NOTICE: This site has been designed to be compliant with the latest web standards. Please upgrade your web browser to enjoy this website at its best.
Microsemi, IRVINE, Ca. 6th August 2008
Microsemi Corporation announced today its support for the revised maximum inductance specification drafted for the IEEE802.3at high power over Ethernet standards, citing that it will enable lower cost solutions from network switch manufacturers.
Microsemi, which supplies Power over Ethernet chipsets for network switches, now expects the cost of hardware to build a PoEPlus switch delivering 30 watts per port to become the same or lower than that of conventional low power switches, excluding the power supply.
The revised IEEE802.3at-draft3.1 reduces the maximum inductance requirements for pulse transformers from 350 Micro Henry to 120 Micro Henry, the result of advances in PHY technology since passage of the current low power IEEE802.3af standard. The draft standard, which almost doubles the power available over Ethernet cables, can support new applications including IEEE802.11n Wireless LAN access points, IEEE802.16 WiMAX subscriber stations and base stations, and fiber to the home optical network terminators.
Without this change, some switch manufacturers -- facing the cost of bigger PoEPlus magnetics -- would likely opt to build switches with only a few high power ports. Now they can allow all ports to support PoEPlus, using the power supply size to determine how many ports get high power capability.
"As Microsemi anticipates ultimate approval of the IEEE802.3at draft, we've developed a compliant line of multiport High Power over Ethernet chipsets supporting 4-port, 8-port, and 12-port switches and midspans for the enterprise market, as well as a single-port chipset designed for residential applications," said Steve Litchfield, Executive Vice President and President of Microsemi's Analog Mixed Signal Group.
The PD69012 -- designed for the enterprise and SME switch markets -- enables building switches with advanced levels of integration to provide low power loss and high power capability with minimum-sized power supplies. The resulting switch solutions cost less and reduce system power consumption. The PD69012 supports 2-event classification. The PD64004AH targets SoHo and SME applications, as well as enterprise switches with four high power ports. It supports the 600mA maximum ongoing current requirement of the IEEE802.3at draft.
The PD64001, sized for residential applications, allows companies to build switches and midspans with one PoE port. Support for 2-event hardware classification allows fast powering of end devices. Microsemi's patented Dynamic Power Management technology, unique in the industry, allows manufacturers to build PoE switches with virtually any sized power supply, determined by the number of high power end devices to be supported. There is no need for pre-allocation of power or fixed denomination of ports.
An exclusive Emergency Power Management feature allows users to support up to 16 different power supplies in a switch, allowing IT managers to extend a switch having a small internal power budget, simply by adding power supplies in a modular fashion as more high power devices need to receive power from the switch. Microsemi's Emergency Power Management capability disconnects low priority ports in case of power supply failures in a switch having 2 to 16 power supplies. Dynamic Power Management and Emergency Power Management are supported by all Microsemi multiport chipsets compliant with the IEEE802.3at-draft3.1.
About Power over Ethernet Technology
Power over Ethernet (PoE) is a technology for wired Ethernet, the most widely installed local area network technology in use today. PoE allows the electrical power necessary for the operation of each end-device to be carried by data cables, rather than by separate power cords. It minimizes the number of wires used to install the network, resulting in lower cost, less downtime, easier maintenance and greater installation flexibility. The technology was pioneered by PowerDsine, a founding member of the IEEE 802.3af Task Force. The company was acquired by Microsemi Corporation in January 2007 and is now part of Microsemi's Analog Mixed Signal Group. Microsemi is a member of the IEEE802.3at Task Force.