CEP125NP-4R0MC-H Inductors, Coils, Chokes

Fixed Inductors

Inductors, also known as coils, chokes or reactors, are components used in electrical circuits which stores energy in a magnetic field when electrical current passes through them. They are mostly used as parts of filters, tuners, oscillators and transformers in electrical power systems and consumer electronics. Among all inductors, Fixed Inductors, as one of the most common types, are specified to have an inductance value that won’t change under varying conditions of temperature, current, or time. In this article, CEP125NP-4R0MC-H, a typical Fixed Inductor, is to be discussed in terms of its application field and working principle.

CEP125NP-4R0MC-H

CEP125NP-4R0MC-H is a SMD (Surface Mount Device) type Fixed Inductor manufactured by Coilcraft. Its inductance value lies between 4.0uH and 4.5uH with the nominal value being 4.0uH; the electrical resistance is less than 125mohm while the DC current is up to 1.40A. It also comes with a tolerance of ±20%.

Application Field

CEP125NP-4R0MC-H usually finds its application in frequency compensation circuit of switching power supply as its low resistance will not increase the power loss. Besides, by using CEP125NP-4R0MC-H in two different circuits, the ringing frequency will become twice of that before, which can be used to reduce the EMI (Electromagnetic Interference). In addition, CEP125NP-4R0MC-H is also ideal for applications in resonance circuits and communication filters with the design frequency under 30MHz.

Working Principle

The working of Fixed Inductor is based on the property of inductance, which is the tendency of electrical current through an inductor to oppose change. According to Faraday’s law, electromotive force (e.m.f) is induced in a coil when the current flowing through it varies. Thus, when an alternating current passes though the CEP125NP-4R0MC-H, the changing current produces a voltage called Back Electromotive Force (Back e.m.f) that is proportional to the rate of change. The generated back e.m.f acts against the source voltage, increasing the total opposition to current flow. In other words, when the alternating current passes CEP125NP-4R0MC-H, the CEP125NP-4R0MC-H will cause the current to be slowed or lagged.

Conclusion

As mentioned earlier, CEP125NP-4R0MC-H is a type of Fixed Inductors, which is designed for use in frequency compensation, resonance circuits and communication filter. Its working principle is based on Faraday’s law and the back e.m.f induced against the source voltage.