标准以外的高功率PoE解决方案

引言 IEEE 802.3af以太网供电(PoE)标准于2003年6月批准通过.此后,诸如IP电话与无线LAN接入点等众多应用纷纷开始遵从这一最新标准.PoE市场中新推出了用于以太网线缆两端的几种PoE电源控制器.例如,TPS2383A是符合IEEE 802.3af标准的控制器,用于线缆的供电设备(PSE)端,而TPS2375则是IEEE 802.3af用电设备(PD)控制器,用于线缆的下行端.上述控制器不仅简化了PoE设计,而且还使之更为可靠,并符合标准.     

一种以太网介质访问控制器芯片的设计与实现

完成了10/100(Mb/s)以太网介质访问控制器芯片的设计与实现,介绍了芯片的架构和主要模块的设计方法,给出了仿真结果.芯片采用0.25μm CMOS工艺流片,工作电压为2.5 V/3.3 V.测试表明,芯片性能完全符合IEEE802.3标准,达到了设计要求.     

电源管理

TPS23751/23752:电源控制器德州仪器推出两款整合以太网供电设备(PD)管理器与DC/DC控制器的电源管理集成电路。该TPS23751与TPS23752控制器支持宽泛负载下的高转换效率,轻负载效率高。这些IC针对符合IEEE 802.3attype 2(高功率)标准的PoE应用而设计。     

PoE控制器:适合25W～70W大功率应用的产品上市

PoE(以太网供电)是通过以太网向设备提供电源的技术,它采用于2003年6月制定的IEEE 802.3af标准.PoE系统中的供电设备(PSE)主要包括网络交换设备等,用电设备(PD)主要包括IP电话机、网络摄像机等.最近,越来越多的PoE控制器可支持的功率已超过了IEEE802.3af制定的功率标准.这是因为,要实现具有更多功能的PoE设备就需要比以往更大的功率.     

CommScope SYSTIMAX万兆以太网铜缆

IEEE802.3an标准2002年7月,IEEE通过了802.3ae标准(万兆光纤以太网标准),但该标准并不适用于企业局域网所普遍采用的铜缆连接。因此,为了满足万兆铜缆以太网的需求,IEEE于2004年3月正式通过了802.3ak(10GBase-CX4)标准,该标准允许在同轴铜缆上实现万兆以太网传输。由于传输距离限制在15米内,10GBase-CX4多被应用于机房内的机架和堆栈设备的短距离互连。为了使双绞线铜缆能够在100米的距离上实现万兆以太网,IEEE紧接着开始起草802.3an标准,预计最终在2006年完成该标准。IEEE802.3an工作组的目标是在以下介质上达到10Gbit/s的传输…     

以太网供电新标准促热网络化电源管理应用市场

日前,相关国际标准组织批准了IEEE802.3at以太网供电(POE)技术标准,使远程电源通过以太网支持的最大功率从以前IEEE802.3af标准的15.4W大幅度提升到了25W.     

TPS23751/23752：电源控制器

德州仪器推出两款整合以太网供电设备（PD）管理器与DC/DC控制器的电源管理集成电路。该TPS23751与TPS23752控制器支持宽泛负载下的高转换效率,轻负载效率高。这些IC针对符合IEEE 802.3attype 2（高功率）标准的PoE应用而设计。     

新品发布

智翔推出HR-104宽带路由器该产品支持IEEE802.310BASE-T以太网络、IEEE802.3u100BASE-TX快速以太网络以及IEEE802.3x流量控制等多种标准。HR-104路由器带有1个广域网络口和4个以太网口，内置了一个用于局域网的交换控制器，以太口都支持自动协商网络速度的功能。HR-104为访问In     

10G b/s以太网技术标准及其收发模块的研制

10Gbit/s以太网的标准(pIEEE802.3ae)是IEEE802.3委员会目前正在制定中的以太网的最新标准.随着WDM(波分复用)技术的商业化应用,电信骨干网的带宽瓶颈已经得到缓解甚至出现过剩.与此同时,城域网以及接入网的带宽急待提高. 　　……     

变压器隔离式12端口PSE控制器

Linear Technology Corporation推出隔离式12端口供电设备(PSE)控制器芯片组LTC4270/LTC4271,这两款器件为用于IEEE 802.3at(PoE+)Type 1和Type 2兼容的以太网供电(PoE)系统而设计。     

The 802.3z Gigabit Ethernet Standard

Considers standards development in the IEEE 802.3z Gigabit Ethernet Task Force, part of the IEEE 802.3 CSMA/CD Working Group. IEEE Std 802.3z-1998 was formally approved by the IEEE Standards Board on June 25th, 1998. IEEE Std 802.3z, extends the operating speed of the world's most popular local area network to 1 billion bits per second (1000 Mb/s) for interconnecting high-performance switches, routers, and servers in the backbone of local area networks. Maintaining backward compatibility with the over-100-million-node installed base of 10 Mb/s and 100 Mb/s was a key requirement     

THE NEXT GENERATION OF ETHERNET

This paper discussed the challenges facing the body that will define the next generation of Ethernet technology. This is the task facing the IEEE P802.3ba Task Force, which was recently approved by the IEEE Standards Association Standards Board to begin developing the standard that will follow 10 Gigabit Ethernet (GbE). The task force is beginning the development of the next generation of Ethernet at a time when existing networks are already being strained by current capacity requirements. Network engineers forced to deal with this issue are attempting to plan their networks to support anticipated increasing bandwidth requirements. The industry is looking to the next generation of Ethernet for relief from existing and potential future network bottlenecks that are being created as data aggregation drives bandwidth requirements to double approximately every 18 months.     

100Base-T/IEEE 802.12/packet switching

Three LAN technologies look set to satisfy the ever-increasing demand for LAN bandwidth. Two of these technologies are 100 Mb/s shared-medium LANs: 100Base-T (aka IEEE 802.3 Fast Ethernet) and IEEE 802.12 (aka 100VG-AnyLAN or 100VG). The third technology is packet switching, which is really an extension of existing LAN bridge technology, but offers excellent performance gains at very low cost. The authors describe the three technologies and provide a comparison between the two 100 Mb/s LANs. Also presented are results that compare the measured performance of 100 Mb/s shared-medium LANs with switched LANs     

3-V MSM-TIA for Gigabit Ethernet

The paper describes a 3-V monolithically integrated metal-semiconductor-metal photodetector (MSM-PD) and transimpedance amplifier (TIA) chip that is fully compliant with the Gigabit Ethernet receiver specification for the short-reach application (IEEE 802.3z 1000BASE-SX). Key typical performance specifications are -22 dBm sensitivity, 1200 MHz 3-dB bandwidth, 1300-V/W differential responsivity, and 120-mW power dissipation at 3 V. The chip is fabricated in a production 0.5-μm gate length GaAs MESFET technology and is packaged in a TO-46 header with a flat window and a ball-lens cap option     

以太无源光网络的远程测试和维护的研究

简要介绍了无源光网络的发展,着重介绍了以太无源光网络的前景和对远程测试和维护的需求,分析了IEEE 802.3ah相关标准和OAM子层的位置及目标要求,给出了EPON的远程测试和维护方案.     

基于VxWorks的CAN与千兆以太网互联设计

随着千兆网络的逐步全面积覆盖,现用的百兆网关工业设备将被淘汰。为改进现用的网关设备,文中提出了一种千兆网与现场总线的互联设计。在硬件设计中,分为CAN模块电路和千兆网模块电路两部分。AX88180和M88E1111为构成千兆网关模块的主体器件;在软件设计中,以VxWorks操作系统作为软件平台。利用Socket编程完成了网络协议和CAN总线协议的相互转化。通过测试证明,设计千兆网关的可实用性。     

弹性以太环节点设计方案

提出一种基于IEEE802.17标准和IEEE802.3标准的弹性以太环节点设计方案,以及主要模块详细的功能设计,并给出了弹性以太环节点验证系统的设计方案.该方案既有效利用了RPR的特点,又实现了在城域网络中传输以太网数据和有效降低城域网络建设成本的目的.     

以太网相关技术标准规范与标准组织简介(二)

中首先介绍电气与电子工程师学会(IEEE)组织概况，然后概括说明了IEEE关于局域网／城域网IEEE802．2标准系列、以太网集成电路标准图标，特别着重讨论了关于以太网的IEEE802．3系列标准、在SDH／WDM网络上传输以太网帧信号的相关规范和10吉比特以太网技术标准。最后指出，10吉比特以太网技术标准的开发和广泛应用将在通信领域展现出更加辉煌的明天。     

以太网相关技术标准规范与标准组织简介(一)

中首先介绍电气与电子工程9币学会(IEEE)组织概况，然后概括说明了IEEE关于局域网／城域网IEEE802．2标准系列、以太网集成电路标准图标，特别着重讨论了关于以太网的IEEE802．3系列标准、在SDH／WDM网络上传输以太网帧信号的相关规范和lO吉比特以太网技术标准。最后指出，10吉比特以太网技术标准的开发和广泛应用将在通信领域展现出更加辉煌的明天。     

A fully integrated CMOS receiver front-end for optic GigabitEthernet

A fully integrated fiber-optic receiver chip in a CMOS technology is presented. The design was done in a low-cost mixed-signal analog pure CMOS technology with 0.35-μm gate length. It incorporates every building block needed for standard fiber-optic receiver application, e.g., transimpedance amplifier, postamplifier, signal detect, and several control circuits. The chip works without any external components, such as capacitors usually needed to ensure the broadband operation down to several tens of kilohertz. Three designs were processed for typical data applications between 155 Mb/s and 1.25 Gb/s. The difference in the designs can be created by changing only one metal mask and programming some bandwidth and noise-relevant components on the chip. The results in sensitivity, dynamic range, and other behaviors are fully compliant with the relevant standards, such as SONET or IEEE 802.3 (Gigabit Ethernet) and future IEEE 1394 plastic optical fiber (POF) communication