【摘要】 本文对IEEE802.3af-2003标准作了简单的介绍,该标准定义了以太网供电技术,众多低功耗以太网设备将从该技术中获益。该标准介绍了两种供电方式,即端跨式供电方式和中跨式供电方式。文中对现有的几种以太网供电方案和芯片特性做了介绍和分析,这对于针对特定的以太网供电系统的方案选择是非常有用的,另外还结合基金会现场总线HSE仪表供电方面的应用,重点介绍了其中的一种实现方式。更多还原

【Abstract】 This paper introduces a newly approved specification called IEEE802.3af-2003 which defines the PoE(Power over Ethernet) method, and a lot of low-power Ethernet equipments will benefit from it. It introduces twoways to power, endspan and midspan. Some PoE design and chip feature are also described and analyzed in thispaper which makes it helpful to choose the blueprint for a special PoE system. Besides, it emphasizes the realizationof this technique for FF HSE instrument.更多还原