SI3400-GM Datasheet, PDF(1/20 Page) List of Unclassifed Manufacturers – FULLY-INTEGRATED 802.3-COMPLIANT PD INTERFACE AND SWITCHING REGULATOR

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SI3400-GM Datasheet, PDF (1/20 Pages) List of Unclassifed Manufacturers – FULLY-INTEGRATED 802.3-COMPLIANT PD INTERFACE AND SWITCHING REGULATOR

Si3400

Si3401

FULLY-INTEGRATED 802.3-COMPLIANT PD INTERFACE

AND SWITCHING REGULATOR

Features

IEEE 802.3 standard-compliant

solution, including pre-standard

(legacy) PoE support

Highly-integrated IC enables

compact solution footprints

Minimal external components

Integrated diode bridges and

transient surge suppressor

Integrated switching regulator

controller with on-chip power

FET

Integrated dual current-limited

hotswap switch

Applications

Support non-isolated and

isolated switching topologies

Comprehensive protection

circuitry

Transient overvoltage

protection

Undervoltage lockout

Early power-loss indicator

Thermal shutdown protection

Foldback current limiting

Programmable classification

circuit

Low-profile 5 x 5 mm 20-pin QFN

Pb-Free and RoHS-compliant

Ordering Information:

See Ordering Guide on page

page 17.

Pin Assignments

5 x 5 mm QFN

(Top View)

Voice over IP telephones and

adapters

Wireless access points

Security cameras

Description

Point-of-sale terminals

Internet appliances

Network devices

High power applications (Si3401)

The Si3400 and Si3401 integrate all power management and control

functions required in a Power-over-Ethernet (PoE) powered device (PD)

application. The Si3400 and Si3401 convert the high voltage supplied over

the 10/100/1000BASE-T Ethernet connection into a regulated, low-voltage

output supply. The optimized architectures of the Si3400 and Si3401

minimize the solution footprint, reduce external BOM cost, and enable the

use of low-cost external components while maintaining high performance.

The Si3400 and Si3401 integrate the required diode bridges and transient

surge suppressors, thus enabling direct connection of ICs to the Ethernet

RJ-45 connector. The switching power FET and all associated functions are

also integrated. The integrated switching regulator supports isolated

(flyback) and non-isolated (buck) converter topologies. The Si3400 and

Si3401 support IEEE STDâ¢ 802.3-2005 (future instances are referred to as

802.3) compliant solutions as well as pre-standard products, all in a single

IC. Standard external resistors connected to the Si3400 and Si3401 provide

the proper 802.3 signatures for the detection function and programming of

the classification mode. Startup circuits ensure well-controlled initial

operation of both the hotswap switch and the voltage regulator. The Si3400

and Si3401 are available in low-profile, 20-pin, 5 x 5 mm QFN packages.

While the Si3400 is designed for applications up to 10 W, the Si3401 is

optimized for higher power applications (up to approximately 15 W). See

also âAN313: Using the Si3400/01 in High Power Applicationsâ for more

information.

20 19 18 17 16 15

EROUT 1

SSFT 2

VDD 3

ISOSSFT2 4

VNEG

(PAD)

14 CT1

13 CT2

12 VPOSF

11 SP1

5 6 7 8 9 10

Notes:

1. Pin VSSA added on revisions CZ

and higher.

2. Pin ISOSSFT added on revisions

CZ and higher. Function available

on revision E silicon. For Rev CZ,

or to disable this feature on

Revision E, tie this pin to VDD.

Rev. 0.9 8/07

Si3400/Si3401

This information applies to a product under development. Its characteristics and specifications are subject to change without notice.

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