JFET in common source wiring:
AC equivalent:
Feel free to edit and compile the code:
\documentclass[border=50pt, tikz]{standalone} % Circuits \usepackage[european,s traightvoltages, RPvoltages, americanresistor, americaninductors]{circuitikz} \tikzset{every picture/.style={line width=0.2mm}} % Tikz Library \usetikzlibrary{calc} % Bipoles Specifications \ctikzset{bipoles/thickness=1.2, label distance=1mm, voltage shift = 1} \def\nu{10} \definecolor{myblue}{HTML}{ABDCEC} \begin{document} \begin{tikzpicture} \begin{circuitikz} \ctikzset{voltage/american plus/.initial={}, voltage/american minus/.initial={}} % %Grid % \draw[thin, dotted] (0,0) grid (\nu,\nu); % \foreach \i in {1,...,\nu} % { % \node at (\i,-2ex) {\i}; % } % \foreach \i in {1,...,\nu} % { % \node at (-2ex,\i) {\i}; % } % \node at (-2ex,-2ex) {0}; %Coordinates \node[njfet] (Q) at (5,3.5) {}; % Circuit \draw (Q.S) node[shift={(-0.3,0)}] {$S$} to[R, l^=$R_3$, *-*] ++(0,-2.5) node[ground] (GR) {} (Q.D) node[shift={(-0.3,0)}] {$D$} to[R, l^=$R_2$, *-] ++(0,2.8) node[vcc] {$+V_{DD}$} (Q.D) to[C, l^=$C_2$] ++(4,0) -- ++(0,-1.35) node (D') {} to[open, v=$v_o$, o-o, american] ++(0,-1.3) -- (GR -| D') -- (GR) (Q.G) node[shift={(0,0.4)}] {$G$} -- ++(-1,0) node[inner sep=0, outer sep=-1] (G') {} to[R, l_=$R_1$] (GR -| G') (G') to[C, l_=$C_1$] ++(-3,0) node (G'') {}; \draw (GR) -- (GR -| G''); \draw[dashed] (Q.S) -- ++(2,0) to[curved capacitor, l^=$C_3$, -*] ++(0,-2.5) (G'') to[sV, l_=$v_{in}$, *-*] (G'' |- GR); \end{circuitikz} \end{tikzpicture} \begin{tikzpicture} \begin{circuitikz} \ctikzset{voltage/american plus/.initial={}, voltage/american minus/.initial={}} % % Grid % \draw[thin, dotted] (0,0) grid (\nu,\nu); % \foreach \i in {1,...,\nu} % { % \node at (\i,-2ex) {\i}; % } % \foreach \i in {1,...,\nu} % { % \node at (-2ex,\i) {\i}; % } % \node at (-2ex,-2ex) {0}; % Coordinates \coordinate (G) at (0,5); \coordinate (S) at (0,0); % Circuit \draw % Left Part (G) node[shift={(-0.4,0)}] {$G$} to [open, v_=$v_{gs}$, *-*] (S) node[shift={(-0.4, 0)}] {$S$} (G) -- ++(4,0) coordinate (G) to [open, v=$r_{gs}\to\infty$, o-o, american] ++(0,-2.5) coordinate (ML) (S) -- ++(2,0) coordinate (SL) to [R, l^=$R_1$] (SL |- G) coordinate (G') (SL) -- ++(2,0) % Right Part (ML) -- ++ (3,0) coordinate (MR) to [american current source, l^=$g_mv_{gs}$, invert] ++(0,2.5) -- ++(6,0) coordinate (D) node[shift={(0.4, 0)}] {$D$} (MR) -- ++(2,0) coordinate (MR') to [R, l^=$r_{ds}$] (MR' |- D) coordinate (D'') ($(ML)!0.5!(MR')$) to [R, l_=$R_3$] ++(0,-2.5) coordinate (SM) -- (S) (D'') -- ++(2,0) coordinate (D') to [R, l^=$R_2$] (D' |- S) coordinate (SR') (SR') -- (SR' -| D) coordinate (SR) (SR') -- (SM) (D) node[shift={(0.4,0)}] {$D$} to [open, v^=$v_{ds}$, *-*] (SR) node[shift={(0.4, 0)}] {$S$} (D) to [short, i=$i_{D}$] (D'); % Rectangle \draw[draw=none, fill=black, fill opacity=0.35] ($(ML) - (1,0.4)$) rectangle ($(D'')!0.5!(D') + (0,0.4)$); \end{circuitikz} \end{tikzpicture} \end{document}