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.