CAN bus is a communications protocol designed to work in multiplexed communications environments without a host processor. One of the major design challenges that system designers face with CAN, especially when it is used as a field bus in general automation applications is making sure that the communications are robust. Faults or shorts on the transceiver inputs, ESD, and large ground shifts can interfere with the communications. A modern CAN transceiver needs to be able to handle these issues without signal loss.