\node[nfet](mos) at (0,0) {};


\draw (mos.source) to [short,-]  ++ (0,-0.1)   coordinate(vsplus)
                   to [ V
                      , i_=$i_{\mathrm{S}}(t)$
                      ]          ++ (0,-2.5)   coordinate(gnd);

\node[ground] () at (gnd) {};

\draw (vsplus) to [short,*-o]  ++ (1,0) coordinate(vsplus);

\draw (mos.bulk) to [short,-]   (vsplus|-mos.bulk)
                 to [short,-o]  ++ (2,0)        coordinate (vbplus)
                 to [ short
                    , i<=$i_{\mathrm{B}}(t)$
                    ]           ++ (1,0)        coordinate (x)
                 to [V]         (x|-gnd)
                 to [short,-o]  (gnd-|vbplus)   coordinate (vbminus)
                 to [short,-o]  (gnd-|vsplus)   coordinate (vsminus)
                 to [short,-*]  (gnd);

\draw (mos.drain) to [short,-]   ++ (0,1)       coordinate (y)
                  to [short,-]      (x|-y)
                  to [short,-o]  ++ (1.4,0)     coordinate (vdplus)
                  to [ short
                     , i<=$i_{\mathrm{D}}(t)$
                     ]           ++ (1,0)       coordinate (z)
                  to [V]         (z|-gnd)
                  to [short,-o]  (vdplus|-gnd)  coordinate (vdminus)
                  to [short,-*]  (x|-gnd);

\draw (mos.gate) to [short,-o]   ++ (-1,0)      coordinate (vgplus)
                 to [ short
                    , i_<=$i_{\mathrm{G}}(t)$
                    ]            ++ (-1,0)      coordinate (a)
                 to [V]          (a|-gnd)
                 to [short,-o]   (vgplus|-gnd)  coordinate (vgminus)
                 to [short]      (gnd);

\tikzstyle{voltarrow}=[ -{Latex[round,scale=0.9]}
                      , semithick
                      , shorten <=3pt
                      , shorten >=3pt
                      ]

\path [voltarrow](vbplus) 
  edge[] node [midway,left,inner sep=1pt] {$v_{\mathrm{B}}(t)$} (vbminus);
\path [voltarrow](vsplus) 
  edge[] node [midway,right,inner sep=1pt] {$v_{\mathrm{S}}(t)$} (vsminus);
\path [voltarrow](vdplus) 
  edge[] node [midway,left,inner sep=1pt] {$v_{\mathrm{D}}(t)$} (vdminus);    
\path [voltarrow](vgplus) 
  edge[] node [midway,right,inner sep=1pt] {$v_{\mathrm{G}}(t)$} (vgminus);   

\tikzstyle{termstyle}=[font=\scriptsize\ttfamily,inner sep=1pt]

\node[anchor=south,termstyle] () at (mos.gate) {G};
\node[anchor=west ,termstyle] () at ($(mos.drain)!0.4!(mos.bulk)$) {D};
\node[anchor=south,termstyle] () at ($(mos.bulk)+(0.4,0)$) {B};
\node[anchor=west ,termstyle] () at ($(mos.source)!0.4!(mos.bulk)$) {S};