\begin{tikzpicture}
%--------start graphics code --------
%Define figure dimensions
\def\figHt{4};
\def\figWd{7};
%Grid for intial drawing.
%Comment next three lines once typesetting finished
\draw[step=0.5,very thin, black!20] (-0.5,-0.5) grid (\figWd,\figHt);
\foreach \x in {0,...,\figWd} {\node [anchor=north] at (\x,-0.5) {\x};}
\foreach \y in {0,...,\figHt} {\node [anchor=east] at (-0.5,\y) {\y};}
 
%###########################################%
%%%%%%%%%% common source amplifier %%%%%%%%%%
%###########################################%
\path (3,0) coordinate (ref_node1) {};
\path (ref_node1) ++(0,\figHt) coordinate (ref_node1T);
%Instantiation of components
\draw (ref_node1) node[nmos,anchor=source] (M1){};
\draw (ref_node1T) to [R=$R_D$] (M1.drain);
%Inter-connections 
% Numbering the components and naming the nodes
\draw (M1.base) node[right]{$M_{1}$};
\draw (M1.drain) node[circ] 
           -- ++(0.5,0) node[ocirc] node[right]{$v_{out}$};
\draw (M1.gate) node[ocirc] node[left]{$v_{in}$};
%Ground and Vdd lines
\draw (M1.source) node[ground]{}; 
%\draw (M1.source) ++(0,4) node[ocirc] 
%                   node[above] (VDD){$V_{DD}$};
\draw (ref_node1T)  node[rground,yscale=-1] (VDD){} 
                   ++(0,0.3) node[above]{$V_{DD}$};
 
%###########################################%
%%%%%%%%%% source follower %%%%%%%%%%
%###########################################%
\path (6,0) coordinate (ref_node2) {};
\path (ref_node2) ++(0,\figHt) coordinate (ref_node2T);
%Instantiation of components
\draw (ref_node2T) node[nmos, anchor=drain] (M2){};
\draw (M2.source) to [R=$R_S$] (ref_node2T);
%Inter-connections 
% Numbering the components and naming the nodes
\draw (M2.base) node[right]{$M_2$};
\draw (M2.gate) node[ocirc] node[left]{$v_{in}$};
\draw (M2.source) node[circ] 
           -- ++(0.5,0) node[ocirc] node[right]{$v_{out}$};
%Ground and Vdd lines
\draw (ref_node2) node[ground]{}; 
\draw (ref_node2T)  node[rground,yscale=-1] (VDD){}  
                   ++(0,0.3) node[above]{$V_{DD}$};
 
%--------end graphics code ----------
\end{tikzpicture}