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How To Choose The Perfect Inductor?

How To Choose The Perfect Inductor?

Inductors are two-terminal electrical components designed to oppose the current passing through them. They store energy in the form of magnetic fields when current flows through them, and then oppose any change in the current by inducing and electromotive force. These components are primarily used for signal processing and analog circuits. They can be estimated as an open circuit for AC signals, and short circuits for DC signals. There are various types of inductors available that differ in performance, size, and cost. Choosing the right type of inductor for your application is imperative. Although you may know that Miracle Electronics is the best inductor coil manufacturer in India, where you must make your purchase from, but you may not know about the factors that you must consider while selecting your inductor. So, here are a few elements you must consider in order to choose the perfect inductor for your application.

Inductor size

Power circuit applications use large-sized inductors that are used in correspondence with filter capacitors. On the other hand, RF applications use small-sized ferrite core inductors as the power requirement in such cases is very less. So, you can clearly see that the inductor size plays a very important role while deciding the choice of the inductor for your application.


Tolerance is measured as the variation in the inductance value of an inductor in real as compared to the specified value in the data sheet. Such tolerance can result in unwanted shift in frequency selection of an RF filter.

Saturation current

Saturation current is the DC current that causes inductance drop, in relation to the magnetic properties of the inductor. The inductance drops by a specified value because the core has the capacity to store only a certain amount of magnetic flux density.


DC resistance

DC resistance is the resistance inbuilt within the metal conductor of the inductor, which is an important parameter in DC-DC converters because the resistance leads to I2R losses, thus reducing the efficiency. This DC resistance can be modeled as a resistor in series with the inductor.


The shielded components within an inductor can reduce magnetic coupling between components, which is an effective solution in space constrained applications.

Application to be used in

The inductor to be selected must meet the circuit requirements and also improve the performance. The two main applications that inductors are used in include power electronics and RF circuits. Understanding the requirements of the application can help choose the right type of inductor.

  • For power electronics, the maximum and incremental currents need to be considered. Maximum current is when the inductor’s current level exceeds the temperature of the application device. And, incremental current is the current level where the inductance is reduced.
  • For RF applications, you need to consider the Quality factor and self-resonant frequency (SRF). The Quality factor is the ratio of an inductor’s reactance to the effective resistance, which impacts the sharpness of the center frequency in an LC circuit. And, SRF is the frequency at which the inductor stops working as an inductor. This is why SRF should be chosen such that it exceeds the operating frequency of the circuit. Generally, high value of Quality factor and lowest value of SRF are preferred.

You can now choose the best inductor for your application, considering these important factors. Also, you must always check the data sheets provided by the manufacturer to confirm the specifications of the inductor.

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