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What Is The Saturation Current of A Diode?

time 2022-11-24

Publisher: hqt


Diode Concept:

The diode is a two-terminal electronic component that conducts electric current in only one direction. The name is a contrived acronym for DIscontinuous Conduction since the current flows in this device are on and off. It was invented by Lee de Forest in 1904.

The symbol for a diode is often shown as an arrow pointing from the cathode (+) to the anode (-) side of the device, with a line representing an electrical insulator between them. This is called an “electrical schematic symbol” and it represents the physical structure of the diode as well as its function.

A semiconductor diode essentially consists of two layers of P-type and N-type material, with the P-type layer sandwiched between these two layers. When voltage is applied across such a structure, electrons will flow from P to N, but not vice versa because of their different conductivities. This phenomenon is known as “rectification”.

A diode is a one-way electronic device that allows current to flow in one direction only. Here are some types of diodes:

1. Zener diode:

A Zener diode like Linear Voltage Regulators L7905CV is a special type of diode that acts as a voltage regulator. In other words, when the voltage across the Zener diode increases beyond a specified level, the Zener diode starts conducting current.

2. Light-Emitting Diode (LED):

An LED like EASYIEE Standard LEDs LTL-4231N is a semiconductor device that emits light when an electric current passes through it. The color of the light emitted depends on the material used to make the LED.

Introduction Of Saturation Current:

Saturation current is the maximum electric current that can flow through a conductor when it is exposed to an electric field. It is due to ions and free electrons in the conductor being forced into the metal, where they become trapped by their mutual electrostatic attraction and cannot easily return to their original positions.

In other words, it is the electric current that causes all of the conductors’ free electrons to have their individual orbits “flattened” into a single plane, with no net movement of charge carriers within that plane.

The saturation current is one of several important characteristics used to evaluate the material properties of materials used in manufacturing electrical devices such as transformers and semiconductor diodes. The saturation current allows engineers to predict what voltage will cause an electrical device’s insulation to fail due to overheating or arcing between contact points.

Saturation current is the maximum current that a diode can conduct before it starts to operate in the saturation region. This occurs when the reverse voltage applied to a diode becomes so large that the depletion layer cannot completely block the flow of electrons. The types of saturation current include:

Avalanche Current:

The avalanche breakdown voltage is approximately 5-10 times greater than the breakdown voltage of an ordinary diode. In other words, when an avalanche breakdown occurs, a much higher current will flow through the device than in ordinary breakdown conditions.

Forward Breakdown Voltage:

The forward breakdown voltage is defined as the minimum voltage across an active semiconductor junction which causes sufficient carriers to be injected into or removed from the depletion region so that a significant increase in current will occur.

Ionizing Potential:

The ionizing potential is defined as the minimum voltage required to create an electron-hole pair across a vacuum interface between two electrodes having no applied bias and in thermal equilibrium at room temperature.

What’s The Saturation Current of A Diode?

The saturation current of a diode is the maximum current that can be safely passed through it. The saturation current of a diode is determined by the type of semiconductor used in manufacturing the diode, its physical dimensions, and the voltage applied across it. The saturation current is directly proportional to the material used in the diode and its geometry.

In a diode, the current that flows is due to the presence of an electric field. The electric field is produced by the voltage difference between the electrodes. The voltage difference is called the applied voltage.

The saturation current is defined as the maximum current that can be allowed to flow through a diode without causing significant degradation in its performance. This can be caused by overheating or gradual loss of efficiency due to the forward bias of the diode.

In a forward-biased diode, when too much current flows, it causes an increase in temperature which results in thermal runaway and failure of the device. The saturation current depends on various factors such as temperature, frequency, size of diodes, etc.

Main Characteristics Of Saturation Current of Diodes:

The saturation current of diodes is a very important parameter for the design and operation of power supplies, DC-to-DC converters, and other circuits. It is usually specified in terms of the forward voltage drop across the diode.

The main characteristics of the saturation current of diodes are:

  • It is the value of DC that can be maintained in a diode without any change in its forward voltage. The saturation current increases with temperature. This is because at high temperatures, the band gap energy increases, which reduces the barrier height at the depletion region.
  • This means that more carriers can cross over from n-type to p-type semiconductor material resulting in larger saturation currents. And the saturation current of a diode depends upon its manufacturer and the type of diode itself.
  • It is the value of DC that can be maintained in a diode without any change in its forward voltage. The most common diode is a p-n junction diode with a large depletion region and depletion layer near the n-type semiconductor material (n-type semiconductor material has greater electron density than holes).
  • As mentioned previously, this depletion region causes an effective increase in series resistance that decreases as forward voltages increase. This occurs because there is less overlap between electrons and holes in the depletion region; therefore, fewer electrons can contribute to the conduction current as voltage increases until they were completely separate.

How To Use The Saturation Current of A Diode?

The saturation current of a diode is one of the most important parameters in the design of a diode circuit, and it has some special characteristics.

To begin with, the saturation current of a diode is constant over a wide range of voltages. For example, when the forward voltage drops from 1 V to 0.5 V, the saturation current of an ideal diode does not change significantly.

What’s more, when there is any reverse voltage on an ideal diode, it cannot pass through its saturation current because it will be shorted out by the reverse voltage. In other words, there is no saturation current in the reverse direction for an ideal diode under reverse bias conditions. That’s why most diodes are said to be “one-way devices”.

Generally, if you have two diodes connected back to back with their cathodes tied together and then apply a forward bias voltage across them, they will conduct until one of them reaches its own saturation current value.

How To Choose The Saturation Current of A Diode?

When you are choosing a diode, the saturation current is one of the most important parameters to consider. Many circuits use diodes for switching and rectification, so it is essential that you choose a diode with the right amount of current handling capacity.

The saturation current is the maximum amount of current that a diode can handle without overheating. This is why it is so important when selecting diodes for your circuit. If a diode has too little saturation current, then it will overheat and fail when put under heavy load conditions. If it has too much saturation current then no matter how much power flows through it, it will not overheat.

If you want to purchase the saturation current of a diode, you can choose the company EASYIEE help. They are a professional manufacturer in China. They focus on this industry for many years and have rich experience. What’s more, they have our own factory in Shenzhen City.

The company has its own R&D team and production workshop. They provide all kinds of electronic parts with high quality and competitive prices. Their products are widely used in communication, transportation, energy, and other fields. The company offers the best product quality and service for customers throughout the world.


The saturation current of a diode is the current that must be applied to a diode in order for it to become fully forward-biased and operate at its maximum possible voltage-current relationship.

Saturation current is a large-scale indicator of the diode’s ability to conduct electric current. Generally, the larger the saturation current a diode can support, the more efficient it is as a switching element or as an amplifier. But different manufacturers can have their unique ways of detecting saturation current, so you need to be careful when comparing results from different websites.