AnsweredAssumed Answered

AD5930 and Saw Sweep

Question asked by bvo on Dec 21, 2010
Latest reply on Jun 5, 2015 by musach

Hi,

 

 

I'm doing some application with AD5930. I'm trying to do a frequency sweep from 115kHz to 125 kHz in a saw-sweep mode. Frequency must rise from 115k to 125k and then again from 115 to 125k repeatedly.

 

For now I successfully made a triangular-sweep, so frequency rise from 115k to 125k and then falling from 125k to 115k. But this is not what I want. So I set bit D4 in control register to 1, but nothing changed! Frequency sweep stay in triangular mode.

 

I searched all over the internet but I can't found nothing similar

 

 

Here is my current configuration for AD5930:

 

    // CTRL pin 0

 

    //Control reg bits
    spiWrite(0x0E9F);  // 0000 1110 1001 1111
   
    //fstart
    spiWrite(0xC80B); //MSB
    spiWrite(0xD009); //LSB
   
    //Δf
    spiWrite(0x214F);   
     spiWrite(0x3000);   
   
    //Nincr
    spiWrite(0x100A);
   
    //tint
    spiWrite(0x6190);

 

    // CTRL pin 1

 

 

 

What am I doing wrong or what I may have forgotten?

 

Please for advice. Thank you.

Outcomes