Op-Amp Amplifier

\usepackage{circuitikz}

\begin{circuitikz}
  \draw (0,0) node[op amp] (opamp) {};
  \draw (opamp.-) -- (-1.5,0.5) to[R, l=$R_1$] (-3,0.5) to[V, v=$v_{in}$] (-3,-1) node[ground]{};
  \draw (opamp.-) -- ++(0,0.5) to[R, l=$R_2$] (opamp.out |- opamp.-) -- (opamp.out);
  \draw (opamp.+) node[ground]{};
  \draw (opamp.out) to[short, -o] (1.5,0) node[above]{$v_{out}$};
\end{circuitikz}