how to caculate the filter's parameters

[Amy Wu]

Hi All,
i want to design a PLL,now i have met with some problems.i'd like to use an active filter,but don't know how to caculate the filter's parameters.can u help me?thanks a lot!

 

[eng_Semi]

check National application note AN1001, you will find in it the equations by which you can design the loop filter.

 

[sriramachandra]

please refer to the following book by national semi employee banerjee i believe.
It has good explanation


"PLL Performance, Simulation & design"

thanks

 

[Amy Wu]

thank u for ur help.i have read the book u have recommended.i want to use a 3 order active filter with an opamp.the PLL BW is 100KHz,but i found it very hard to design a loop filter on chip.can u give me some more advices?