What is the purpose of using 2nd order loop filter for DLL?

[shady205]

why can't we use a 2nd order DLL and wht is the modification by using the second order DLL..

even though we use DLL to change the phase differnce then wht is the purpose of using the 2nd order loop filter.

 

[jeepx5]

question about DLL

Cuz the 2nd order DLL might be unstable.
And the loop filter is used to minimize the ripple of the control voltage to reduce the jitter