NG Ethernet Forum

Nationals LM5070 is an IC with Integrated Power Over Ethernet PD (= powered device) Interface and PWM Controller. A detailed description can be found at http://www.national.com/pf/LM/LM5070.html.
It converts a supply of up to 80V / 400mA into a programmable output voltage using a current mode pulse width modulator dc-dc converter.
An application node for using the LM5070 together with Nationals Gigabit Ethernet PHY "DP83865" is found at http://www.national.com/an/AN/AN-1408.pdf.