SI3402 Datasheet, PDF (1/22 Pages) List of Unclassifed Manufacturers – FULLY-INTEGRATED 802.3-COMPLIANT POE PD INTERFACE FULLY-INTEGRATED 802.3-COMPLIANT POE PD INTERFACE

Si3402
FULLY-INTEGRATED 802.3-COMPLIANT POE PD INTERFACE
AND LOW-EMI 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
 Programmable classification
circuit
 Incorporates switcher EMI-
reduction techniques.
 Supports non-isolated and
isolated switching topologies
 Comprehensive protection
circuitry
Transient overvoltage
protection
Undervoltage lockout
Early power-loss indicator
Thermal shutdown protection
Foldback current limiting
 Low-profile 5 x 5 mm 20-pin QFN
 RoHS-compliant
Applications
 Voice over IP telephones and
adapters
 Wireless access points
 Security cameras
Description
 Point-of-sale terminals
 Internet appliances
 Network devices
 High power applications
The Si3402 integrates all power management and control functions required
in a Power-over-Ethernet (PoE) powered device (PD) application. The
Si3402 converts the high voltage supplied over the 10/100/1000BASE-T
Ethernet connection into a regulated, low-voltage output supply. The
optimized architecture of the Si3402 minimizes the solution footprint,
reduces external BOM cost, and enables the use of low-cost external
components while maintaining high performance. The Si3402 integrates the
required diode bridges and transient surge suppressor, thus enabling direct
connection of the IC 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 Si3402 supports IEEE Std 802.3™ 2008 including
the IEEE Std 802.3at-2009 amendment for the case of single-event
classification. Standard external resistors connected to the Si3402 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 Si3402
is available in a low-profile, 20-pin, 5 x 5 mm QFN package. While the
Si3402 is designed for applications up to 10 W, it can be used for higher
power applications (up to approximately 15 W). See also “AN313: Using the
Si3402 in High Power Applications” for more information.
Ordering Information:
See page 18.
Pin Assignments
5 x 5 mm QFN
(Top View)
20 19 18 17 16 15
EROUT 1
SSFT 2
VDD 3
ISOSSFT 4
VNEG
(PAD)
14 CT1
13 CT2
12 VPOSF
11 SP1
5 6 7 8 9 10
Rev. 1.31 8/13
Copyright © 2013 by Silicon Laboratories
Si3402