Preliminary Data

This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to

change without notice.

September 2007

Rev 1

1/10

1

PM8800

Integrated IEEE 802.3af compliant PoE-PD interface

and PWM controller with support of external source

Features

cables or from local auxiliary sources

MOSFET

compensation

Applications.

Applications

Description

The PM8800 integrates a standard Power over

Ethernet (PoE) interface and a current mode

PWM controller to simplify the design of the

power supply sections of all Powered Devices.

The PoE interface incorporates all the functions

required by the IEEE 802.3af including detection,

classification, under-voltage lockout (UVLO) and

in-rush current limitation.

PM8800 specifically targets PD with extended

power requirement with respect to the limit

imposed by the 802.3af standard, embedding a

hot-swap MOSFET capable of sustaining twice

the current of the 802.3af standard with a pro-

grammable DC current limit

The integrated switching regulator of the PM8800

has been designed to work with power either form

the Ethernet cable connection or from an external

power source such as AC adapter.

The DC/DC section of the PM8800 features a pro-

grammable oscillator frequency, soft-start, slope

compensation and embeds a voltage output error

amplifier allowing use in both isolated and non

isolated configuration.

HTSSOP16

Table 1.

Device summary

Order codes

Max duty

Package

Packaging

PM8800A

80%

HTSSOP16

Tube

PM8800A

Tape and reel

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