The diode can be considered as a particular case of non-linear resistor. Although the device category of nonlinear circuits is very wide and requires generally methods of investigation of considerable complexity, the most important diode circuits in electrical and electronic applications do not always require excessive conceptual complications for their understanding. There are different categories of diodes, among these the most significant are:

  • rectifiers diodes;
  • zener diodes;
  • diodes LED;
  • photodiodes;
  • varactor diodes;
  • Schottky diodes.