How does galvanic isolation affect my network?

ANSWER

Galvanic isolation improves the stability and quality of the CAN signal. It protects the CAN controller—and therefore the device—from damage caused by overvoltage that may result from electromagnetic interference or from different electrical potentials in networks where devices use separate power supplies.

However, galvanic isolation is an additional component in the communication path between the CAN controller and the CAN bus. Even high‑speed isolation components introduce propagation delays in the range of approximately 50 ns. This corresponds roughly to the signal propagation time of 10 meters of cable and must be considered when calculating the maximum allowable cable length.

In most cases, though, the advantages of galvanic isolation outweigh the disadvantages.