Fully Autonomous IEEE 802.3af Power over Ethernet Midspan PSE Requires No Microcontroller

摘要

The IEEE802~(~R).3af Power over Ethernet (PoE) standard defines how power will be delivered over CAT5 lines. Despite the differences between legacy devices and those that adhere to the new standard, there is no need to completely replace existing systems. The nominal 48V required by powered devices (PDs) can be delivered by midspan power sourcing equipment (PSE), which is connected to the front end in series with legacy routers and switches. The LTC~(~R)4259A is a quad PSE controller designed for both endpoint and midspan PSEs that integrates PD signature detection, power level classification, AC and DC disconnect detection and current limit without the need for a microcontroller.