RJ45

Connector

TX+ (1)

TX- (2)

RX+ (3)

RX- (6)

(4)

(7)

(5)

(8)

To PHY

To PHY

Hot Plug Controller

In-rush and Fault

Current Limiting

DC-DC

Converter

Controller

Current Mode

IEEE 802.3af

Interface

UVLO

Signature Detection

Classification

LM5070

VDC

LM5070

www.ti.com

SNVS308G – OCTOBER 2004 – REVISED APRIL 2013

LM5070 Integrated Power Over Ethernet PD Interface and PWM Controller

Check for Samples: LM5070

1

FEATURES

DESCRIPTION

The LM5070 power interface port and pulse width

2

•

Fully Compliant 802.3af Power Interface Port

modulation (PWM) controller provides a complete

•

80V, 1

Ω, 400 mA Internal MOSFET

integrated solution for Powered Devices (PD) that

•

Programmable Inrush Current Limit

connect into Power over Ethernet (PoE) systems. The

LM5070 integrates an 80V, 400mA line connection

•

Detection Resistor Disconnect Function

switch and associated control for a fully IEEE 802.3af

•

Programmable Classification Current

compliant interface with a full featured current mode

•

Programmable Under-voltage Lockout with

pulse width modulator dc-dc converter. All power

Programmable Hysteresis

sequencing

requirements

between

the

controller

interface and switch mode power supply (SMPS) are

•

Thermal Shutdown Protection

integrated into the IC. Two options are available

•

Current Mode Pulse Width Modulator

providing either an 80% maximum duty cycle limit

•

Supports Both Isolated and Non-Isolated

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

Applications

a 50% maximum duty cycle limit and no slope

compensation on the (–50 suffix) device.

•

Error Amplifier and Reference for Non-Isolated

Applications

PACKAGES

•

Programmable Oscillator Frequency

•

TSSOP-16

•

Programmable Soft-Start

•

WSON-16 (5 mm x 5 mm)

•

80% Maximum Duty Cycle Limiter, Slope

Compensation (-80 device)

•

50% Maximum Duty Cycle Limiter, No Slope

Compensation (-50 device)

•

800 mA Peak Gate Driver

Block Diagrams

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.