概述

　　以太网供电系统POE是指通过网线向终端受电设备提供电能。现在网络设备越来越多，供电端需要提供更多的供电端口，供电功率也需求越来越大，对防雷击浪涌的要求更高，例如需求 16口，24口甚至更多。但是一般单颗的 PSE芯片只支持 4个供电端口，供电功率等级只支持 IEEE802.3 AF标准。本方案可以提供单芯片 8个供电端口，±4KV 共模，±2KV 差模surge防护等级，支持IEEE802.3 AT标准，以及支持更为优化带 I2C 数字隔离的功率管理系统。

　　优势

　　• 高集成度PSE供电控制器(Si3459),单芯片支持高达8个供电端口，支持IEEE802.3 AT 标准;片上集成DC/DC控制器和LDO电压调节器，满足30W内供电功率，还可对外输出3.3V电压给其他芯片使用，高集成度简化BOM成本和电路设计。

【Si3459】

Features

> Octal-Port Power Sourcing

Equipment (PSE) controller

> IEEE 802.3at Type I and IIcompliant

> Port priority shutdown control

> Adds enhanced features formaximum design flexibility:

》Per-port current and voltagemonitoring

》PoE+ support with programmablecurrent limits

》Multi-point detection

》Programmable power MOSFETgate drive control

》Configurable watchdog timerenables failsafe operation

> Maskable interrupt pin

> Comprehensive fault protectioncircuitry includes:

》Power undervoltage lockout

》Output current limit and shortcircuitprotection

》Thermal overload detection

> Pin-programmable AUTO modes

> Extended operating temp range:–40 to +85 °C

> 56-pin QFN package(RoHS-compliant)

> On-chip dc-dc converter enablessingle-rail power operation

Applications

> IEEE Power Sourcing Equipment(PSE)

> Power over Ethernet Switches

> IP Phone Systems

> Smartgrid Switches

> Ruggedized and IndustrialSwitches

Description

The Si3459 is a fully-programmable, eight-port power management controller for IEEE 802.3 compliant Power Sourcing Equipment (PSE).Designed for use in PSE endpoint (switches), the Si3459 integrates eight independent ports, each with IEEE-required powered device (PD) detection and classification functionality. In addition, the Si3459 features a

fully-programmable architecture that enables powered device (PD) disconnect using a dc sense algorithm, a robust multipoint detection algorithm, software-configurable per-port current and voltage monitoring,and programmable current limits to support the IEEE 802.3at standard. Intelligent protection circuitry includes input undervoltage detection, output current limit, and short-circuit protection. The Si3459 operates by host processor control through a three-wire, I2C-compatible serial

interface. Independent serial data input and output pins enable highvoltage isolation through external isolators. An interrupt pin is used to alert the host processor of various status and fault conditions. The device also supports pin-programmable AUTO modes for autonomous operation, without the need for a host processor. The Si3459 also features an onchip dc-dc converter for creating the digital voltage rail from the PoE voltage, thus enabling single-rail power operation.

Si3459 16 端口中跨评估套件

Si3459-KIT

Si3459-KIT 用于 Si3459 PoE 子系统的详细工程评估。它能够启用芯片的寄存器级别控制和探索，以及丰富的图形用户界面 (GUI) 环境的端口状态和功耗监控。

基于寄存器的 PC 控制 GUI 是工程评估 Si3459 的功能和性能的理想 GUI。

目录

16 端口中跨参考设计

(2) Si3459 设备

Si8605 I²C+复位+中断隔离器

I²C 至 USB 通信板

1 类 PD 负载

2 类 PD 负载

所有连接器和电缆

Si3459 评估 GUI

Si3459 24 端口中跨评估套件

Si3459SMART24-KIT

Si3459SMART24-KIT 支持 UART 或 SPI 主机接口，包括简化系统设计的电源管理功能。一旦通过 USB 配置主机适配器，则基板可在不受主机控制情况下运行。基板作为完全单机 PSE 评估系统和参考设计进行操作。

目录

采用电源管理芯片的 24 端口中跨参考设计

(3) Si3459 设备

UART Si8651 隔离器

Si3484 电源管理 IC

UART 至 USB 通信板

1 类 PD 负载

2 类 PD 负载

所有连接器和电缆

电源管理评估 GUI

　　• 功率可达200-3000W的TVS二极管阵列(SMAJ等)，出色的电压箝位能力，符合各种国际标准，为系统提供高级别的雷击浪涌防护等级，增强产品可靠性。例如：±4KV 共模，±2KV 差模surge防护等级。

　　• 为POE供电控制器与功率管理芯片之间提供I2C通信隔离的数字隔离器(Si860x)，带双向数据通信通道，片内集成抗闩锁电路，解决使用两个单向且并行的光耦实现I2C隔离总线锁死问题;体积比光耦减少50%以上，简化电路设计且降低BOM成本。

　　POE (Power Over Ethernet)指的是在现有的以太网Cat.5布线基础架构不作任何改动的情况下，在为一些基于IP的终端(如IP电话机、无线局域网接入点AP、网络摄像机等)传输数据信号的同时，还能为此类设备提供直流供电的技术。POE技术能在确保现有结构化布线安全的同时保证现有网络的正常运作，最大限度地降低成本。

【Si860x】

Bidirectional I2C Isolators with Unidirectional Digital Channels

The Si860x series of isolators are single-package galvanic isolation solutions for I2C andSMBus serial port applications. These products are based on Silicon Labs proprietaryRF isolation technology and offer shorter propagation delays, lower power consumption,smaller installed size, and more stable operation with temperature and age versus optocouplers or other digital isolators.

All devices in this family include hot-swap, bidirectional SDA and/or SCL isolation channelswith open-drain, 35 mA sink capability that operate to a maximum frequency of 1.7MHz. The 8-pin version (Si8600) supports bidirectional SDA and SCL isolation; theSi8602 supports bidirectional SDA and unidirectional SCL isolation, and the 16-pin versions(Si8605, Si8606) feature two unidirectional isolation channels to support additionalsystem signals, such as interrupts or resets. All versions contain protection circuits toguard against data errors when an unpowered device is inserted into a powered system.

Small size, low installed cost, low power consumption, and short propagation delaysmake the Si860x family the optimum solution for isolating I2C and SMBus serial ports.

Automotive Grade is available for certain part numbers. These products are built usingautomotive-specific flows at all steps in the manufacturing process to ensure the robustnessand low defectivity required for automotive applications.

Industrial Applications

•

Isolated I2C, SMBus

• Power over Ethernet

• Motor Control Systems

• Hot-swap applications

• Intelligent Power systems Safety Regulatory Approvals

• UL 1577 recognized

• Up to 5000 VRMS for 1 minute

• CSA component notice 5A approval

• IEC 60950-1, 61010-1, 60601-1 (reinforced insulation)

• VDE certification conformity

• Si863xxT options certified to reinforced VDE 0884-10

• All other options certified to IEC 60747-5-5 and reinforced 60950-1

• CQC certification approval

• GB4943.1

Automotive Applications

• On-board chargers

• Battery management systems

• Charging stations

• Traction inverters

• Hybrid Electric Vehicles

• Battery Electric Vehicles

KEY FEATURES

• Independent, bidirectional SDA and SCL isolation channels

• Open drain outputs with 35 mA sink current

• Supports I2C clocks up to 1.7 MHz

• Unidirectional isolation channels support additional system signals (Si8605, Si8606)

• Up to 5000 VRMS isolation

• UL, CSA, VDE, CQC recognition

• 60-year life at rated working voltage

• High electromagnetic immunity

• Wide operating supply voltage

• 3.0 to 5.5 V

• Wide temperature range

• –40 to +125 °C

• Transient immunity 50 kV/µs

• AEC-Q100 qualification

• RoHS-compliant packages

• SOIC-8 narrow body

• SOIC-16 wide body

• SOIC-16 narrow body

• RoHS-compliant packages

• SOIC-16 wide body

• SOIC-16 narrow body

• SOIC-8 narrow body

• Automotive-grade OPNs available

• AIAG compliant PPAP documentationsupport

• IMDS and CAMDS listing support

Si860x系列

Si8600AB-B-IS

Si8600AC-B-IS

Si8600AD-B-IS

Si8602AB-B-IS

Si8602AC-B-IS

Si8602AD-B-IS

Si8605AB-B-IS1

Si8605AC-B-IS1

Si8605AD-B-IS

Si8606AC-B-IS1

Si8606AD-B-IS

Si8602AD-AS

Si8605AD-AS

       Si8606AD-AS

　　【PoE】

      PoE也被称为基于局域网的供电系统(PoL, Power over LAN )或有源以太网( Active Ethernet)，有时也被简称为以太网供电，这是利用现存标准以太网传输电缆的同时传送数据和电功率的最新标准规范，并保持了与现存以太网系统和用户的兼容性。IEEE 802.3af标准是基于以太网供电系统POE的新标准，它在IEEE 802.3的基础上增加了通过网线直接供电的相关标准，是现有以太网标准的扩展，也是第一个关于电源分配的国际标准。

　　IEEE在1999年开始制定该标准，最早参与的厂商有3Com, Intel, PowerDsine, Nortel, Mitel和National Semiconductor。但是，该标准的缺点一直制约着市场的扩大。直到2003年6月，IEEE批准了802. 3af标准，它明确规定了远程系统中的电力检测和控制事项，并对路由器、交换机和集线器通过以太网电缆向IP电话、安全系统以及无线LAN接入点等设备供电的方式进行了规定。IEEE 802.3af的发展包含了许多公司专家的努力，这也使得该标准可以在各方面得到检验。