IEEE 802.3af/at-Compliant, Powered Device Interface

Controllers with Integrated 70W High-Power MOSFET

_______________________________________________________________ Maxim Integrated Products 1

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

General Description

The MAX5982A/MAX5982B/MAX5982C provide a com-

plete interface for a powered device (PD) to comply with

(PoE) system. The MAX5982A/MAX5982B/MAX5982C

provide the PD with a detection signature, classifica-

tion signature, and an integrated isolation power switch

with inrush current control. During the inrush period,

the MAX5982A/MAX5982B/MAX5982C limit the current

to less than 182mA before switching to the higher cur-

rent limit (1700mA to 2100mA) when the isolation power

MOSFET is fully enhanced. The devices feature an input

UVLO with wide hysteresis and long deglitch time to

compensate for twisted-pair cable resistive drop and to

assure glitch-free transition during power-on/-off condi-

tions. The MAX5982A/MAX5982B/MAX5982C can with-

stand up to 100V at the input.

The MAX5982A/MAX5982B/MAX5982C support a

2-Event classification method as specified in the IEEE

802.3at standard and provide a signal to indicate when

probed by a Type 2 power sourcing equipment (PSE).

The devices detect the presence of a wall adapter power

source connection and allow a smooth switchover from

the PoE power source to the wall power adapter.

The MAX5982A/MAX5982B/MAX5982C also provide a

power-good (PG) signal, two-step current limit and fold-

back, overtemperature protection, and di/dt limit. A sleep

mode feature in the MAX5982A/MAX5982B provides low

power consumption while supporting Maintain Power

Signature (MPS). An ultra-low-power sleep mode feature

in the MAX5982A/MAX5982B further reduces power

consumption while still supporting MPS. The MAX5982A/

MAX5982B also feature an LED driver that is automati-

cally activated during sleep mode.

The MAX5982A/MAX5982B/MAX5982C are available in

a 16-pin, 5mm x 5mm, TQFN power package. These

devices are rated over the -40NC to +85NC extended

temperature range.

Features

S

Sleep Mode and Ultra-Low-Power Sleep

(MAX5982A/MAX5982B)

S

IEEE 802.3af/at Compliant

S

2-Event Classification or an External Wall Adapter

Indicator Output

S

Simplified Wall Adapter Interface

S

PoE Classification 0–5

S

100V Input Absolute Maximum Rating

S

Inrush Current Limit of 182mA Maximum

S

Current Limit During Normal Operation Between

1700mA and 2100mA

S

Current Limit and Foldback

S

Legacy UVLO at 36V

S

LED Driver with Programmable LED Current

(MAX5982A/MAX5982B)

S

Overtemperature Protection

S

Thermally Enhanced, 5mm x 5mm, 16-Pin TQFN

Applications

IEEE 802.3af/at Powered Devices

IP Phones, Wireless Access Nodes, IP Security

Cameras

WiMAXK Base Stations

19-5960; Rev 0; 6/11

WiMAX is a trademark of WiMAX Forum.

IEEE is a registered service mark of the Institute of Electrical

and Electronics Engineers, Inc.

Ordering Information appears at end of data sheet.