PoE Controller Fits On Single Chip

Introduced as the first single-chip power over Ethernet (PoE) controller for high-power designs, the LM5072 specifies maximum input voltage and current ratings of 100V and 800 mA, respectively, and integrates a programmable power interface port and a PWM controller. For standard 802.3af applications, current may be programmed to any value between 150 mA and 800 mA, or the programming resistor can be disconnected to switch the device to the default mode with 440 mA maximum current. In-rush current limiting defaults to 150 mA, but is programmable over the same range as the port current. Additionally, the device is available with either 50% or 80% maximum PWM duty cycle, which allows it to support a variety of dc/dc converter topologies and operation over an extended auxiliary supply-voltage range. Price is $1.85 each/1,000. NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.