STEVAL-POE002V1: 5V @ 8A, Synchronous Flyback Converter, IEEE 802.3bt

Summary

The STEVAL-POE002V1 reference design is a two-stage converter for a powered device (PD), and is able to deliver up to 40 W (5V @ 8A) DC from appropriate 4-pair PoE power sourcing equipment (PSE), or an external auxiliary supply.

The first stage is the Ethernet interface is based on the PM8805 controller with integrated full active bridge rectification. The PoE controller is compliant with the third generation IEEE 802.3bt specification (as well as the preceding 802.3af/at standards), with improved features and increased power capacity that allow new application possibilities for PoE networks, including point of sales and retail logistics devices.

The second stage is the DC-DC converter designed around a fixed frequency flyback topology managed by the configurable PM8804 PWM controller, with secondary synchronous rectification via a gate driver transformer.

Specifications

Manufacturer	STMicroelectronics
Category	Power Management
Sub-Category	POE - Power Over Ethernet
Eval Board Part Number	497-18320-ND
Eval Board Supplier	STMicroelectronics
Eval Board	Normally In Stock
Compliance	IEEE 802.3bt Type 3
Outputs and Type	1 Non-Isolated
Voltage Out	5 V
Current Out	8 A
Voltage In	40 ~ 60 V
Efficiency @ Conditions	>90%, 48V in, 5V @ 3 ~ 8 A
Internal Switch	Yes
Features	Soft Start Thermal Protection
Switching Frequency	280 kHz
Component Count + Extras	232 + 4
Application / Target Market	PoE, Power Over Ethernet
Design Author	STMicroelectronics
Main I.C. Base Part	PM8804 PM8805
Date Created By Author	2018-10
Date Added To Library	2019-06