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SN65HVD230 Issue

ET3D
Prodigy 120 points
Other Parts Discussed in Thread: SN65HVD230, SN65HVD233

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 So I have been using the SN65HVD230 CAN transceiver, and lately I’ve been having some issues with these CAN transceiver failing either from being first populated onto the board and never working or when it’s out there in field and the CAN communication will no longer work. 

 

I tried troubleshooting it and this is what happens. When I send the data communication to the transceiver, the CANH line is stuck high, while CANL is active and you can see the data being sent. When replacing the IC with another one, the board starts working again. What can be the cause of this? Thanks

 

Here is my design

  • 0
    TI__Mastermind 28265 points

    You said "lately" you have been having some trouble!

    How much lately? How long have you been using this device without trouble? weeks, months, years?

    I try to find out whether this is a device issue or whether you changed something in the application. Your schematic looks correct.

    Have you been changing your distributor lately ?

    regards,

    Thomas Kugelstadt

  • 0 in reply to Thomas Kugelstadt
    Prodigy 120 points

    Hi Thomas,

     

    Thanks for the quick reply.  I take back the word "lately".  What is happening is this, we have two different types of incidents that are occuring.

     

    Incident #1 consists of the board house populating these chips onto our boards and when the time comes to test the CAN functionality out, CAN doesn't work.  We have troubleshoot it down to a point where CANH would be tied high for the whole time while CANL had datat being sent.  When replacing the IC, the board works again.

     

    Incident #2 consists of a board that is functioning properly.  While CAN is communicating, all of a sudden CAN communication would stop and the board would no longer communicate via CAN.  I really haven't been able to troubleshoot this incident and is very hard to reproduce.  Would you have any idea on why this occur?

     

    I am currently checking with our board house to see if they have been using multiple distributors.

     

    Here are the lot #s on the two different chips: HV230Q 03M AVQ8G4 and HV230Q 01M AGQ5.  I do not know if this will help out or not, but hopefully you are able to find out if there was a bad batch of chips or not.  Thanks

     

    David

  • 0 in reply to ET3D
    Prodigy 120 points

    Also to protect the CAN lines, what should my diode values be?  I currently have them at 22V.  Thanks.

  • 0 in reply to ET3D
    TI__Mastermind 28265 points

    David,

    the SMAJ30CA in your schematic has a clamp voltage of some 48V max, more than twice the 22V you quoted. The HVD230 maximum ratings for line voltages are only -4V to +16V. I suggest to look on the SEMTECH site for transient supressors. I have attached a TClamp device, often used in Ethernet applications. Another favored device is the SM712 TVS for RS485 links, which is also used for 5V CAN busses.

    The TClamp is designed for 3.3V application though. In both cases the clamp voltages are around 20V. During the clamping process, the clamp voltage is still capable of destroying a transceiver if the clamp voltage is higher than the max. ratings of the bus voltage. However, at 20 to 22V you are much closer to the HVD230 max. ratings. A common approch to limit the current into the transceiver bus during clamping is to insert a 10 ohms industrial MELF resistor (i.e. from Vishay) into each bus line (CANH and CANL) close to the transceiver (after the TVS).

    Let me know how this works, but this solution should be solid.

    I will be sending you a Sample Return form tomorrow for our FA lab, just in case everything else fails and you want to send the sample for analysis.

    Good luck,,

    Thomas.   

    tclamp3302n.pdf
  • 0 in reply to Thomas Kugelstadt
    TI__Mastermind 28265 points

    David,

    I have attached the sample return request form.

    Please fill out the form and send samples and form to the following address:

    Attention: Halimah Yusof

    Texas Instruments Incorporated

    12500 TI Boulevard, MS 8701

    Dallas, Texas 75243

    (214) 480-4836

    Thanks & regards,

    Thomas

    Device_Failure_Verification_Request_Form.doc
  • 0 in reply to Thomas Kugelstadt
    Prodigy 210 points

    I second that. 

    I have had many issues with this chip. For me the chip worked in our testing and failed in the field. I have not done any detailed analysis of the behaviour  of the chip when it fails. When the chip is replaced the unit starts to communicate. 

    I have switched to SN65HVD233 and 235, these have higher bus fault voltage range (+/-30). So far these seem to work for me but recently I heard of a unit failure and I am waiting to get the unit back from field for analysis.

     

    The environment my boards are subjected to is very harsh (electrically).