I know, but clock rate tends to be a good proxy, especially im cases like this. For a bus like I2C there’s basically two possibilities: 1. You are using a par

I know, but clock rate tends to be a good proxy, especially im cases like this. For a bus like I2C there’s basically two possibilities: 1. You are using a part with a clock rate that extends clock rate over the standard, which means you have very small pull ups on the lines because that is what the datasheet recommends for that speed (thus your rise time gets too short). 2. (And this one is way more likely) you are using I2C to communicate over a long cable.