Looking at the data sheet for the AD9739, I couldn't find any place that explicitly says which side of the LVDS interface contains the MSB. In other words, is the DB0 pin MSB, or is it DB0?
If I missed that in the datasheet, please let me know where the info is. If it's not there, perhaps you guys can update the datasheet.
I would think the pinout for the AD9737 is designed to use the 11 most significant bits out of the 14 that the AD9739 has but that is not necessarily the way it was done.