• RE: Setting the phase of an AD9857 upconverter

    Unlike some of our newer generation devices, the AD9857 does not a feature allowing you to clear the phase accumulator. For the AD9857, the only way to guarantee that the accumulator is at zero-phase is to reset the device, but that tends to be problematic…

  • AD9857 output is not unstable in single-tone mode

    AD9857 System Clock fsysclk = 198MHz, configure the AD9857 output 21MHz, 42MHz, 60MHz,the output is very good, using a spectrum analyzer observed spectrum is also very good, but when the frequency is 65MHz , the sine wave distortion , There is a spectrum…

  • My AD9857 output strength is low

    Hi Sir,

        We are using AD9857 in our DVB-T modulator board.  Now it could work, but the output of AD9857 is too low. It is -76dbm.  (Measured using a Spectrum Analyzer. ).  Could you help me? Thanks. The schematic is attached.

  • RE: Help with large spurs in output


    Are you using the AD9857 evaluation board or is this a custom board?

    Best regards,


  • RE: AD9857 Single Input levels ref clock?

    We are using AD9857, so do u know the levels i asked?

    Thank you.

  • RE: dac9857

    hi kevin,

              first off all so much thanks for reply,

    1, we are driving reset as low from fpga.

    2. Bcoz ad9857 configered in single tone mode.i think no need to drive TXEN am i rite?

    can you plz tell me what and all inputs we should give to ad9857 to…

  • AD9857 Iout bad levels

    I have my AD9857 with the next configuration:

    I am using AD9857 with a single REFCLK input of 146.2857MHz with very good CMOS levels.(i have diffclken connected to gnd)

    I have a 2K resistor in pin RSET.

    Iout = 39.93/RSET, So Iout level should be 20mA…

  • How to synchronize multiple AD9857?


    I am trying to work with two of AD9857 DDSs in a synchronised way.

    In order to do that,

    at the same time, REFCLK, DATA etc ,

    I configure these DDSs performing an automatic synchronisation.

    The problem I find is that, after powering up them…

  • RE: AD9857 controlled by an FPGA

    This question has been closed by the EZ team and is assumed answered.
  • AD9857: Producing a sinc wave with DDS

    I want to buy a DDS Model AD9857. In features description is written -
    SIN(x)/x correction (inverse SINC function)
    Does that mean that I can also produce a sinc signal with this DDS?


    No - there is a sibc filter correction for the DAC…