TCA6408A: I2C falling time of TCA6408A

Hey Teresa,

The fall time you are specifying is from an old I2C version. It does NOT mean if you have a faster fall time than this that our device will not work. It is included to specify the system level requirement to be within I2C standard with our device. The new I2C standard uses different input fall times based on Vcc.

If you want to make the fall time slower, you can either add more bus capacitance or add a series resistor in front of the device that is not meeting the fall time spec. Having a faster than minimum fall time will likely not affect signal integrity but may indicate the device is outside of I2C spec (breaking this part of the spec will not harm anything).

Having a fast fall time may introduce undershoots, which may be why this spec was introduced in the I2C standard.

Thanks,

-Bobby