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AD9910 Evaluation Board

Question asked by KeithAlexander on Mar 31, 2014
Latest reply on Aug 14, 2014 by Kevin.G



I'm trying to synchronize two of the AD9910 evaluation boards using a similar scheme to CN-0121 except that I am using an ADCLK854 evaluation board to distribute the LVDS clocks and the SYNC_IN signals. I am supplying the 1 GHz Ref Clock from a Crystek 1GHz SAW oscillator rather than an AD9520 as shown in CN-0121. Boards are connected using 18" SMA cables which should have tightly matched delay.


I am using two instances of the control software to try and drive the boards and I am trying to achieve phase synchronization but not succeeding so far. I have "Enable matched latency" and "Autoclear Phase Accumulator" ticked on both the Master and slave boards and have tried various settings with "Auto I/O update" on and off but so far without success. I have also tried supplying "I/O update" externally from a single shot pulse generator to both boards but again without success. Both boards produce the required outputs (at 80 MHz) but phase synchronization is not being achieved.


Here are my questions:


1] Is it possible to produce synchronous outputs from my two boards with the evaluation board software?

2] If it is possible then can you offer some help with the settings or if it is not possible then...

3] Can you suggest a scheme that I can use to get this up and running on the bench with phase synchronization between the boards?


Many thanks