Regarding the inductance characteristics, the more you know these points, the better.

1: I-shaped inductor; 2: color-ring inductor; 3: air-core inductor: 4: toroidal coil inductance; 5: patch laminated high-frequency inductor; 6: magnetic bar inductance; 7: SMD chip power inductor; : piercing magnetic beads 9: patch magnetic beads; 10: patch high-frequency transformer, plug-in high-frequency transformer;

Inductive sorting, I think it is the product of application, physics, technology, materials, process, cost, ... and so on. The products that are currently on the market are optimized products that are integrated after the above compromises. Please pay attention to the words "one by one", which means that the current products are not the ultimate products! This means that the space for our development is infinitely broad, as long as we are willing to understand and study hard, better. Products will appear one after another.

Let me give you an example. Customers want to make the most efficient use of space. They like square-shaped products most. The central axis of our inductors is the most convenient. The most effective process shape is round. How to put round things on the square. Space, to maximize the effect, this is compromise!

A simple answer to the question of characteristics, I hope to help everyone.

1: I-shaped inductor

Its predecessor is a flex-type chip inductor, and the I-shaped inductor is an improvement. The baffle effectively enhances the energy storage capacity, changes the EMI direction and size, and reduces the RDC. It can also be said to be a compromise between signal communication inductance and POWER inductance.

SMD type I-shaped inductors are mainly used for small power switching of several hundred kHz to one or two MHz, such as digital camera LED boost, ADSL, etc. for lower frequency part of signal processing or POWER use, it The Q value is 20,30, which is quite suitable for signal processing; RDC is lower than the flex-line chip inductor, and it is very easy to use as POWER. Of course, a large I-shaped inductor is definitely used for POWER. .

The biggest drawback of the I-shaped inductor is still the open magnetic circuit, which has the problem of EMI. In addition, the noise problem is larger than the flex-type chip inductor. I personally think that the I-shaped inductor is definitely not an optimized structure, and the improvement space is still very large!

2: color ring inductance

The color ring inductance is the processing of the simplest rod inductor, mainly used for signal processing. There is no big difference between the characteristics of the rod-shaped inductor and the rod-shaped inductor. Only some solid objects are added, and some colors are added to facilitate the resolution of the sense value. Since the unit price is very cheap, the current volume is not considered, and the electronic products of the plug-in are still available. , using color ring inductance is still much. Because it is plug-in, and too traditional, it is time to get rid of the era.

3: Air core inductor

Hollow inductors are mainly used for signal processing, used for resonance, reception, transmission, etc. Air can be applied to very high frequency products. Therefore, many products with less variability are still in use. Because air is not the best material for fixed coils, development is limited in the trend of increasingly demanding products!

4: toroidal coil inductance

The toroidal coil inductance is a very ideal shape in the theory of inductance, closed magnetic circuit, little EMI problem, making full use of the magnetic circuit, easy to calculate, almost theoretical benefit, full return coil inductance, but, has one of the biggest drawbacks It is not good to scratch the line, the process is mostly manual.

Now there are many Chinese, girls are fine-handed, but who wants to let young and lively girls waste youth! Not too late in the morning! But with the machine, the competitiveness of the ring-shaped wire has yet to be mechanically and electronically controlled. The engineer came to upgrade. Although the toroidal coil inductance is a very ideal shape in the inductor, it is mainly used for manual signal processing. Because it is used for signal processing, it is less used, but the small and small toroidal coil inductance is still very large. It is mainly used in high-frequency, high-sensitivity communication products.

The maximum amount of toroidal coil inductance is made of iron powder core material, mixed with resin, etc., so that the Air gap is evenly distributed inside the iron powder core, and it has inductance, and it has certain sensitivity. When we see the word Air gap It is known to be used in power. Therefore, the iron powder core toroidal coil inductance is the most commonly used one of power inductors, and the IDC can reach more than 20 amps.

I think that the improved space of the toroidal coil inductor is very large, so I can develop and think in this direction.

The advantage of the iron powder core toroidal coil inductor is the ring shape, but the disadvantage is also the ring shape. I have said before that the user's favorite shape is square. Therefore, under the compromise, the toroidal coil inductance is not the most advantageous.

5: SMD laminated high frequency inductor

The laminated high-frequency inductor is actually a hollow inductor. The characteristics are exactly the same, but because it is easy to fix, it can be miniaturized.

The laminated high-frequency inductor is compared with the hollow inductor. Because the air is not a good fixture, the relative permeability of the air is one. It is very useful at high frequencies. Therefore, it is good to find some relative permeability. The fixture, that's not very good.

In fact, most of the world's material, the permeability is one, the cheapest is the stone, the material of the high-frequency inductor of the laminated layer is the stone, the stone is the silicon! The material of the aluminum oxide, etc. The same purpose.

In short, the purpose of the laminated high-frequency inductor material is to make a laminated chip to facilitate the printed circuit. We don't want the material of the laminated high-frequency inductor to have characteristics. We hope that it has no features at all. Therefore, the high-frequency inductance of the laminated layer is completely like an air-core coil, and since it can be fixed, the variation is very small, and in the manufacturing process, since the lamination process can be miniaturized as much as possible. Z=2*pi]*frequency*inductance value, 2 and pi is constant, regardless of them, the same impedance, the higher the frequency, the smaller the inductance value, the frequency of communication products is getting higher and higher, which means Value requirements are getting smaller and smaller.

The smaller the sense value, the smaller the size of the magnet can be made, and the magnetic material with high magnetic permeability is not needed. With air, it can be used with stones. Therefore, the use of high-frequency inductors with laminated layers must be more and more. This is an inevitable trend of human development.

Compared with the high-frequency inductance of the chip stack and the high-frequency inductance of the patch, the Q value of the laminated high-frequency inductor is not high enough, which is the biggest disadvantage, but I can confirm that the patch is on the market now. The high-frequency inductance Q value is definitely not the limit of this product, so the space for improvement is still very broad. In addition, because the variation requirements of high-frequency products are very strict, the change of material to temperature is also an important reason for the high-frequency inductance of Taiwan and China patch laminated layers, which cannot be strongly confronted with Japanese!

Finally, because the sense value will become smaller and smaller, the accuracy requirements will be higher and higher, the patch laminated high-frequency inductor will replace the patch flex-type high-frequency inductor, Nanhai Eleven forecast, 5 to 10 years later, SMD film high frequency inductors will also replace patch high frequency inductors. Research and market direction, we must catch it!

6: Magnetic bar inductance

The magnetic bar inductance is the reinforcement of the hollow inductor. The inductance value is proportional to the magnetic permeability. The plug magnetic material enters the air-core coil, and the inductance value, Q value, etc. are greatly increased. Benefits, I imagined myself. If you can't figure it out, or don't want to think about it, you should change it early! Magnetic bar inductor is the simplest and most basic inductor. What is the application of inductor from 30 to 100 years ago? The characteristics are also true.

7: SMD chip power inductor

The main focus of SMD chip power inductors is to emphasize energy storage and less LOSS.

8: wear magnetic beads

The core bead is the resistor. The inductor is a low-pass component that allows low frequencies to pass through and blocks high frequencies.

9: SMD beads

SMD magnetic beads are the next generation of magnetic beads.

10: SMD high frequency transformer, plug-in high frequency transformer

High frequency transformer, generally used for switching power supply