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Types of semiconductor diodes

Lecture



A semiconductor device with one electrical junction, whose job it is to convert one electrical value to another, is called a diode. The design of this product provides two outputs for installation.

  Types of semiconductor diodes

Semiconductor diodes

On circuit diagrams, semiconductor diodes are depicted as a triangle and a segment located on one of its vertices and located parallel to the opposite side.

  •   Types of semiconductor diodes rectifier, pulsed and universal
  •   Types of semiconductor diodes zener diodes and stabistory
  •   Types of semiconductor diodes tunnel
  •   Types of semiconductor diodes converts
  •   Types of semiconductor diodes varicaps

Depending on the design of the diode, its designation may include additional symbols. In any case, the apex of the triangle, adjacent to the center line of the diode, indicates the direction of current flow.

  Types of semiconductor diodes

In the part of the designation where the triangle is located, there is a p region, which is also called the anode or emitter, and from the side where the segment is adjacent to the triangle, there is an n region, which is respectively called the cathode, or base.

Semiconductor diodes, the purpose of which is to convert AC to DC, are called rectifier. AC rectification using a semiconductor diode is based on its one-sided electrical conductivity, which is that the diode creates a very small resistance to the current flowing in the forward direction, and a sufficiently large resistance to reverse current.

In order to rectify the current of high power without fear of thermal breakdown, the design of the diodes should provide a significant area of p - n - junction. In this connection, with what in rectifying semiconductor diodes involve special p - n -transitions corresponding to the latest science and technology.

The technology of creating the p n junction is obtained by introducing a p -or n -type impurity into the semiconductor, which creates an area with the opposite conductivity in it. Impurities can be added by fusion or diffusion.

Diodes produced by the fusion method are called “ alloy ”, and those produced by the diffusion method are called “ diffusion ”.

  Types of semiconductor diodes

Simplest rectifier

During the positive half-period of the input voltage U 1 diode V working in the forward direction, its resistance is small and at the load R H voltage U 2 almost equal to the incoming voltage.

  Types of semiconductor diodes

Graph of voltage at the input and output of the simplest half-wave rectifier

With a negative half-period of this input voltage, the diode is turned in the opposite direction, where its resistance is formed much more than the resistance on the load, and almost all the incoming voltage drops on the diode, and the voltage on the load approaches zero. In such a scheme, only one half-cycle of the incoming voltage is used to obtain the rectified voltage, so this type of rectifier is called half-wave.

Semiconductor diodes that are used to stabilize the DC voltage across the load are called zener diodes. In the Zener diodes involved a plot of the reverse portion of the current-voltage characteristics in the field of electrical breakdown.

  Types of semiconductor diodes

The scheme of the simplest voltage stabilizer

In this case, when the current passing through the Zener diode changes from I ст. мин. I ст. мин. to I ст. макс. I ст. макс. the voltage on it is almost unchanged. If the load R H connected in parallel to the zener diode, the voltage level on it will also remain unchanged within the specified limits of change in the current passing through the zener diode.

  Types of semiconductor diodes

Zener diode graph

Such diodes stabilize the voltage level from about 3,5 В and above. Stabilistors are used to stabilize the DC voltage to 1 volt. For the stabistors, the direct part of the current-voltage characteristic works not the reverse. Therefore, they are not connected in reverse, as they do with zener diodes, but in the forward direction. Electronic components, such as stabilizers and zener diodes, are usually made of silicon.

  Types of semiconductor diodes

Voltage-current characteristic of the Stabistor

Planar diodes have high capacitive characteristics. With increasing frequency, the capacitance decreases, which leads to an increase in its reverse current. At high frequencies, due to the fact that there is a capacitance in the diode, the magnitude of its reverse current can reach the value of the forward current, and this diode, thus, will lose its main property of one-sided electrical conductivity. To maintain their functional qualities, it is necessary to reduce the capacitance of the diode. This is achieved with the help of various technological and constructive methods aimed at reducing the area of ​​the p - n junction.

In the diodes used in circuits operating with high-frequency current, products with point and micro-alloy p - n junctions are used. The desired point p n junction is obtained at the point of contact of the pointed end of a special metal needle with a semiconductor. In this case, the method of electroforming is used, which consists in the fact that through the junction of the wire and the crystal semiconductors flow pulses of electric current, forming in the place of their contact p - n junction. Micro-alloys are called such diodes, in which a p - n junction is created by electroforming a contact between a semiconductor plate and a metal object with a flat end.

A semiconductor diode is a semiconductor device with one electrical junction and two leads (electrodes). Unlike other types of diodes, the principle of operation of a semiconductor diode is based on the phenomenon of pn junction.

Planar pn junctions for semiconductor diodes are obtained by the method of fusion, diffusion, and epitaxy. [one]

Content

  • 1 Main characteristics and parameters of diodes
  • 2 diode classification
    • 2.1 Types of diodes to destination
    • 2.2 Types of diodes in the frequency range
    • 2.3 Types of diodes by size of transition
    • 2.4 Types of diodes by design
    • 2.5 Other types
  • 3 Notes
  • 4 Literature
  • 5 References

Main characteristics and parameters of diodes

  Types of semiconductor diodes

DG-TS25 diode. 1959

  • Volt-ampere characteristics
  • Maximum allowed constant reverse voltage
  • Maximum allowed impulse reverse voltage
  • Maximum allowed constant forward current
  • Maximum allowed impulse forward current
  • Rated direct current
  • Direct direct voltage on the diode at rated current (the so-called "voltage drop")
  • DC reverse current, indicated at maximum allowed reverse voltage
  • Working frequency range
  • Capacity
  • Breakdown voltage (for protective diodes and zener diodes)
  • Thermal resistance of the case with different mounting options
  • Maximum allowable power dissipation

Diode classification

Types of diodes to destination

  • Rectifier diodes are designed to convert AC to DC.
  • Pulsed diodes have a short duration of transients, designed for use in pulsed modes of operation.
  • Detector diodes are designed to detect the signal
  • Mixing diodes are designed to convert high-frequency signals into an intermediate frequency signal.
  • Switching diodes are designed for use in devices controlling the level of microwave power.
  • Parametric
  • Restrictive diodes are designed to protect the radio and household equipment from increasing mains voltage.
  • Multiplying
  • Tuning
  • Generator set

Types of diodes in the frequency range

  • Low frequency
  • High frequency
  • Microwave

Types of diodes by transition size

  • Flat
  • Dotted

Types of diodes by design

  • Schottky Diodes
  • Microwave diodes
  • Zener diodes
  • Stabistors
  • Varicaps
  • LEDs
  • Photodiodes
  • Pin diode
  • Avalanche diode
  • Avalanche flight diode
  • Diode Gunn
  • Tunnel diodes
  • Reversed Diodes

Other types

  • Selenium rectifier (valve) [2]
  • Copper-soured rectifier (valve) [2]

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Electronics, Microelectronics, Element Base

Terms: Electronics, Microelectronics, Element Base