11.3.3 Common-Mode Signal and EMC Performance

A common-mode signal is an average voltage of the two signal wires that the differential receiver rejects. The common-mode signal comes from the CAN driver, ground noise, and coupled bus noise. Since the bias voltage of the recessive state of the device is dependent on V_CC, any noise present or variation of V_CC has an effect on this bias voltage seen by the bus. The TCAN33x family has the recessive bias voltage set higher than 0.5 x V_CC to match common mode in recessive mode to dominant mode. This results in superior EMC performance.