PLL loop filter selection

bandpass

As we know, the number 1 LPF in schematic is the well known circuit.
4 z9 w0 C3 r" C6 i
# Q9 K% v$ [/ Y! v) y/ A3 r9 Q, w9 W   But some application is like the number 2 LPF in schematic. Any commetions about it ?

5 Q: p& Z  c/ w# O: s& [' l& H; ~   Any discussion is appreciated.

circuitman5566

thank you so much! thank you so much! thank you so much!