AD9514 synchronization

I feed AD9514 CLK input from AD9517 output. SYNCB pin of AD9514 is tied with CSB pin of AD9517. After AD9517 callibration finish I read state of AD9517 register once more to synchronize AD9514 outputs, but result is sporadic. What may be a reason of this? SPI CLK frequency is 1.5MHz, CLK signal from AD9517 to AD9514 CLK input is100MHz.

  • 0
    •  Analog Employees 
    on May 27, 2015 9:38 PM

    Hi Alexander,

    > I feed AD9514 CLK input from AD9517 output. SYNCB pin of AD9514 is tied with CSB

    > pin of AD9517. After AD9517 calibration finish I read state of AD9517 register once

    > more to synchronize AD9514 outputs, but result is sporadic.

    I puzzled why you would tie the SYNCB pin to the CSB pin. The CSB pin has no value as a synchronization pin, as as you say, your results will be unpredictable.

    If you want to sync the AD9514 to the AD9517, it seems to me that the SYNCB pins of the AD9517 and AD9514 should be tied together, with some means of delaying the sync signals between the two devices. The reason for the delay is that you may need to account for the prop delay through the AD9514.

    -Paul Kern

  • pkern написал(а):

    Hi Alexander,

    > I feed AD9514 CLK input from AD9517 output. SYNCB pin of AD9514 is tied with CSB

    > pin of AD9517. After AD9517 calibration finish I read state of AD9517 register once

    > more to synchronize AD9514 outputs, but result is sporadic.

    I puzzled why you would tie the SYNCB pin to the CSB pin. The CSB pin has no value as a synchronization pin, as as you say, your results will be unpredictable.

    If you want to sync the AD9514 to the AD9517, it seems to me that the SYNCB pins of the AD9517 and AD9514 should be tied together, with some means of delaying the sync signals between the two devices. The reason for the delay is that you may need to account for the prop delay through the AD9514.

    -Paul Kern

    Dear Paul.

    I want set the OUT1 and OUT2 of AD9514 clocking in synchronicity (phase shift = 0). Because I have not free control signal for driving SYNCB pin of AD9514 I tied  it with CSB pin of AD9517. Then each AD9517 SPI transaction will activate synchronization cycle of AD9514. The fragment of scheme is shown

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:03 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

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