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 ?4 H' V. o" |8 W+ |& u$ F+ c
5 Q: p& Z c/ w# O: s& [' l& H; ~ Any discussion is appreciated.