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ISO1500: Reveiving end seems to stop working

Part Number: ISO1500

Tool/software:

We have been using the ISO1500 chip for a long time now in our products and are just beginning to experience problems with it. It looks like the receiving part of some of the chips have stopped working. When we put Slave devices on the same bus as the master with the defective chip it looks like the master is deforming the signal from the slave device. When we use another device with the same slave device we can see that the signal levels return to normal. I can provide screenshots if necesarry, but it is quite clear on the scope that some of the ISO1500 chips just stop receiving. I am a 100% sure that we are controlling the ISO1500 the way we should. 

  

  • Hello Gido, 

    Thank you for reaching out. This looks like something is pulling the receiver (RXD) pin low.

    I understand that you have used this product for a long time in your design. Has there been any changes to the PCB or microcontroller implementation? How many ISO1500 have had this behavior? 

    Best,
    Andrew

  • Goodmorning Andrew,


    As of right now it's only 5 pieces. They all dropped around the same time. Nothing changed in the implementation. Software also did'nt change. 

    I've checked the driver enable and receiver not enable signals and they are good. I am not sure where to look. I have a feeling that the chips are just deceased. When I changed the chip for a new one. The products started working again and the cumminication as well.

    Best regards,
    Gido 

  • Hello Gido, 

    Is the device part of an in-production design? If it is, are you looking to have the have the failure analyzed by TI?

    One last thing I would recommend checking. Please check to see if the failure follows one of the problem devices. Take a problem device and place them on board that works. Let me know if the issues move to the new board. 

    Best,
    Andrew

  • Hi Andrew,

    Yes the products are already a few years on the market. As stated before only a few have stopped working, but I think it is worth looking into. 

    I will try putting the allegedly faulty chip on a working board and test it. I suspect that the board stops communicating, but I will test it. 

    Best regards,
    Gido

  • Hello Gido, 

    I would recommend submitting a quality return if the failure follows the device. Please follow the recommended actions here Customer returns | Additional information | TI.com.

    Best,
    Andrew

  • I've tried this, but I am not sure where the chips were bought. We outsource production and they also manage inventory. Can I find somewhere what the markings on the chip mean? I can't find that in the datasheet.

    Iv'e got two 1BT APCLG4 and one 1BT APCVG4.

  • Hello Gido, 

    Unfortunately, the package markings won't tell us where the chip was bought from. It would be best to reach out to your Contract Manufacturer and have them submit a quality return on your behalf. 

    Best,
    Andrew