Post Go back to editing

ADF4360-7 Locking Problem and External Inductor Issue


Hi,

I have questions regarding PLL locking and external inductors.

I am trying to get a constant RF output from the device. 
I use ADF4360-x Evaluation Software to obtain register values and send them via a microcontroller.
I use ADIsimPLL to obtain the schematic.


In my case, I want to have 500 MHz output signal. 
I followed the schematics that Eval. Board and ADIsimPLL suggest.
The ADIsimPLL schematic and ADF4360 Eval. software output and my schematic' pictures are attached.

The other issue is external inductors. ADIsimPLL suggests me to use 3.15nH however, ADF4360-7 datasheet says that I should use around 12nH to get 500 MHz at the output. (page 22, Figure 24. Output Center Frequency vs. External Inductor Value)

Please note that for the loop filter I couldn't find the exact values that ADIsimPLL suggests on the market.
Instead of 282pF, I use 270pF
     "       "   13.6K, "  "      13.3K
     "       "   58.3pF, " "      56pF

I could not get ADF4360-7 locked.

What am I missing ?



Thanks in advance.



Image alignment
[edited by: FrequencyModulator at 1:46 AM (GMT 0) on 24 Apr 2020]