combined desc of filter

Final.tex

@@ -169,7 +169,30 @@ $V_{CC} = \pm \SI{15}{V}$.
   \includegraphics[width=0.4\textwidth]{lm741_oclsg}
 \end{figure}
 
-\section{Ease of Use}
+\section{A Combined Description of the Filter}
+
+Using the more complete model of the op-amp makes analysis more
+complex. The following observations simplify the task:
+\begin{itemize}
+\item $v_p$ remains at ground potential, so the dependent voltage
+  source has voltage $A(-v_n)$
+\item $R_i \to \infty$ is, in effect, an open circuit, so the $R_i$
+  branch need not be considered
+\item $R_o = 0$ is a wire, and $R_o$ can be ignored.
+\end{itemize}
+
+The simplified circuit can be depicted as such:
+
+\begin{figure}[h]
+  \caption{A simplification of the combined model}
+  \begin{circuitikz}[american voltages]
+   \draw (0,0) node[left=0cm]{$v_{in}$} to [short, o-] [R, l_=$R_1$, i=$i$] (1.5,0);
+   \draw (1.5,0) to [C, l_=$\frac{1}{j\omega C_1}$] (2.75,0);
+   \draw (2.75,0) node [above=0.1cm]{$v_n$} to [short, o-] [R, l_=$R_2$] (5,0);
+   \draw (5,0) node [above=0.1cm]{$v_{out}$} to [short, o-] [american controlled voltage source, label=$A(-v_n)$] (7,0);
+   \draw (7,0) node[ground]{};
+\end{circuitikz}
+\end{figure}
 
 \subsection{Maintaining the Integrity of the Specifications}