Since the I2C protocol limits the allowable bus capacitance to 400pF (for Standard and Fast Mode) or 550pF (for Fast Mode+), similar requirements will need to be implemented on the TXG8122-Q1.
There are two main factors that determine I2C bus capacitance: 1) Input cap present on SDA and SCL, 2) cable capacitance.
Input Capacitance: The input cap from SDA and SCL is 5pF (typ). This value is very minor when compared to the cable capacitance, especially you if are communicating with one device. However, the input capacitance will continue to increase as more device (or peripherals) are added to the I2C bus.
Cable Capacitance: A good rule of thumb for cable capacitance is 1pF/cm. If Standard Mode is used, the max cable length 4 meters (or 13 feet).
To support higher capacitance loading, it’s recommend to place TXG8122-Q1 Side 2 (SDA2 & SCL2) with all other I2C peripherals.
