I measured lock time that is much longer than 3.5 ms. I like to lower the lock time so I changed Timeout values and measured minimum and maximum lock times:
|tlock_min [ms]||tlock_max [ms]||alc||sl||vc||tl|
To me it sees that ALC Timeout of 30 is only useful for high PFD frequencies like 61MHz.
I use following equations:
alc = 30 = 30 [ADF5355 Datasheet rev.d, p.35]
sl = alc / 2,5 = 30/2,5 = 12 [ADF5355 Datasheet rev.d, p.35]
vc = ceiling(fpfd /2400000) = ceiling(1024/2040) = 1 [ADF5355 Datasheet rev.d, p.35]
tl = ceiling(fpfd * 50µs/alc) = ceiling(1024000*50µs/30) = 2 [ADF5355 Datasheet rev.d, p.35]
To me it seems that ALC is to much for a PFD frequency like 1.024 MHz.
How can I compute ALC Timeout for my application to lower lock time with reliable lock detect?
You will find attached the ADF4355 Software config file for the ADF5355 Software.