LMX2485 in PLLatinum SIM with external VCO.

john greene

Other Parts Discussed in Thread: LMX2485E, LMX2485

I would like to enter in the VCO phase noise information of the VCO I want to use with the LMX2485e in PLLatinum SIM software. What is the file format?

over 7 years ago

0 Julian Di Matteo over 7 years ago

TI__Expert 4085 points

Hi John,

We Received your question. Thank you for your interest in our products. I forwarded this post to the applications engineer most familiar with this device.

Regards,
Julian

0 Dean Banerjee over 7 years ago

TI__Mastermind 27581 points

If you check the ? for help it will tell you.

The format is:

Offset1, Noise1 + <CarriageReturn>

Offset2, Noise2 + <CarriageReturn>

0 john greene over 7 years ago in reply to Dean Banerjee

Intellectual 435 points

For some reason the little ? Don't work for me.

Can you tell me why the online workbench simulator for the lmx2485 gives very different results when calculating loop filters than PLLatinum Sim does? I took the values work bench gave me for a 10kHz filter PLLatinum Sim said it was 3.5kHz?

Why doesn't PLLatinum SIM allow me to just enter 3 points for VCO phase noise like it does for the reference oscillator? The 'Metrics' values are grayed out and can't be changed like they can for the reference.

0 Nigel Wilson over 7 years ago in reply to john greene

Prodigy 20 points

The file format doesn't work for me either, can somebody post an example file that works?

Thanks!

0 Stephen Heald over 7 years ago in reply to Nigel Wilson

Prodigy 10 points

I had a play with the text file format, frequency in Hz and dBc/Hz separated by a tab appears to be accepted.
ie,
10000 -89.8
1000000 -136.9
38000000 -155.5
But the outcome on the graphs, doesn't make sense?
A few other bugs noted, with fields not being updated when you load from a saved file.
The TI PLLatinum Sim looks really useful, and I hope these various bugs will be addressed.

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LMX2485 in PLLatinum SIM with external VCO.