Settling time specification

[The Commando]

Hi,
I'm designing an RF frequency synthesizer (sigma-delta fractional-N PLL) for an LTE sys. , in system level design, I need the synthesizer specifications , how can I determine the Settling Time spec ?? ... I can't find any condition in LTE standard on how fast can the system changes the channel ... How can I determine this spec ????????????????????

 

[jiripolivka]

The settling time in frequency synthesizers is specified as the time delay between the command end and the frequency stabilized at the commanded value.
Some synthesizers typically settle within a fraction of a second, special "fast-settling" types, within < one millisecond.

 

[RFDave]

Start with the channel handoff timing requirements and go from there.

Dave

 

[tony_lth]

You can use ADISimPLL to simulate and get comparable setting time to lock a VCO.