National Semiconductor Introduces Single-Chip Power Over Ethernet Controller

Santa Clara, CA -- National Semiconductor Corporation introduced its latest Power over Ethernet (PoE) device, which the company claims is the industry's first single-chip PoE controller for higher-power PoE applications. The LM5072, which integrates a programmable power interface port and a pulse-width modulation (PWM) controller, allows designers to operate PoE appliances at higher power levels than standard IEEE 802.3af devices.

National designed the LM5072 with programmable current limiting that allows it to draw up to 25W from a PoE-enabled port, since many emerging PoE applications require power that exceeds the limit of the existing standard. For standard 802.3af Powered Devices (PDs), the current may be programmed to any value between 150 mA and 800 mA, or the programming resistor can be simply disconnected to switch the LM5072 to the default mode with 440 mA maximum current draw. The LM5072, which has maximum input voltage and current ratings of 100V and 800 mA, also supports applications that accept power from auxiliary sources. National is demonstrating the LM5072 in booth 8/9 at the Applied Power Electronics Conference (APEC) in Dallas.

The LM5072 joins National's LM5070, which integrates a 375 mA PoE interface circuit with a DC-DC controller; and the LM5071, a single-chip solution specifically designed for PoE devices that operate from alternative power sources. Applications for the LM5072 include VoIP phones, remote security cameras, card readers, wireless access points, computer telephony, PDs in PoE systems and 48V telecom power supply controls.

"National's LM5072 responds to the increasing market demand for complete solutions for higher-power PoE applications, as well as for devices that can be powered from auxiliary power sources," said Paul Greenland, director of strategic marketing for National Semiconductor's Power Management Group. "With the addition of the LM5072 to our family of PoE products, National can provide designers with an integrated, single-chip PD solution to their PoE design challenges, whether those applications are for 802.3af networks or for customized, higher-power PoE systems."

SOURCE: National Semiconductor