I2C Bus Pull-up Resistors

If the maximum permitted rise time for both the serial data (SDA) and serial clock (SCL) line of an I2C bus is 1000ns, the load capacitance is 200pF, and the minimum logic high voltage is 3.3V. The maximum acceptable values of the pull-up resistors to be used is calculated as:

Where:
t = Maximum time
C = Load Capacitance
Vth = Minimum logic high voltage
Vcc = Supply Voltage
Vo = Bus line Output Voltage

Therefore, choose a 4.7KΩ resistor as the value of resistor pull-up