ADRF6703 Reference Input

Hello.

I have a question about the conditioning of the reference input to the ADRF6703. My problem is as follows.

The datasheet states that the proper conditioning for this input is ac-coupled generator output with voltage swing of 1V p-p. It mentions something about its input resistance being high. However, the details are extremely scarce, if not non-existent. The absolute maximum ratings section point out that the minimum voltage that can be applied to the reference input is approximately 0V.

Could anyone please provide me with some detailed information about this pin's internal circuitry or the proper way to handle it? Should the waveform be sine or pulse? What's the reason for mandatory ac-coupling and how does it tie in with absolute maximum ratings? Is there some circuitry inside the chip that pushes the input signal's Dc-bias up to make sure it's withing the limits?

Thank you very much in advance.

  • 0
    •  Analog Employees 
    on Mar 23, 2016 7:33 PM

    Hi Sergey,

    • Absolute maximum ratings are in terms of DC (no ac-coupling) and are not intended for typical use. They are the maximum temporary stress limits.
    • A square-wave would provide the best phase noise due to the higher slew rate compared to a sine-wave. A sine-wave may give better spurious performance however (the square wave would contain some harmonics).
    • Many of our devices include an internal bias generator to simplify the interface for our customers like this.

    Regards,

    Liam

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:24 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