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AD9915 Current Sweep Frequency

Question asked by CHuffine on Oct 18, 2017
Latest reply on Oct 20, 2017 by mcee

I am using the AD9915 to create a frequency chirp, and I need to determine the active frequency at any point in the sweep determined by a trigger. As far as I have found, there is no way to determine the current internal state of the DRG, and I will be forced to determine the frequency externally.

What I am looking for is either a way to find this value internally, or the best method to track the state externally.

The concept that seems most promising is to use a counter with SYNC_CLK and DRCTL (being used to begin the sweep) and performing a math operation on the count to estimate the frequency. Another question that arises from this relates to the start trigger; based on my work so far, there appears to be a constant delay between DRCTL being triggered and the DRG beginning the sweep.  

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