In EV-ADF4159EB1Z, the following spurious was confirmed. (span is 1MHz)
Is this an unavoidable spurious noise?Or if there is a cause, can we avoid this spurious noise?
The conditions are as follows.
P/N : EV-ADF4159EB1ZReference frequency : 100MHzOutput frequency : 12GHzRegister setting : R0 :300F0800 R1 :00000001 R2 :0001050A R3 :010300C3 R4-1:00180104 R4-2:00180144 R5-1:00000005 R5-2:00800005 R6-1:00000006 R6-2:00800006 R7 :00000007
Using the GUI of the EV-ADF4159SD1Z, can you please send me a snap shot of the GUI using the configuration as per the register list above thanks Brigid.
Thank you for your reply.
The register setting described earlier was the register setting of the board designed by the customer.Please forget this once.
The following is the EV-ADF4159EB1 register setting information.
I dont see a constant spur like you show, however there is a pulsating spur showing which looks to be due to the SDM, can you try enabling the SD test mode that turns off the SDM when Frac = 0 ? ,
Double click on the Analog Devices logo to see the test modes , and change the SD Test modes to SD disabled with FRAC =0.
The eval board is configured for a wide loop bandwidth for optimum ramp performance, however for best spur performance, you need to reduce the loop bandwidth in order to attenuate the SDM noise, regards Brigid.