M1

GATE

CS

CTL

CLS

DEN

RT

T2P

Type 2 PSE

Indicator

TLV 431

6/25/12

PAD

SRD

M2

APD

T1

SRT

OPTO2

OPTO2

OPTO1

OPTO1

OPTO3

OPTO3

TPS23751

TPS23752

www.ti.com

SLVSB97 – JULY 2012

IEEE 802.3at PoE Interface with Wide Range High Efficiency DC/DC Controller

Check for Samples: TPS23751 , TPS23752

1

FEATURES

DESCRIPTION

The TPS23751 is a 16-pin integrated circuit that

2

•

IEEE 802.3at Classification with Status Flag

combines a Power-over-Ethernet (PoE) powered

•

High Efficiency Solutions Over Wide Load

device (PD) interface and a current-mode DC/DC

Range

controller

optimized

specifically

for

applications

•

Powers up to 25.5 W PDs

requiring high efficiency over a wide load range.

•

Robust 100 V, 0.5

Ω Hotswap MOSFET

The PoE interface implements type-2 hardware

classification per IEEE 802.3at. It also includes an

•

Synchronous Rectifier Disable Signal

auxiliary power detect (APD) input and a disable

•

PowerPad™ TSSOP Packages

function (DEN). A 0.5

Ω, 100 V pass MOSFET

•

Complete PoE Interface Plus DC/DC Controller

minimizes heat dissipation and maximizes power

•

Adapter ORing Support

utilization.

•

Programmable Frequency

The DC/DC controller features internal soft-start, a

bootstrap

startup

current

source,

current-mode

•

TPS23752 Supports Ultra-Low Power Sleep

control

with

slope

compensation,

blanking,

and

Modes

current limiting. Efficiency is enhanced at light loads

•

–40°C to 125°C Junction Temperature Range

by disabling synchronous rectification and entering

variable frequency operation (VFO).

APPLICATIONS

The TPS23752 is a 20-pin extended version of the

•

IEEE 802.3at-Compliant Devices

TPS23751 with the addition of a sleep mode feature.

•

Video and VoIP Telephones

Sleep mode disables the converter to minimize power

consumption while still generating the Maintain Power

•

Multiband Access Points

Signature (MPS) required by IEEE802.3at.

•

Security Cameras

•

Pico-Base Stations

Figure 1. Typical Application Circuit

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

PowerPad is a trademark of Texas Instruments.

PRODUCT PREVIEW information concerns products in the

Copyright © 2012, Texas Instruments Incorporated

formative or design phase of development. Characteristic data and

other specifications are design goals. Texas Instruments reserves

the right to change or discontinue these products without notice.