Part Number:LMX2594
Hi Dean, Noel
About two weeks ago I got from Dean some pictures from the simulation he did for Amimon. (attached the email).
Yesterday I got from Noel the simulation file (attached also)
I attached also a short presentation (which I already sent you by email 2 weeks ago) with our requirements.
Below are some question regarding the results (I use PLLat version 1.5.4). If you see that a better option to have a short webex discussion instead- please let me know
1.When I cover (with Noel simulation file) the frequency range which I need (10.82-12.62 GHz) I got design warning "VCO/MinHighCap Restricted BW". How should I overcome it? is this significant issue?
2. You choose to use is a 2nd order Loop filter . Why? can you explain shortly (if possible) the trade off to 3rd order
3. The cap C1 you choose is 2.7nF (below 3.3nF). The value gives a yellow mark. How should I consider this regarding you recommendation to use value > 3.3nF.
4. At your simulation file: when I choose "Spurs" tab and then go back to "Filter Designer" tab and then go back again to "FilterDesigner" tab- I see spurs marks on the graph which have not appear before. Is it a simulation bug ? (I add a picture with a red mark).
5. I added a simulation with the suffix"Refael". At this simulation I change C1 to be 3.3nF and C2=22nF.
Basically I do not see significant differences with your simulation but the value of C1 is 3.3nF here. What do you think?- should I use these value instead? (I can handle the loop filter small degradation at 10.82GHz to Loop=189KHz.)