Digital electronics

• transistor
  • A transistor is a semiconductor device that can amplify or switch current
    • BJT (bipolar junction transistor)
      • The base is the control terminal
      • The collector is the high-voltage terminal
      • The emitter is the low-voltage terminal
      • Type of BJT:
        • NPN (negative-positive-negative)
        • PNP (positive-negative-positive)
    • FET (field-effect transistor)

Figure: An NPN transistor as a switch

todo

\usepackage{color,graphicx,circuitikz}
\begin{document}
\begin{circuitikz}[american, scale=0.7, every node/.style={transform shape}]
\draw (0,0) node[npn](npn){};
\draw (npn.B) to[R, -o] ++(-2,0) node[left] {$V_{\mathrm{in}}$};
\draw (npn.C) to[short, -o] ++(0,0) node[above] {$V_{\mathrm{cc}}$};
\draw (npn.E) to[R, -] ++(0,-2) node[ground] {};
\draw (npn.E) to[short, -o] ++(0.5,0) node[right] {$V_{\mathrm{out}}$};
\end{circuitikz}	
\end{document}