Powering terminal devices via mains connection in compliance with EMC requirements
Würth Elektronik presents the reference design RD022 “GB-PoE+-Ethernet-USB-Adapter” available on we-online RD022. Typically, devices networked via Ethernet rely on a separate power source. However, if these terminals can operate with low power consumption, “Power Over Ethernet” (PoE) technology is an alternative and data transmission and power can be carried out over a network cable.
Low-power devices such as IP cameras, VoIP phones, WLAN routers, network switches, LED lighting or access systems are suitable for power supply over Ethernet. The new reference design RD022 from Würth Elektronik shows how it can be implemented in accordance with EMC requirements, with a possible power of up to 25 W. The "GB-PoE+-Ethernet-USB-Adapter" is based on the reference design of a 1 gigabit USB Ethernet adapter without PoE function, which is described in detail in RD016 we-online RD016).
The "GB-PoE+-Ethernet-USB-Adapter" offers three interfaces: a USB C interface (USB 3.1), a 45 GB RJ1 Ethernet interface with integrated PoE function, as well as a connection for a DC/DC converter with a voltage adjustable output from 6 to 18 V and a maximum output power of 25 W. The board has been developed to make it easier for customers to access PoE technology. The reference design allows you to become familiar with the PoE technology, signals, interface structure, power-up, and detection of a gigabit PoE interface. Provides the hardware layout for the power supply equipment (PSE) and powered device (PD), and explains the layout and structure of the adapter board: power loops, USB controller and interface, Ethernet interface as well as power supply ( PoE). Special care has been taken to ensure that the design meets electromagnetic compatibility requirements.
