Diode semiconductor,it is also known as crystal diode,and it is referred to as the diode (diode).The diode semiconductor is a kind of electronic device that can conduct current in one direction.A PN junction two lead terminals within the diode semiconductor,the electronic device according to the direction of the applied voltage, with conductivity of unidirectional current.
Diode's volt ampere characteristic anode:the electrode which draws out from the P area is the anode.
Cathode: the electrode is led out of the N region.
The point contact type diode, which is small in current,it is small in junction capacitance, and it is suitable for high frequency circuit and switching circuit.
Surface contact type diode, large junction area, large current, large junction capacitance,the diode semiconductor is suitable for low frequency rectifier circuit.
Planar diode, large junction area can be through a larger current, suitable for large power rectifier, the junction area is smaller,it can be used as a digital circuit in the switch tube.
Turn on voltage Uon: the critical voltage to which the diode begins to turn on is called the open voltage Uon.
Reverse current: when the reverse voltage of the diode is large enough, the reverse current is IS.
When the ambient temperature is increased, the forward characteristic curve of the diode will move to the left. As shown in figure.
The forward voltage drop of 2~2.5mV is decreased by 1 degrees C, and the temperature increases by 10 C, and the reverse current is about twice as high.
Conclusion: the diode semiconductor is sensitive to temperature.
Materials are divided into germanium, silicon or gallium gallium; according to the structure of a point contact, PN junction, pin, Schottky barrier, heterojunction; according to the principle of the tunnel, variable capacity, avalanche and step recovery, etc.. They are mainly used for detection, mixing, parametric amplification, switch, rectifier regulator, etc.. After the development of optical communication, there are light emitting, photoelectric, avalanche photoelectric, pin photoelectric, semiconductor laser diode.
1 maximum rectifier current IF: refers to the long-term operation of the diode, allowing the maximum DC current.
2 maximum reverse operating voltage UR: the normal use of the diode allows the maximum reverse voltage.
Voltage regulator diode is a surface contact type crystal diode made of silicon material. When the voltage regulator tube and the reverse voltage to a certain extent the value will be broken down.