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AD9833 Output Voltage drop

Question asked by paat on May 7, 2015
Latest reply on May 7, 2015 by paat

Hi everyone,

I am using the AD9833 on a custom designed PCB board to generate a sine signal in various frequencies.

My desired frequencies are in the range of 1khz up to 10khz.

I am using a 50Mhz external oscillator, because i had no 25Mhz clock.

Somehow the output voltage decreases with increasing frequencies.


Here is my schematic:


And here are some sample measurements:

1.5khz          735mVpp

3khz          690mVpp

6k hz          530mVpp


Any advice or theory why the voltage drops?

I guess it's either due to the clock or the connected GNDs.

Thanks in advanced!