\documentclass[]{standalone}
\input{./tikzpreamble}

\begin{document}
\begin{circuitikz}[scale=2]
    \draw[color=black, thick]
    (0,0) node[left]{$V_{SS}=-48V$}
        to [short,o-*] (1.5,0){} % Baseline for connection to ground
    (1,0) 
        to [R, text width=1cm, l={R? 240k}, *-] (1,3)
        to [R, text width=1cm, l={R? 1k}, *-] (1,6)
        (0,6) to [short, o-] (1,6)

    (2.1,3) node[fd op amp] (fdoa) {}
    (fdoa.+) to (1,3)
    (fdoa.-) to (1.5,0)
    (fdoa.down) to (2.06,0)
    (fdoa.down)+(-.2,-.1) 
        to (1.86,2.2)
        to (.1,2.2)
        to [short, -*](.1,6)
    (fdoa.up) 
        to (2.06,6)
        to (5,6)
    (fdoa.up)+(-.2,.1)
        to +(-.2,1)
        to [short, -*] +(0,1)
    
    (4,3) node[op amp] (oa) {}
    (fdoa.out -) to (oa.-)
    (fdoa.out +) to (oa.+)

    (2.06,0) to [short,-o] (6,0) node[right]{GND}
    (5,0) node[ground]{} node[circ](4.5,0){}
    (5,0) 
        to [R, text width=1cm, l=$R20$ 1k] (5,3)
        to [R, l=$R21$, *-*] (5,6)
        to [short, -o](6,6) node[right]{$V_{DD}=3.3 V$}

    % Mosfet Transistors
    ; 
\end{circuitikz}
\end{document}