Si3400
Si3401
F
U L L Y
-I
N T E G R A T E D
8 0 2 . 3 - C
O M P L I A N T
P D I
N T E R F A C E
AND
S
WITCHING
R
EGULATOR
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
Ordering Information:
See Ordering Guide on page
page 17.
Pin Assignments
5 x 5 mm QFN
(Top View)
VPOSS
16
Applications
Voice over IP telephones and
adapters
Wireless access points
Security cameras
Point-of-sale terminals
Internet appliances
Network devices
High power applications (Si3401)
20
19
18
17
15
EROUT
SSFT
VDD
ISOSSFT
2
1
2
3
4
VSSA
VSS2
VSS1
SWO
FB
1
14
CT1
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.
Rev. 0.9 8/07
Copyright © 2007 by Silicon Laboratories
VNEG
(PAD)
13
CT2
12
11
VPOSF
SP1
5
6
7
8
9
10
RDET
PLOSS
RCL
VNEG
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.
HSO
Si3400/Si3401
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
SP2
Si3400/Si3401
T
A B L E
Section
OF
C
O N T E N TS
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Typical Application Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2. PD Hotswap Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3. Switching Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Rev. 0.9
3
Si3400/Si3401
1. Electrical Specifications
Table 1. Absolute Maximum Ratings (DC)
1
Type
Voltage
CT1 to CT2
SP1 to SP2
VPOS
2
HSO
VSS1 or VSS2
SWO
PLOSS to VPOS
2
RDET
RCL
SSFT to VPOS
2
EROUT to VSS1, VSS2, or VSSA
FB to VPOS
RIMAX to VSS1, VSS2, or VSSA
VSS1 to VSS2 or VSSA
VDD to VSS1, VSS2, or VSSA
Current
RCL
RDET
CT1, CT2, SP1, SP2
VPOS
2
HSO
PLOSS
VDD
SWO
VSS1, VSS2, or VSSA
Ambient
Temperature
Storage
Operating
Description
Rating
–60 to 60
–60 to 60
–0.3 to 60
–0.3 to 60
–0.3 to 60
–0.3 to 60
–60 to 0.3
–0.3 to 60
–0.3 to 5
–5 to 0.3
–0.3 to VDD+0.3
–5 to 0.3
–0.3 to VDD+0.3
–0.3 to 0.3
–0.3 to 5
0 to 100
0 to 1
–400 to 400
–400 to 400
0 to 400
–0.5 to 5
0 to 2
0 to 400
–400 to 0
–65 to 150
–40 to 85
°C
mA
V
Unit
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.
4
Rev. 0.9
Si3400/Si3401
Table 2. Absolute Maximum Ratings (Transient)
1
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
Voltage
CT1 to CT2
SP1 to SP2
VPOS
2
HSO
Description
Rating
–82 to 82
–82 to 82
–0.7 to 80
–0.7 to 80
–0.7 to 80
–0.7 to 80
–80 to 0.7
–0.7 to 80
–5 to 5
–5 to 5
–2 to 2
Unit
VSS1, VSS2, or VSSA
SWO
PLOSS to VPOS
2
RDET
Current
ESD
3
CT1, CT2, SP1, SP2
VPOS
2
V
A
kV
HBM, all pins
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.
3.
For more information regarding system-level ESD tolerance, refer to “AN315: Robust Electrical Surge Immunity for PoE
PDs through Integrated Protection”.
Table 3. Recommended Operating Conditions
Description
|CT1 – CT2| or |SP1 – SP2|
Ambient Operating Temperature
Symbol
VPORT
TA
Min
2.8
–40
Typ
—
25
Max
57
85
Units
V
°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.
Rev. 0.9
5
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