Semiconductor diode by materials with germanium, silicon or gallium arsenide; according to the structure with point contact, PN, pin, Schottky barrier, heterojunction; according to principle minute tunnel, varactor, avalanche and step recovery. Mainly used for detection, mixing, parametric amplifier, switch, voltage regulator, rectifier and other. The development of optical communication, optical, appearing after light, avalanche, pin optoelectronic, semiconductor laser diode.
Semiconductor diode
The volt-ampere characteristic of diode anode: from P extraction electrode as anode.
Cathode: from N extraction electrode as cathode.
Point contact diode, the current through the junction capacitance of small, small, suitable for high frequency circuit and a switch circuit.
Planar diode, node when the area is larger by a larger current, suitable for large power rectifier, junction area is small, can be used as a digital circuit in the switch tube.
Turn-on voltage of Uon: LED began conducting critical voltage called the turn-on voltage of Uon.
In the environmental temperature rises, the diode forward curve shifts to the left, the reverse characteristic curves. As shown in figure.
For every increase of 1 degrees C temperature, forward voltage drop decreases by 2 ~ 2.5mV; temperature increased 10 degrees C, the reverse current of approximately doubled.
Conclusion: diode is very sensitive to temperature.
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