What is a diode in the article content? What is Diode Structure? How Does It Work? And What Are Diode Types? You will find answers to questions such as.
The word diode was produced by combining "di" meaning two and "ode" meaning road in Greek language. Diode is an electronic element. The diode used on printed circuit boards flows electric current in only one direction.
What is the diode structure? How Does It Work?
Germanium and silicon Diodes produced from semiconductor materials such as diodes have 2 ends, one called anode and the other called cathode. The diode, which is one of the basic elements of the electronics industry, consists of 2 regions as P-type and N-type. There are positively charged cavities in the P-type part and negative electrons in the N-type part. Thus, current flows only when the correct polarisation is made.
For current to flow through the diode forward polarisation must be done. The correct polarity is obtained by applying positive voltage to the anode end of the diode and negative voltage to the cathode end. When negative voltage is applied to the anode leg of the diode reverse polarisation realised and no current flows from the circuit. This feature is used on electronic circuits for many purposes such as half wave rectifier, full wave rectifier, voltage protection, bypass.
What are Diode Types?
What is a diode? Let's talk about its types after the question. There are many types of diodes used in technology such as LED, laser diode, photo diode, germanium and silicon (normal) diode, zener diode, tunnel diode, varactor (varicap) diode, shottky diode, bridge diode, PIN diode, gunn diode ....
LED: Rod LED models located on LED (Light Emitting Diode) is also a type of diode. They emit light in different colours in the correct polarity.
Laser Diode It produces light just like LED. But it produces a more powerful and flat light. Its power is increased by semiconductor doping.
Photo Diode It conducts with light. As the light falling on it increases, the leakage current in the opposite direction increases.
Normal (Germanium and Silicon) Diode: Silicon diodes with very low reverse leakage current have higher forward voltage threshold voltage than germanium diodes. While germanium has a threshold voltage of 0.2 - 0.3 V, this value is in the range of 0.6 - 1.7 V in silicon diodes.
Zener Diode It works like a normal diode in correct polarity. In reverse polarity, it does not pass current until a certain voltage value. However, after reaching the breakdown voltage, current flows through it. This value is certain. It is frequently used in protection circuits. It also keeps the voltage applied to its ends constant.
Tunnel Diode They are highly doped. It creates negative resistance in forward polarisation. Therefore, they switch very fast. It works according to the tunnel effect principle. So when the voltage increases, the current decreases. It works like a standard P-N diode in reverse polarity. It is preferred in radio, oscillator or switching circuits.
Varactor Diode Its other name is varicap diode. It works like a standard P-N diode but creates a certain capacitance. It is used in communication circuits, remote control circuits or oscillators.
Schottky Diode In correct polarisation, it flows current immediately even at a very low voltage in the range of 0.15 - 0.45 V. It makes fast switching. It is generally used in power circuits.
Bridge Diode It converts the AC voltage applied to its input into DC direct current. It consists of 4 normal PN diodes. They act as rectifiers in rectifier circuits.
PIN Diode Variable resistance. Its structure is PIN-shaped. Between the P semiconductor region and the N semiconductor region, there is also the I region with large resistance. The resistance of the I region decreases in direct polarisation and increases in reverse polarisation under high frequency. It is used in modulator, phase shifter or microwave applications.
Gunn Diode In correct polarisation, at a certain voltage value, the current flows only for a certain period of time and then stops. In this way it creates an oscillation.
