pll damping factor

Generally we set the damping facotr be be between 0.7 and 1, but sometimes larger damping factor, such as 3 or even larger are used. Can someone tell me how the damping factor infulence the PLL performance ? What 's the criteria to deciede the damping facotr?

Thanks ~

system having damping factor greater than 1 is very difficult to analyse and also less tools are available to analyse it....so we should be cautious when we are using such systems

If you have a PLL that has a wide range of divider ratios, you find that the damping factor changes as the divider N changes. For the smallest N (highest open loop gain), you set the damping to be the least that you can have, and then when N goes to its highest value, you live with the resulting overdamping. That way you at least have a stable PLL over the entire frequency range.

But there do exist PLLs with damping facotr larger thant 1...What's the benifit ?

Added after 24 minutes:

So what is the exact benifit if damping facotr large than 1?

with greater damping factor, you get less jitter peaking.

i think the PLL with high damping factor are used in demodulation , and data recovery

but PLL with low damping factor are used in freq synth.


khouly