Following the ratification of the IEEE 802.3af standard for PoE (power-over-Ethernet) in recent weeks, PowerDsine has introduced a highly integrated IC to manage PoE distribution in equipment such as multiport hubs. The chip is built in Motorola's (www.motorola.com) SmartMOS8 technology, allowing power switches to be integrated on to the same die as the control logic; the PD64012 is therefore a complete PoE manager for 12 channels, to which you need add only three passive components per channel. For a typical 48-port switch design, the total component count to add PoE is less than 200, PowerDsine says. The chip includes functions such as detection of PoE-service demand, real-time port protection (current-limiting into a fault condition), and ac or dc disconnection. Devices identify themselves according to categories, setting how much power you can expect them to use, and the device sets protection levels accordingly.

You can cascade the chips for designs of more than one port and set a power budget for the complete configuration. Power is typically provisioned statistically, on the basis that not all ports will together be drawing maximum power. One chip in a cluster can act as controller, with the rest of the chips slaved to it, or all chips can cede control to a host-system controller. This provision is necessary if your design needs to detect and provision power to equipment designed before the standard was ratified; otherwise, the embedded standard-compliant software is sufficient. Interchip communication is by I²C bus.

PowerDsine's chief executive officer Igal Rotem anticipates PoE's becoming a dominant standard for the provision of power to both small LAN-connected items of equipment and to small-demand items that may not be using the Ethernet connection. Such equipment would use the PoE connection simply as a matter of convenience. Rotem expects the first design for a mobile-phone-battery charger with an RJ45 plug to emerge very soon. The PD64012 will cost $18 (1000).

PowerDsine, +44 208 622 3107, www.powerdsine.com.