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

\begin{document}
\begin{circuitikz}[scale=2]
    \draw[color=black, thick]
    (1,0) 
    to [R, text width=1cm, l={R 500$\mu$},f>^=I$_{IN}$,  *-] (1,6)
    to [short, -o](0,6) node[left] {V$_{IN} = -48V$}

    (1,5.1) node[draw=black, fill=white, regular polygon, regular polygon sides=4] {PowerIt}

    (0,0) node[left]{GND$_{V_{IN}}$} to [short, o-] (1,0)

    (2.1,3) node[fd op amp] (fdoa) {}
    (fdoa.+) to [short,-*] (1,2)
    (fdoa.-) to [short,-*] (1,4)
    (fdoa.down) to (2.06,0)
    (fdoa.down)+(-.2,-.1) 
        to (1.86,0)
        to [short, -*](1,0)
    (fdoa.up) 
        to (2.06,6)
        to [short,-o](6,6) node[right] {$V_{SS} = 3.3V$}
    (fdoa.up)+(-.2,.1)
        to (1.86,6)
        to [short, -*] (2.06,6)
    
    (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){}

    (oa.out) to [short,-] (5.5,3) node[right,draw=black] {MONITOR\_48I}
    ; 
\end{circuitikz}
\end{document}