The evaluation board is designed for PoE applications, offering a 12V/6A output and incorporating power management and efficiency features that support gigabit systems.
Power over Ethernet (PoE) technology enhances the functionality and deployment of Powered Devices (PDs) by streamlining power delivery alongside data over a single network cable. This integrated approach offers numerous advantages, including centralized power management, reduced installation costs, increased safety, and greater flexibility in device placement. Such capabilities are pivotal in facilitating the deployment of network devices such as IP cameras, wireless access points, and VoIP phones, where conventional power solutions may fall short. The incorporation of PoE ensures that devices receive stable and reliable power and benefit from the ease of remote management and monitoring, making it an indispensable technology in modern networked environments. The Si34071 isolated forward topology evaluation board serves as a reference design by Skyworks for a power supply within a Power over Ethernet (PoE) Powered Device (PD) application.
The Si34071-FW-12V-C8 model delivers an isolated output of 12 V/6 A. The board incorporates the Si34071 IC, which includes an IEEE 802.03bt-compatible PoE interface and a current-controlled DC/DC converter. The device boasts various critical features, including compliance with IEEE 802.3bt and EMI standards, achieving an impressive 91% efficiency. It is highly integrated and includes a straightforward 9600-baud UART interface for simple communication. Additional features include an Autoclass feature, integrated transient overvoltage protection, and thermal shutdown protection to ensure reliable operation under various conditions. The compact unit is encapsulated in a 5 x 5 mm 32-pin QFN package, optimizing space without sacrificing functionality.
The evaluation board is designed specifically for PoE applications, offering a powerful 12V/6A output. The reference design integrates the chip, which provides both IEEE 802.3bt interfacing and power supply control within a single solution, streamlining the setup. The board’s DC/DC converter is versatile, featuring two distinct operational modes for efficiency optimization: the reset winding forward mode for low-power scenarios and the active clamp forward mode when high power is required. The Si34071 converter seamlessly handles the transition between these modes. Additionally, using input FET bridges enhances the system’s overall efficiency, ensuring reliable and effective power management in varying operational conditions.
Ethernet data and power are supplied to the board via the PoE+Data RJ45 connector. Although the board does not support Ethernet data transmission, it conveniently connects the secondary-side data from the Ethernet transformer to another connector. This setup is compatible with Gigabit systems, supporting 10/100/1000 Mbps speeds.
Skyworks has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and other data. You can find additional data about the reference design on the company’s website. To read more about this reference design, click here.
