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AD9680 and AD9680-1000EBZ

Question asked by pmasek on Jul 23, 2014
Latest reply on Mar 1, 2015 by UmeshJ

Hello everybody,

we would like to evaluate AD9680 1GSps ADC. After few days of reading docs and browsing AD9680-1000EBZ schematics, I'd like to ask you a few questions.


I've found the schematics of AD9680-1000EBZ here:


1. In schematics of AD9680-1000EBZ, page 8, there is an IC labeled U900 without any type description. On other pages (for example page 9), it is referred as AD9526. Nevertheless, I can't find any reference  to this part and it looks like that this part does not exist. Even BOM located in the same FTP directory does not know anything about U900.


2. It looks like this part is not used and all clocks must be supplied externally. Do you have any recommendations for signal generator phase noise? We have Agilent E4426B. Do you think, that this would be sufficient as clock source?


3. Do you have any recommendation for clock synthesizer IC, which would fulfil phase noise requirements for AD9680?


4. It looks like that only possible way to supply clock for AD9680-1000E is analog clock source from RF generator. Using CML or LVDS seems not possible to me with current AD9680-1000EBZ design (proper termination is missing). Is it correct?


5. I've also found some reference to evaluation board AD9680-1250EBZ. From the picture in quick start guide, it looks like this board does not have such limitations as AD9680-1000EBZ. Baluns are supplied externally, so using different clocking (CML or LVDS) should be possible. Do you have any information, if and when this board could be purchased?


Thank you very much and best regards


Petr Masek