Q
I used AD9852 as a LO, and found the AD9852's Phase noise is about -135dBc@
1kHz . I want to know whether ADI have products which phase noise can reach
-160dBc@1kHz?
A
The AD9912 is probably the best DDS for phase noise performance. Note, the
phase noise curves in the AD9910 data sheet are Residual measurements. That
means the REF CLK source's phase noise contribution is canceled.
An absolute phase noise measurement would include the REF CLK source's phase
noise contribution. The AD9912 data sheet has absolute phase noise curves in
all the configurations.
The reason I mentioned the residual method is to stress the measurements in the
AD9910 Data sheet assume an ideal REF CLK source.
See Application note attached AN-982: "The Residual Phase Noise Measurement"