FEATURES

? Fully Compliant 802.3af Power Interface Port

? 80V, 1Ω, 400 mA Internal MOSFET

? Programmable Inrush Current Limit

? Detection Resistor Disconnect Function

? Programmable Classification Current

? Programmable Under-voltage Lockout with

Programmable Hysteresis

? Thermal Shutdown Protection

? Current Mode Pulse Width Modulator

? Supports Both Isolated and Non-Isolated

Applications

? Error Amplifier and Reference for Non-Isolated

Applications

? Programmable Oscillator Frequency

? Programmable Soft-Start

? 80% Maximum Duty Cycle Limiter, Slope

Compensation (-80 device)

? 50% Maximum Duty Cycle Limiter, No Slope

Compensation (-50 device)

? 800 mA Peak Gate Driver

DESCRIPTION

The LM5070 power interface port and pulse width

modulation (PWM) controller provides a complete

integrated solution for Powered Devices (PD) that

connect into Power over Ethernet (PoE) systems. The

LM5070 integrates an 80V, 400mA line connection

switch and associated control for a fully IEEE 802.3af compliant interface with a full featured current mode

pulse width modulator dc-dc converter. All power

sequencing requirements between the controller

interface and switch mode power supply (SMPS) are

integrated into the IC. Two options are available providing either an 80% maximum duty cycle limit

with slope compensation (on the –80 suffix) device or

50% maximum duty cycle limit and no slope

compensation on the (–50 suffix) device.