\node[op amp, yscale=-1,scale=0.8] (op) at (0,0) {}; \draw (op.out) to [R,l=$R_{\mathrm{3}}$,*-*] ++ (0,-1.5) coordinate (fb) to [R,l=$R_{\mathrm{4}}$, - ] ++ (0,-1.5) coordinate (gnd) node[sground,scale=0.7] {}; \draw (fb) -- (fb-|op.-) -- (op.-); \draw (op.+) to [short, -] ++ (-1,0) coordinate (y) to [C,l_=$C_{\mathrm{2}}$] (y|-gnd) node[sground,scale=0.7] {}; \draw (y) to [R,l_=$R_{\mathrm{2}}$,*-*] ++ (-2,0) coordinate (x); \draw (x) to [R,l_=$R_{\mathrm{1}}$,*-o] ++ (-2,0) coordinate (in) node[anchor=east] {I}; \draw (x) to [short, -] ++ (0,1) coordinate (im) to [C,l=$C_{\mathrm{1}}$] (im-|op.out) to [short,- ] (op.out) to [short,-o] ++ (0.5,0) node[anchor=west] {O}; \node[anchor=north] at (x) {X}; \node[anchor=south] at (y) {Y};