材料的進(jìn)步: 新一代的功率電感器

　　設(shè)計(jì)師為今天的高容量移動(dòng)市場(chǎng)建設(shè)功率電感器面臨兩難困境。一方面，市場(chǎng)要求更高的性能系統(tǒng)具有額外的功能運(yùn)行在更高的電流水平。另一方面，它迫使產(chǎn)品設(shè)計(jì)師擠壓額外的功能變成一個(gè)越來越小的包。以智能手機(jī)市場(chǎng)為例。今天的手機(jī)正在迅速遷移雙核處理器，運(yùn)行在1和1.5 GHz之間，四核處理器運(yùn)行在超過2千兆赫。因此，手機(jī)設(shè)計(jì)人員需要扼流線圈的電源電路，能夠支持更高的工作電流，用于提供手機(jī)的新功能。與此同時(shí)，手機(jī)的設(shè)計(jì)正變得越來越小，越來越薄，因此，手機(jī)設(shè)計(jì)師也需要足夠小的線圈，以適應(yīng)他們的手機(jī)萎縮的足跡。

　　同樣的趨勢(shì)可以在平板電腦設(shè)計(jì)中看到。今天的客戶需求更大，更高性能的屏幕。他們也期待更輕，更薄的藥片。例如，原來的蘋果iPad平板電腦有0.5英寸厚。在0.29英寸，最新的iPad Mini幾乎一半厚。因此，平板電腦設(shè)計(jì)師需要扼流圈能夠支持更高水平的電流，但小到足以適應(yīng)非常低的配置文件所使用的今天的領(lǐng)先產(chǎn)品。

　　Unfortunately， those requirements run counter to traditional principles of choke coil design. Typically， choke coils are comprised of ferrite material. Since the saturation flux density of ferrite is not very high， the DC bias characteristics decline due to magnetic saturation when the choke coil is reduced in size. As a result， higher currents cannot pass through the choke. That is why designers are turning to inductors that use compacted metal powder made of high-saturation magnetic flux iron-based metal magnetic particles and an organic binder. In these products， the metal magnetic particles and the coil are formed at the same time. Then the binder is solidified and used to provide insulation between the metal particles.