Design with AD9286

Hi, I'm using the AD9286 in a new design and I have a little question about the Vref.

I want to use the SPI comunication to control the Vref.  But do you need to put 1V on this pin or the pin need to be NC.

  • 0
    •  Analog Employees 
    on Aug 10, 2011 9:30 PM

    Hi gtremla,

    If you are planning to use the internal Vref, then allow the pin to float. This will allow you to adjust the Vref via SPI.

    When using an external Vref, then apply the voltage to the pin.When doing so, the SPI is not used to control the Vref.

    Fromt he Datasheet:

    VOLTAGE REFERENCE
    An internal differential voltage reference creates positive and negative reference voltages that define the 1.2 V p-p fixed span of the ADC core. This internal voltage reference can be adjusted by means of SPI control. It can also be driven externally with an off-chip stable reference. See the Memory Map Register Descriptions section for more details.

  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:26 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