Engineered for robust circuitry
An inductor, also called a choke or coil, is a two-terminal passive component that typically consists of an insulated copper wire, that is wound into a coil. The coil is wrapped around a core of either magnetic, or non-magnetic material. Many inductors, sometimes known as ferrite core inductors, have a ferromagnetic core that is made of iron or ferrite which is designed to increase the magnetic field, and as a result the inductance. Other inductors, known as air core inductors, have a non-magnetic core, typically of plastic, ceramic, or just air. Air core coils have lower inductance than ferromagnetic core coils but are often used at high frequencies because they are virtually free from energy losses called core losses that occur in ferromagnetic cores, which increase with frequency.
As electric current flows through the coil, the inductor temporarily stores the energy in the magnetic field. When the current changes the magnetic field induces an electromotive force (voltage) in the conductor which opposes the change in current which created it, removing any ripples in the current flow. Inductors, along with capacitors and resistors, are one of the three passive linear circuit elements that make up electronic circuits.
Inductors are used in electronic devices and electrical power for applications. This includes applications engineered for choking, blocking, or filtering high frequency noise in electrical circuits, storing and transferring energy in power converters, impedance matching, and making tuned oscillators or LC circuits. Inductors are widely used in alternating current (AC) equipment, especially in radio equipment.
Chokes, a type of inductor, are used in radio equipment, whereby AC is blocked while direct current (DC) is allowed to pass. Inductors are used with capacitors to make tuned circuits, which are used to tune radio and TV receivers, as well as in electronic filters to separate signals that have different frequencies.
Types of Inductors
Low frequency inductors are created like transformers and have cores made of electrical steel that are laminated to help prevent eddy currents. For cores that are above audio frequencies, soft ferrites are used because they do not cause high energy losses at high frequencies that are typical of iron alloys. Inductors are available in many shapes. Some have an adjustable core that enables inductance changing. Inductors designed to block very high frequencies may be made by stringing a ferrite bead on a wire.
Small inductors can be etched directly onto a print circuit board (PCB) by making the trace in a spiral pattern. These inductors use a planar core. By using the same process that is used to make interconnects, small value inductors can be built on integrated circuits. Because on-die inductors allow only low inductances and low power dissipation, they are currently only used for high frequency RF circuits.
Shielded inductors are used in power regulation systems, lighting, and other systems that necessitate low-noise operating environments. These can be partially or fully shielded. Employing induction coils and repeating transformers shielding of inductors in close range reduces the chance of circuit cross talk in telecommunication circuits.
Miniature Power Inductors
TE Connectivity (TE)’s miniature SMD power inductors are designed with special ferrite cores for increased performance and reliability. They are offered in two variations viz. 3627 for low DC Resistance and 3627 C for low DC resistance & high current capability with high impedance characteristics, which make them a good choice for using as a choke coil in DC power supply circuits.