AnsweredAssumed Answered

AD9959 very low power  frequency output

Question asked by anurag250891 on Jun 28, 2018
Latest reply on Jul 11, 2018 by mcee

Hello Everyone,


I am working on AD9959 DDS board (china made). I have interfaced it with microcontroller successfully and I was able to get all the four channel outputs independently with different frequency output.


But suddenly something went wrong and i lost all the four channel output from the device. 

While testing the device i checked that all the SPI signals including the sync clock (125 MHz) is properly visible on the oscilloscope and all the supply voltages are also proper on the device and Even the device is also getting programmed properly. 


So to verify the coding part I just wrote fixed frequency and also varied the frequency through the program on all the channels and I see the output on the spectrum but the output power was very low and signal was barely visible. I am trying to figure out the problem but still no progress. 


I tried to check the output directly on the CH0_IOUT pin through oscilloscope but signal power was very low so could not see but i could see it on spectrum and it was barely visible. I have also attached the schematic of the board(AD9959). with this query.