Other Parts Discussed in Thread: TCAN337
We have been running a system with several remote modules connected with CAN bus.
All nodes are using TCAN337 transceivers.
All nodes are protected with PESD5V0L2UU,115 TVS diodes tied to chassis (labeled PE in schematic below).
Symptoms: Communication on the bus will stop. After shutting the system down we will measure the impedance from CANH to CANL to be very low (less than 1 ohm). The impedance across the TVS diode will also be very low (less than 1 ohm).
The system will work fine after replacing the Transceiver and TVS diode.
This suggests that the bus was exposed to an impulse large enough to destroy the CAN transceiver and the TVS diode.
The rate of these failures has substantially reduced since adding the TVS diodes, however we still experience failures from time to time.
1) Is the PESD5V0L2UU,115 TVS diode appropriate for this application?
2) What is the best practice for protecting the bus, should we connect the TVS diode to the Chassis (PE) or to the local ground plane?
3) Do you have any additional suggestions for improving the robustness of this system?
Thanks