1FEATURES

2• Compatible with 12V AC Adapters

• Fully Compliant 802.3af Power Interface Port

• 80V, 1Ω, 400 mA Internal MOSFET

• Detection Resistor Disconnect Function

• Programmable Classification Current

• Programmable Under-voltage Lockout with

Programmable Hysteresis

• Thermal Shutdown Protection

• Auxiliary Power Enable Pin

• 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)

PACKAGES

• TSSOP-16

DESCRIPTION

The LM5071 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 LM5071 is specifically designed for the PD

that must accept power from auxiliary sources

such as AC adapters. The auxiliary power interface

of the LM5071 activates the PWM controller when the

ac adapter is connected to power the PD when PoE

network power is unavailable. The LM5071 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.