\begin{circuit}1

%Capacitor
\cc\nl \C1 {$v_C(t)$} d
\- 2 d

\atpin C1t
\- 2 u

% Corriente
\frompin C1b \shift -1.5 -1
\nl \whatI1 {$i_C(t)$} d u
\vtopin C1t
\- 1 u 

% Tension

\atpin C1t \shift 0.5 0
\put{$+$}

\atpin C1b \shift 0.5 -0.5
\put{$-$}


\end{circuit}