40 reference clock for AD9913 DDS


According to the datasheet of AD9913: 

"When using a crystal at the REF_CLK input, the resonant frequency should be approximately 25 MHz."

But the only source that I have in the system is a 40 MHZ crystal oscillator. How can can that be used as the reference clock for AD9913?

Thank you 

  • +1
    •  Analog Employees 
    on Jan 22, 2021 7:37 AM 1 month ago


    There is no minimum or maximum frequency value for the external crystal according to the data sheet but the typical 25MHz value is required as the circuitry within the device is tuned to this specific frequency. Using different frequency value will not guarantee the same performance indicated on the data sheet.

    Best regards,