In the world of electronics, of course, you are familiar with a component called a diode. A diode is an electronic component composed of a combination of two semiconductors, each of which is added with a different material and additional conductor material to conduct electricity.
It can be said that the main structure of the diode is a two-pole (anode and cathode) electrode made of conductors, each connected by a p-type (positive) silicon semiconductor and an n-type (negative) silicon semiconductor.
The anode pole is the electrode connected to the positive type of silicon with fewer electrons, while the cathode is the electrode connected to the negative type of silicon with more electrons.
Semiconductor materials commonly used in diodes made from silicon or germanium. While p-type semiconductors are made by adding materials that have less than 4 valence electrons (boron). For n-type semiconductors, it is made by adding a material that has more than 4 electro valence (phosphorus).
Although it has a simple structure, it turns out that the diode has a very complex function and is generally used for AC wave rectifiers to become DC, because its function is to block the incoming voltage from the cathode pole.
1. AC Relay Source
Diodes can be used as induction protection in relay circuits. Generally, relays contain a large number of turns which can turn into a magnetic field when electricity flows.
In addition, the relay winding can also be stored electric current. However, this condition is considered dangerous because it can cause damage.
Therefore, precautions are made on the relay so that it is safe. There is a transistor controlling the relay which is also safer if there is a diode in the winding.
2. DC Reverse Input Protector
The existence of a diode is very important specially to protect the DC input voltage in many circuits. As is known, human error is the cause of damage to electrical equipment.
The presence of error diodes due to human actions can be reduced. Especially if you do the installation to the power supply and connected to the system circuit.
3. Overvoltage Protection
In high-voltage electronic devices must be installed diodes. As found in the H diode bridge circuit contained in the motor driver where there is a voltage spike in it.
The presence of a mains voltage diode can be trimmed and protect sensitive components. Zener diode is a diode that is often used for high-voltage electronic devices.
4. Other Functions
In addition to those described above, here are some other functions of the diode:
- As a heat sensor on the amplifier.
- Can add DC particles to the AC signal.
- As a fuse or switch and safety electrode circuit.
- As a voltage multiplier.
- As a rectifier.
Functions by Diode Type
Not only that, the function of diodes can also be distinguished by type. Based on the type, the diode functions as:
| Diode Type | Function |
| PN Junction Diode | Diodes are composed of PN and are widely used in the market. Functions as a rectifier of electric current. |
| Light Emitting Diode (LED) | Is commonly used as a lighting device and as a substitute for fluorescent lamps. |
| Laser Diodes | Diodes that can produce light with a coherent type of light. Applied to CD and DVD readers and laser pointers. |
| Photodiode | A diode that can generate electrical energy when the PN junction is illuminated. Usually the photodiode is operated in a reverse-biased condition so that even small currents can be detected immediately. The function of the photodiode is to detect light or a photodetector. |
| BARITT | Diode Function to produce microwave signals with low noise levels. |
| Backward Diode | Has the same character as the tunnel except that there is a lower doped side when compared to the opposite side. Its function can flow the same current with reverse and forward conditions. |
| Gunn Diodes | Diodes that do not have a PN junction and consist of only two electrodes. The function of the diode is to produce a microwave signal. |
| Tunnel Diodes | Diodes are used as a component of an oscillator, amplifier, or signal mixer, mainly because of the speed at which it reacts to changes in voltage. |
| Step Recovery Diode | Diodes that can reduce switching time because there is less charge in the junction area. |
| PIN Diodes | These diodes have an intrinsic semiconductor area that sits between the P and N junctions. So that the function of the PIN diode is to widen the depletion area which limits the movement of electrons during signal-related applications. |
| Schottky Diode | The function of this diode is to create a low activation voltage and a fairly short recovery time. Used in high-frequency electronic circuits. |
| Varactor Diodes | Are in normal reverse mode with a barrier layer that varies according to the applied voltage. This makes the diode look like a capacitor. |
| Zener Diodes | There are special characteristics that can increase the breakdown effect when reverse biased. The function of the diode is to produce a constant and common voltage when used as a reference voltage generator in electronic circuits. |
Those are some of the functions of the diode in an electronic circuit.