what's the meaning of the fourth-order type2 charge pump pll

[jerryhuang]

thanks

 

[eng_Semi]

Re: what's the meaning of the fourth-order type2 charge pump

Fourth order means that the loop filter is of 3rd order
TypeII means that the open loop response of the PLL contain two poles at s=0

 

[jerryhuang]

thanks,does the fourth-order pll have good noise performance than third-order pll?And I still don't know the meaning of typeII or type I ?for a cppl,how can I modle the open-loop response ,does the type also depend on the loop filter transfer function?

 

[dikshits]

Re: what's the meaning of the fourth-order type2 charge pump

This pdf by Motorola on the PLL design Fundamentals will help you in understanding the difference between the type and order of PLL.