On size and magnetics: Why small efficient power inductors are rare
On size and magnetics: Why small efficient power inductors are rare
复制标题
关于尺寸和磁性：为什么小型高效功率电感器很少见
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
P. Kyaw
中科院分区：
文献类型：
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作者：
C. Sullivan;B. Reese;A. Stein;P. Kyaw
在功率转换器所需的三种主要元件类型（开关、电容和电感）中，最难集成到半导体芯片或平面封装中的是电感。这一困难部分来自于磁性材料的工艺兼容性挑战，并且由于大多数类型的电子产品不需要电感器，因此开发工作相对较少，这一事实加剧了这一困难。但一个更根本的挑战是磁性性能随尺寸变化的方式。电容器和半导体器件可以由数千个并联的小电池制成，但这种方法会严重削弱磁性元件的性能。磁性的比例关系进行了探讨，以证明小尺寸和低剖面磁性的固有困难。所考虑的情况包括那些受趋肤效应和邻近效应限制的绕组设计，以及那些受效率和散热限制的绕组设计。小型磁性元件通常受限于效率而非散热。与效率的约束，并考虑高频绕组损耗的影响，它表明，功率密度通常缩放为线性尺寸缩放因子的五次方。
Of the three main component types needed in power converters-switches, capacitors and inductors-the most difficult to integrate on a semiconductor chip or in a planar package is the inductors. This difficulty arises partly from process compatibility challenges with magnetic materials, and is exacerbated by the fact that, because most types of electronics don't need inductors, there has been relatively little development effort. But a more fundamental challenge is the way magnetics performance scales with size. Capacitors and semiconductor devices can be made from thousands of small cells connected in parallel, but that approach would severely undercut the performance of magnetic components. Scaling relationships for magnetics are explored to demonstrate the inherent difficulty of small size and low profile magnetics. Cases considered include those with winding designs limited by skin and proximity effect and those constrained by efficiency and thermal dissipation. Small-scale magnetic components are typically limited by efficiency rather than heat dissipation. With efficiency constrained, and considering high frequency winding loss effects, it is shown that power density typically scales as the linear dimension scaling factor to the fifth power.