APPARATUS AND SYSTEM FOR AN ACTIVE STAR/STUB/RING CONTROLLER AREA NETWORK PHYSICAL LAYER TRANSCEIVER

摘要

A controller area network (CAN) node comprises an internal high differential bus line (CANH) and an internal low differential bus line (CANL). The CAN node further comprises a receiver (RXD) comparator coupled to both the internal CANH and the internal CANL that outputs an internal RXD signal. The CAN node further comprises an RXD dominant time out (DTO) circuit. The RXD DTO circuit includes: a) an RXD dominant transition detector coupled to an output of the RXD comparator; b) a timer triggered by the RXD dominant transition detector detecting a dominant RXD transition; c) an RXD dominant timer comparator that is coupled to an output of the timer which compares an output of the timer to a selected value; d) an internal RXD dominant signal is changed to an RXD DTO recessive signal after a selected time interval has lapsed and can include a fault output to signal this fault condition.