Selection Criteria for Chip Inductors

Inductor is a common electronic component in SMT chip. SMD inductor is also called power inductor, high current inductor and surface mount high power inductor. It has the characteristics of miniaturization, high quality, high energy storage and low resistance. It is one of the basic electronic components of electronic processing plants.

Inductors can be made from a coiled core of conductive material, typically copper wire, but the core can also be removed or replaced with a ferromagnetic material. A core material with a higher permeability than air can confine the magnetic field more tightly around the inductive element, thereby increasing the inductance. There are many kinds of inductors, most of which are made of enamel coated wire around a ferrite spool, and some protective inductors put the coil completely inside the ferrite. The core of some inductive components can be adjusted, thereby changing the size of the inductance. Small inductors can be etched directly on the PCB, using a method of laying spiral traces. Small value inductors can also be fabricated in integrated circuits using the same process used to fabricate transistors. In these applications, aluminum interconnects are often used as the conductive material. Regardless of the method used, the most common application based on practical constraints is a circuit called a “rotator”, which uses a capacitive and active element to exhibit the same behavior as an inductive element. Inductive components used to isolate high frequencies are often constructed with a wire that passes through a magnetic column or bead. Inductance is the ratio of the magnetic flux of the wire to the current that produces this magnetic flux when an alternating current is passed through the wire, which generates an alternating magnetic flux in and around the wire. So how to choose chip inductors in electronic processing:

1. During maintenance, it is not possible to replace the chip inductor with the amount of the inductor alone. In order to ensure the operating characteristics, it is also necessary to understand the operating frequency range of the chip inductor.

2. The precision of most of the chip inductors available in the market is ±10%. If the specified precision is higher than ±5%, it must be ordered in advance.

3. The total width of the chip inductor should be lower than the total width of the inductor, so as to avoid excessive welding material causing excessive ground stress during water cooling to change the inductor value.

4. Some chip inductors can be welded by reflow oven and wave soldering, but some chip inductors cannot be welded by wave soldering.

5. The allowable amount of current is an index value of the chip inductance. When the power supply circuit has to bear a large amount of current, this index value of the capacitor must be taken into account.

6. In the communication equipment working in the frequency range of 150~900MHz, the common wire-wound inductance. In the frequency power circuit of about 1GHz, microwave heating must be used for high-frequency inductors.

7. The appearance design and specification of the chip inductor are similar, and the appearance design has no obvious logo. When hand-soldering or hand-making the patch, you must be very careful not to make the wrong part or take the wrong part.

8. Different products use different diameters of magnetic coils. Even if the same amount of inductor is used, the resistance measurement displayed is not the same. In the high frequency control loop, the resistance measurement is very harmful to the Q value, so pay attention when designing the scheme.

9. When a power inductor is used in a DC/DC converter, the size of the inductor will immediately affect the working attitude of the power supply circuit. Combined with the actual situation, the method of adjusting the magnetic coil can usually be used to change the amount of the inductor to achieve the best practical effect.

10. There are three common chip inductors at this stage: the first one is high frequency inductors for microwave heating. It is suitable for applications in the frequency band around 1GHz. The second is high frequency chip inductors. It is suitable for series resonance control loop and frequency selective power supply circuit. The third, practical inductors. It is generally applicable to power circuits of tens of megahertz.