The new IEEE 802.3bt Power over Ethernet (PoE) standard allows standard Ethernet cables to carry up to 90 W of power, opening the doors to almost any Ethernet device being powered by a single Ethernet cable. Yet despite being in the market for over a decade, PoE technology is often shrouded in a cloud of mystery and confusion.
While the latest standard adds new features beyond increased power delivery, it is also more complex than previous standards. But take heart, this article will introduce you to PoE basics and some new features in the 802.3bt standard, as well as give you enough background to make complex PoE white papers, app notes, and datasheets understandable.