allowed sink current (per I2C slave devices on the bus), offset voltage, and supply voltage.(1)(1)Once the thresholds are determined, the system designer must determine if a stronger pullup is required to account for the capacitance. With a stronger pullup (lower resistance value), more current will be used to make rise times faster for SCL and SDA and ensure that I2C rise time specifications are met. For more information on pull-up resistors on the I2C bus, refer to I2C Bus Pullup Resistor Calculation (SLVA689).
Figure 7. Heavily-Loaded Bus Requiring I2C Buffer 
Figure 8. I2C bus utilizing I2C buffer, which allows more slave devices