Dry goods【Main parameters of SMD inductors】

SMD inductors are also called power inductors, high current inductors and surface mount high power inductors. It has the characteristics of 

miniaturization, high quality, high energy storage and low resistance. It mainly plays a role of filtering and oscillation in the circuit. 

Inductance Normally, a coil with a magnetic core has a larger inductance than a coil without a magnetic core. The more the coil turns, the 

denser the coil and the greater the inductance. The greater the permeability of the core, the greater the inductance. The basic unit of 

inductance is Henry (Henry for short), represented by the letter "H". Commonly used units are millihenry (mH) and microhenry (μH), the 

relationship between them is: 1H=1000mH; 1mH=1000μH .

Distributed capacitance

The smaller the distributed capacitance between the coil and the magnetic core, and the capacitance between the turns of the coil, the better 

the stability.

Rated current

It refers to the maximum current value allowed by the SMD inductor when it is working normally, and the current when it is operated at the 

rated power. If the working current exceeds the rated current, it will cause burnout.

Allowable deviation

The inductance unit is followed by an English letter to indicate its allowable deviation, for example: 560uHK means the nominal inductance is 

560uH, the allowable deviation is 10%, and the text symbol is the French text symbol method, which is the nominal value and allowable 

deviation of the inductors The value is marked on the inductors with a combination of numbers and text symbols according to a predetermined 

law. For example: 4N7 means the inductance is 4.7nH, 4R7 means the inductance is 4.7uH; 47N means the inductance is 47nH, 6R8 means the 

inductance is 6.8uH.

Quality factor

The quality factor is also called the Q value or the figure of merit, and it is the main parameter to measure the quality of the inductors. 

It refers to the ratio of the inductive reactance presented by the SMD inductors to its equivalent loss resistance when working under a 

certain frequency of AC voltage. The higher the Q value, the smaller the loss and the higher the efficiency .