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Question of AD9652 EVB

Question asked by TERRY123 on Apr 6, 2018
Latest reply on Apr 6, 2018 by PMH

Hello, I am using the AD9652.


I have some questionsThis schematic is one sheet of AD9652 EVB.


1. Why using the C17?

 - If 1st pin & 4th pin of T4(each reverse phase) attaches directly to the GND, I think it would be better. Because, On the node of C17(Not GND), small clock signal will be alive in a short time. and this will affect near clock lines.

Then, Is the purpose of using C17 to prevent passing low frequency and to get isolation effect with T4 for 2 clock lines?

I do not know .... these are just my guess.


2. If not using T4 & C17, is it enough to use this board?

    I am curious of the roles of T4 & C17.


3. If i do not use J10 & J11, is it possible removing R87 & R86?


4. please let me know the calculation of impedance matching of this circuit....

My guess is..... only considering CLK_P node , T3//T4 -> 25ohm. so, since R30 & R38 are each 25ohm, these are perfect 25 ohm matching. is that right?




please help me!