• AD9851 - Frequency sweep

    I have my AD9851 connected as shown above with R16 as 100 ohms

    When I sweep from 3MHz to 10MHz. I keep getting noise at around 8MHz frequency at room temperature

    Moreover as the datasheet says it can operate till 85C - but my output becomes noise once…

  • AD9851 DDS output connections and refclock

    I am using the AD9851 in a scalar network analyzer and have some questions about the operation.
    The frequency range I work in is ~2 MHz to 60-70 MHz and I am looking at LPF designs to put on the IOUT pin. I found the filter layout of the evaluation…

  • Help with AD9851

    I designed and printed a PCB that takes in signals from a Raspberry Pi, uses those signals to control the AD9851, amplifies the waveform, and outputs the amplified signal. However, I'm having trouble getting the signal from the AD9851 look like what I…

  • AD9851: RESET input

    A question more about the AD9851. The datasheets mention not much about the
    RESET input. Do I really have to tie it to a processor-pin or can I use a
    simple RC-circuit to reset it on power-up.


    The RC works fine as a POR if you have a…
  • AD9851: frequency senthesis

    We are looking for a frequency synthesis circuit that would allow us to inject
    accurate frequencies into the RF amplifier
    stage of a 173MHz transceiver unit. These frequencies need to be varied (FSK)
    in accordance with a digital data stream…
  • AD9851 DDS


    I have recently ordered for the evaluation board AD9851/FSPCB.

    What else will i require to interface this evaluation board......?

    Do i need to buy any Software tools or Programmer kit also to interface it with my PC....?

  • AD9851 Initialization

    Hi, i am trying to program  DDS AD9851, but i can’t start output frequency generation.

    I use 20 MHz generator as reference clock and 6x multiplier to get 2 MHz output.

    According to the on-line calculator http://designtools.analog.com/dt/dds/ad9851…

  • AD9851 Ringing?

    I am using an AD9851 with +5V supply in an FM signal generator application. The frequency control word is updated serially each 11.77 microseconds to provide the needed FM deviation. The udfcw pulse produces ringing on both rise and fall transitions.…

  • AD9851 DDS Evaluation Board


    We are thinking of using AD9851 DDS IC for our project. We want to generate 1.000010 MHz as output sine wave and the using the on chip comparator to convert this sine wave into square wave. the input clock is either 20 MHz or 30 MHz and in 6 x…

  • ADCLK846 and some AD9851


    Actually I have some AD9851 DDS ICs in my circuit like the below:

    so I need a CMOS clock distributor to feed them simultaneously.

    the supply voltage for AD9851 is +5V bcoz in this condition the maximum output frequency can be achieved as following…