Building a PoE Power Subsystem

摘要

Globally, many more devices are getting networked. In fact, being connected to an IP network is increasingly the only option to control and manage the device. As devices get networked, it becomes very convenient to run them on just one Ethernet cable that provides both the connectivity and the power. Besides, having the power delivered via a centrally managed switch allows for other enhancements such as remote ON/OFF and uninterrupted operation even in the case of a local power outage. With the advent of the newest IEEE 802.3bt PoE standard, even more types of devices can now be powered via PoE. As the amount of power delivered increases, so does the need for higher efficiency and wider input voltage ranges to accommodate the complex power system designs. This requires careful considerations regarding the selection of both the PD controller as well as the DC-DC converter to generate the required regulated voltage to be used by the system.