I'm helping to redesign the CAN bus of an electric car, and we're interested in achieving higher data rates of up to 8 Mbit/s. We have a transceiver selected, a CMC to reduce inductively coupled noise, and we are now looking at termination schemes as the next step.
We came across the split termination scheme which, according to section 4.5.2 of this TI document and various other sources, can help stabilize the common-mode bus voltage and filter out high frequency noise. A typical value for the center tap capacitor is listed as 4.7 nF for a data rate of 1 Mbit/s if I'm understanding correctly. Is the relationship as simple as solving for the capacitance with the given equation? If so a value of 620 pF would be suitable for 8 Mbit/s, but the common-mode voltage itself shouldn't be changing at such a high frequency should it? Would this value work?