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OMAPL137

Angela
Intellectual 595 points
Other Parts Discussed in Thread: OMAP-L137, OMAP-L138

On the OMAP-L137 device, pins F3 and H4 are designated as No Connect. If these pins are connected to ground, is there any harm to device?

  • 0
    TI__Guru* 83985 points

     

    There is a a note in the datasheet

    Important Notice: On the original device pinout (marked "A" in the lower right corner of the package), pins USB0_VSSA33 (H4) and USB0_VSSA (F3) were connected to ground outside the package. For  more robust ESD performance, the USB0 ground references are now connected inside the package on packages marked "B" and the package pins are unconnected. This change will require that any external filter circuits previously referenced to ground at these pins will need to reference the board ground instead.

     

    It is fine if these pins are connected to ground. Inside the package they are now not connected to anything. No harm to the device.


  • 0 in reply to Mukul Bhatnagar
    TI__Expert 4010 points

    OMAP-L137 Datasheet said:
    Important Notice: On the original device pinout (marked "A" in the lower right corner of the package), pins USB0_VSSA33 (H4) and USB0_VSSA (F3) were connected to ground outside the package. For  more robust ESD performance, the USB0 ground references are now connected inside the package on packages marked "B" and the package pins are unconnected. This change will require that any external filter circuits previously referenced to ground at these pins will need to reference the board ground instead.

    Is this also the case for OMAP-L138?  The datasheet does not specify a pin number for USB0_VSSA33 and USB0_VSSA, but the EVM schematic shows these as pins M14 and N16, respectively, and connected to ground.  The datasheet just lists those pins as NC.

    So I guess I have two questions:
    1) Do USB0_VSSA33 and USB0_VSSA have pin numbers?
    2) If they do, does it matter how they're connected?

    Thanks,
    David