AD9914
Recommended for New Designs
The AD9914 is a direct digital synthesizer (DDS) featuring a 12-bit DAC. The AD9914 uses advanced DDS technology, coupled with an internal high speed,...
Datasheet
AD9914 on Analog.com
I am trying to use DRG mode of dds ad9914. However currently my output is nothing. Can anyone here guide me the correct step order to program the registers in DRG mode?
My current programming sequence:
Master_reset
Wait 20ms
CFR1: VCO calib enable, OSK enable, SDIO input only
IO update
CFR1: OSK enable, SDIO input only
CFR2: DIgitall ramp enable
CFR3: PLL enable
CFR4: PLL calib enable
IO UPdate
CFR4: Default value
Digital ramp lower limit
Digital ramp upperlimit
Rising Digital Ramp Step Size Register
Falling Digital Ramp Step Size Register
Digital Ramp Rate Register
IO Update
Then I change the DRCTL value every time there is a DROVER
My programming sequence is as above and my output is nothing, can anyone with experience tell me the correct programming sequence?
Thanks for replying, I am quite stuck. I do sweep mode, for example currently I do sweep from 100MHz to 150MHz then my output is as in the video. Is there any way I can get a better signal spectrum? I have changed many sweep step size from 0.1MHz to 1MHz and rissing, falling sweep ramp rate from 100ns to 1000ns
Hi HungHo ,
I suggest you try to program the step size and ramp rate to the smallest possible number first to see the sweep slowly. You can try setting these parameters to 1 in binary as shown below:
Also, notices your output seems to be unstable. Try to check the connections of your cables in case there are lose ones.
All the best,
Jules
