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. The TCAN340x-Q1 family has the recessive bias voltage set to 1.9V. This is intentional to match the common mode of recessive output with the common mode of dominant output signal from TCAN340x-Q1. Furthermore, TCAN340x-Q1 has special design techniques for optimum EMC performance in a heterogeneous bus consisting of TCAN340x-Q1 and 5V CAN transceivers.