AD8302

We intend to use AD8302 for phase measurements. As per the datasheet there is non linearity near 0 degree and 180 degree. For our application, phase diffrence of 0 to 30 degree is vimportant. should we provide an intentional 90 degree phase shift in one input of AD8302 such that the phase difference VPHS comes in the linear region.

or Is there some other technique to solve this issue ?

  • 0
    •  Analog Employees 
    on Mar 2, 2011 6:45 PM

    The operational sweet spot of the AD8302's phase output is indeed 90 degrees. So I think that your idea to add a phase offset such that the AD8302 will see a phase difference that is centered at 90 degrees, is a good one.  The phase offset doesn't need to center you exactly at 90 degrees. As long as you are well away from the 0 deg and 180 deg points, it will be fine.

    It's worth noting that the device also prefers the two input power levels to be as close to one another as possible. Again, they obviously don't need to be equal (it is a gain and phase detector after all). However, it is worthwhile to try some balancing of the average input power levels. The attached article speakes in more detail to the level balancing issue.

  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:18 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.

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    EZ Admin