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TCAN4550: The EOS issue for TCAN4550

Zhang Liang
Genius 5395 points

Part Number: TCAN4550

Hi,

Our end customer feedback there are 4pcs(Total 100pcs) TCAN4550 is failure and they need to know the result;

The below is our schematic diagram and impedance test form, and please advise if there are any error for our design,

Or if we need to add some ESD protect circuit for this design ,thanks.

56b1f70873ab83381e6720c01399de40.jpg

 

b56a3d91facbc6e82125f7f155d6f53c.jpg

Ground impedance.png

  • 0
    TI__Mastermind 37401 points

    Hello Zhang,

    I see there are two different GND nets in the circuit with the protection diodes, filter caps, and termination resistors connected to GND_CAN and the rest of the circuit connected to the other GND. 

    Sudden changes in the current through the CMC can result in large voltage spikes that can exceed the abs max voltage levels of the CANH and CANL pins such as during a short circuit or the application of some offset voltage to the bus.

    Note that the CANH and CANL pins are referenced to the GND pin of the transceiver and if the GND and GND_CAN nets are not the same, there could be some current flow and a potential voltage difference between these two GND nets that may be leading to the device becoming damaged.

    Are they running some form of qualification tests when this failure is being observed?  If so, what are test conditions and do they have any scope plots from their testing?

    Can they test with the two GND nets directly shorted together to see if they have any similar failures?

    Regards,

    Jonathan