• AD9837 exposed pad

    To whom it may concern,

    Should the exposed pad on the AD9837 be connected to analog ground or digital ground?

    The data sheet page 6 says "connect the exposed pad to ground". The EVAL-AD9837SDZ evaluation board page 8 shows analog ground tied to digital…

  • AD9837 amplitude error during phase changement

    Hello all, 

    I still don't understand the amplitude of my signal but it's in an ohter post.

    now I'm facing an other issue. after each phase change, I have a over amplitude on the signal. 

    the signal is take just at the ouput of the DDS.

    I fallow…

  • RE: AD9837 Vout voltage dropt Vs frequency

    I've just check in the document regarding the eval board of AD9837 ans they show an exemple for an output freq a 10KHz, and the output is 596 mVpp. 

    so I really have an issue. I've check the scematics but dont see any différence with mine.…

  • AD9837

    When using the MSB out feature/function, what is the amplitude of the output pulse?  Is it CMOS levels?

    Thanks,

    Tim

  • AD9837 issue...

    Hi.

    I would like to ask a question about the following issues.

    - System

      ; AD9837 evk(Mclk 16Mhz) + control board + AD9837 SDZ(PC Tool)

      ; PC Tool setting  -> Freqreg = 3Mhz, Phase = 0,. Sleep option = Full Power UP, Iout Output = Sinusoidal, Sign Bit…

  • EVAL-AD9837

    Hi, 

    Does the AD9837 eval board have a memory to recall the settings? Will it remember to output the frequency on power cycle? If not, can anyone suggest an alternative chip? 

    Also, what is the output power level of this DDS in KHz frequency range?

    Th…

  • AD9837

    I programmed the AD9837 DDS with the following commands
       0x2100;
       0x4000;
       0x7FFF;
       0xC000;
       0x2000;
    Why does the sinusoid generated have a frequency of about 975Hz?
    I have checked the FSYNC, SCLK and DATA line is correct.

    MCLK = 16MHz

  • AD9837 Phase issue

    Hi,

    I'm having an issue when measuring the phase using the AD9837.

    The AD9837 is running with an 8 MHz MCLK input.

    I configure the AD9837 in a loop like this:

    1. Reset (no sleep)
    2. Write FREQ0/1 19000 Hz
    3. Write PHASE0 = 0
    4. Disable reset, PSEL=PHASE0, FSEL…
  • AD9837 DC offset?

    What kind of DC offset does the 9837 have at the output?

    I don't see it in the data sheet, and I'd like to DC couple the output of the AD9837 to an op amp if I can.

    5V supply, maybe a gain of ... 7 or 8?

    Thank you.


  • AD9837 Triangular Waveform

    Hello,

    I'm planning to use AD9837 to generate triangular waveform. AD9837 output voltage is between 0.037V - 0.645V. I need 0 - 5V 250KHz triangular waveform. So, I will design a opamp circuitry (as below) to generate 0-5V triangular waveform. I searched…