Silicon Laboratories Si3400, Si3401 Technical data

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

 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

Applications

 Voice over IP telephones and

adapters

 Wireless access points  Security cameras

 Point-of-sale terminals  Internet appliances  Network devices  High power applications (Si3401)

Description

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 STD™ 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 “AN313: Using the Si3400/01 in High Power Applications” for more information.

Ordering Information:

See Ordering Guide on page

page 18.

Pin Assignments

5x5mm QFN

(Top View)

VPOSS

VSS1

SWO

VSS2

EROUT

SSFT

VDD

ISOSSFT

VNEG (PAD)

5678

HSO

RDET

PLOSS

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.

VSSA

151620 19 18 17

SP2

RCL

VNEG

CT1

CT2

VPOSF

SP1

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

Si3400/Si3401

Functional Block Diagram

CT1

CT2

SP1

SP2

VPOSF

VNEG

VPOSS

Rectification

Protection

RDET RCL

Detection

Classification

Hotswap

Switch

Current limit

HSO

SSFT ISOSSFT

PLOSS

VDD

Hotswap

Control

Common

Bias

VSSA

Switcher

Control

Switching

FET

VSS1

EROUT

SWO

VSS2

2 Preliminary Rev. 0.91

Si3400/Si3401

TABLE OF CONTENTS

Section Page

1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

2. Typical Application Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

3. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

3.2. PD Hotswap Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

3.3. Switching Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

4. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

5. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

6. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Preliminary Rev. 0.91 3

Si3400/Si3401

1. Electrical Specifications

Table 1. Recommended Operating Conditions

Description Symbol Min Typ Max Units

|CT1 – CT2| or |SP1 – SP2| VPORT 2.8 — 57 V

Ambient Operating Temperature TA –40 25 85 °C

Note: Unless otherwise noted, all voltages referenced to VNEG. All minimum and maximum specifications are guaranteed

and apply across the recommended operating conditions. Typical values apply at nominal supply voltage and ambient temperature unless otherwise noted.

Table 2. Absolute Maximum Ratings (DC)

Type Description Rating Unit

Voltage CT1 to CT2 –60 to 60

SP1 to SP2 –60 to 60

VPOS

HSO –0.3 to 60

VSS1 or VSS2 –0.3 to 60

SWO –0.3 to 60

PLOSS

RDET –0.3 to 60

RCL –0.3 to 5

SSFT to VPOS

EROUT to VSS1, VSS2, or VSSA –0.3 to VDD+0.3

FB to VPOS –5 to 0.3

RIMAX to VSS1, VSS2, or VSSA –0.3 to VDD+0.3

VSS1 to VSS2 or VSSA –0.3 to 0.3

VDD to VSS1, VSS2, or VSSA –0.3 to 5

Notes:

1. Unless otherwise noted, all voltages referenced to VNEG. Permanent device damage may occur if the maximum

ratings are exceeded. Functional operation should be restricted to those conditions specified in the operational sections

to VPOS

–0.3 to 60

–60 to 0.3

–5 to 0.3

4 Preliminary Rev. 0.91

Table 2. Absolute Maximum Ratings (DC)1 (Continued)

Type Description Rating Unit

Current RCL 0 to 100

RDET 0 to 1

CT1, CT2, SP1, SP2 –400 to 400

VPOS

HSO 0 to 400

PLOSS

VDD 0 to 2

SWO 0 to 400

VSS1, VSS2, or VSSA –400 to 0

Si3400/Si3401

–400 to 400

–0.5 to 5

Ambient

Temperature

Notes:

1. Unless otherwise noted, all voltages referenced to VNEG. Permanent device damage may occur if the maximum

ratings are exceeded. Functional operation should be restricted to those conditions specified in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended periods may adversely affect device reliability.

2. VPOS is equal to VPOSF and VPOSS tied together for test condition purposes.

Storage –65 to 150

Operating –40 to 85

°C

Preliminary Rev. 0.91 5

Si3400/Si3401

Table 3. Absolute Maximum Ratings (Transient)

Transient surge defined in IEC60060 as a 1000 V impulse of either polarity applied across CT1–CT2 or SP1–SP2. The shape of the impulse shall have a 300 ns full rise time and a 50 µs half fall time, with 201 Ω source impedance.

Type Description Rating Unit

Voltage CT1 to CT2 –82 to 82

SP1 to SP2 –82 to 82

VPOS

–0.7 to 80

HSO –0.7 to 80

VSS1, VSS2, or VSSA –0.7 to 80

SWO –0.7 to 80

PLOSS

to VPOS

–80 to 0.7

RDET –0.7 to 80

Current CT1, CT2, SP1, SP2 –5 to 5

VPOS

Notes:

1. Unless otherwise noted, all voltages referenced to VNEG. Permanent device damage may occur if the maximum

2. VPOS is equal to VPOSF and VPOSS tied together for test condition purposes.

–5 to 5

Table 4. Surge Immunity Ratings

1,2,3

Type Description Rating Unit

CDE

Cable discharge event tolerance –3.5 to 3.5 kV

ESD (System-Level) Air discharge (IEC 61000-4-2) –16.5 to 16.5 kV

Contact discharge (IEC 61000-4-2) –8 to 8 kV

ESD (CDM) JEDEC (JESD22-C101C) –1 to 1 kV

ESD (HBM) JEDEC (JESD22-A114E) –500 to 500 V

ESD (MM) JEDEC (JESD22-A115A) –100 to 100 V

Telephony Voltage

IEEE 802.3, Clause 33.5.6 175 Vp

Compatibility

Notes:

1. Permanent device damage may occur if the maximum ratings are exceeded. Functional operation should be restricted

to those conditions specified in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended periods may adversely affect device reliability.

2. For more information regarding system-level surge tolerance, refer to “AN315: Robust Electrical Surge Immunity for

PoE PDs through Integrated Protection”.

3. Designs must be compliant with the PCB layout and external component recommendations outlined in the Si3400/01

EVB User’s Guides and AN296.

4. J. Deatherage and D. Jones, “Multiple Factors Trigger Cable Discharge Events in Ethernet LANs,” Electronic Design

Dec. 4, 2000.

6 Preliminary Rev. 0.91

+ 14 hidden pages

Silicon Laboratories Si3400, Si3401 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual

Features

Applications

Description

Functional Block Diagram

1. Electrical Specifications

Table 1. Recommended Operating Conditions