ADF5610 Divider Noise Floor

Question

Hello, 
 What is the noise floor of the divider used in the ADF5610? 
 I do not see any phase noise plots in the datasheet with the divider enabled. I also do not see the divider noise floor defined in the specifications table. 
 I know there will be a 20*log(N) improvement at close offsets using the divider, but at some point the divider noise floor will be dominant. I&rsquo;m interested in that value in dBc/Hz. 
 Thanks, 
 John

ADIApproved · Accepted Answer

Hi, 
 Divider output noise floor is worse than RFOUT and noise floor values for different frequencies are given below. 
 RFOUT has the best noise floor as would be expected (<= -160dBc/Hz) 
 PDIVOUT = 8 GHz (8 GHz div by 1) = -153 dBc/Hz due to noise floor of the mux. 
 PDIVOUT = 14.6 GHz (14.6 GHz div by 1) = -152 dBc/Hz 
 PDIVOUT = 7 GHz (14.0GHz div by 2) = -150 dBc/Hz 
 
 Regards, 
 Kudret)

kieranb · Answer

Hi Allen, 
 Can you share your phase noise floor specs for the output frequency at 700MHz? 
 If you could provide any other relevant info such as reference frequency, loop filter bandwidth etc. 
 We may need to recommend another part from our portfolio for this. 
 Thanks, 
 Kieran

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Products Mentioned

ADF5610 Divider Noise Floor