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TCAN1463-Q1: CAN Bus line isolation

Part Number: TCAN1463-Q1
Other Parts Discussed in Thread: ISO1042, , TCAN1044A-Q1, TCAN1043H-Q1, TCAN1042H-Q1

Hello,

My customer has some questions about the CAN interface isolation.

Q1. When CAN communication is connected as shown below, is there a solution that can isolate the red area below?

Q2. When the CAN bus line is isolated as shown in the picture above, the left and right sides use different grounds. In this case, will there be any problem with CAN communication?

Q3. Among TI's CAN transceiver products, is there a separate CAN transceiver product optimized for automobiles that use 48V power?

Thank you.

JH

  • JH,

    Generally there isn't too much of a need for isolation in this manner for systems that use CAN as the transceivers have the capability to handle ground shifts or faults that are possible within a system. That being said, we do have isolated CAN driver like ISO1042 which can handle non-SIC communication in an isolated manner.

    For Q2, note that there is a specified GND shift that is allowed in CAN systems. If using a TCAN1463-Q1, for example, the signal would need to be within the transceiver's ±12 V common-mode range to be properly interpreted.

    Regarding Q3, we are actively evaluating the use of CAN transceivers in 48 V systems. It depends on the requirements of the 48 V system. For example, a high-standoff device like TCAN1042H-Q1 or TCAN1043H-Q1 can meet the needs outlined in ISO 21780, which is one existing standard that governs the development of 48 V automotive systems. These systems require that communication lines be able to withstand a DC short of 52 V and a VSUP up to 70 V, which these devices can meet. The TCAN1044A-Q1 could be usable in systems depending on the fault requirements that are needed, since it is not exposed directly to VBAT/VSUP. We will also continue to keep our portfolio up-to-date as the market needs shift toward 48 V systems in the future.

    Best,

    Danny