ADUM3160 problem

Hi,

  

     I started working with ADUM3160 recently. When i first connected it between usb port and a device, it worked fine then after sometime it stopped working. Then again after sometime it started working, i find this very strange and not able find the problem. Please check the circuit in the attached and let me know any changes that has to be made.

Thank you,

Varaprasad

  • 0
    •  Analog Employees 
    on Dec 10, 2015 9:55 PM

    Hello Varaprasad

    That is strange behavior, and I have not seen it in the past.  The ADuM3160 is not an intelligent device, it does not buffer or interpret data, so issues like this usually boil town to problems with power or drivers.  When the part stops working, can you look at the upstream and downstream D+ and D- lines to see if they are in the standard Idle state, which is D+ high and D- low.  If they are both low, or different on the upstream and downstream side, that is a clue.  Also check the voltage levels of the VDD and VBUS lines as well.

    Best Regards,

    MSCantrell

  • Hello MSCantrell,

          The voltage levels thats i observed are as follows:

    When it is working(idle):

    VBUS - 5V

    VDD   - 3.3v

    D+     - 3.3v

    D-      - 0v

    When it is not working:

    VBUS - 5V

    VDD   - 3.3v

    D+     - 0v  or sometimes 2.3v

    D-      - 0v  or sometimes 2.3v

                

                 The power isolator which we are using is capable of providing 200mA @ 5V.


                 Thinking of it, now i recall the board stopped working when i connect to a particular debugger ( i.e. MSP-FET430UIF debugger) and use it for sometime.

     

    Regards,

    Varaprasad.

  • 0
    •  Analog Employees 
    on Dec 16, 2015 3:47 AM

    Hello Varaprasad,

    The power looks OK. When it is not working, the bus looks like the cable has been removed it has a single ended 0.  The 2.3/2.3 is not supposed to ever be an allowed state, that is a single ended 1.   Which side, Upstream or Downstream had these values?  Did they match across the barrier to the other side?  Keep in mind that the isolator separates the bus into two separate USB busses that communicate with each other, so finding a mismatch across the barrier says that it is the isolator that might be causing the issue.

    Also, please verify that the pull-up on the downstream side is present.  It might be integrated into the peripheral controller, or it might be a discrete resistor.  Since the isolator makes two separate bus segments, each segment must have pull-ups and pull-downs.

    Best Regards,

    MSCantrell

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:18 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin