\begin{circuit}2

% Amplificador
\ov1 {} - {$v^-$} {$v^+$} {}

% Primer resistor
%
\atpin OV1-
\- 2 d
\.1
\cc\nl \spring1 {$R_1$} d
\- 1 d \P1

% Corriente
\frompin spring1b \shift -1.2 0
\nl \whatI1 {$i_1$} d u
\vtopin spring1t

% Cables al segundo resistor
\atpin .1
\- 5 r

%
% Segundo resistor
%
\cc\nl \spring2 {$R_2$} r
\htopin ov1O
\vtopin ov1O
\.2

% Corriente
\frompin spring2l \shift 0 -1.2
\nl \whatI1 {$i_2$} d r
\htopin spring2r



%Conectores
\atpin ov1+
\connection1 {$v_i$} c l

\atpin .2
\connection1 {$v_o$} c r


% Tierra
\atpin P1
\gnd1



\end{circuit}