Phase noise of DDS Filtered Output and unfiltered output

Discussion created by arunverma26 on Dec 9, 2011
Latest reply on Dec 12, 2011 by DSB

I am using AD9912 DDS but have some doubt about the phase noise performance of filtered and unfiltered output. According to datasheet the filtered output of 400 MHz having a phase noise of -122dBc/Hz at 1KHz offset while unfiltered output is having a phase noise of -132dBc/Hz. Why phase noise is degrading so much?


What are the spurious level in both the case (filtered and unfiltered output)?