TPS23753 Datasheet, PDF (1/27 Pages) Texas Instruments – IEEE 802.3-2005 PoE INTERFACE AND ISOLATED CONVERTER CONTROLLER

TPS23753
www.ti.com.............................................................................................................................................................. SLVS853A – JUNE 2008 – REVISED JUNE 2008
IEEE 802.3-2005 PoE INTERFACE AND ISOLATED CONVERTER CONTROLLER
FEATURES
1
• Optimized for Isolated Converters
• Complete PoE Interface
• Adapter ORing Support
• 12 V Adapter Support
• Programmable Frequency with Synch.
• Robust 100 V, 0.7 Ω Hotswap MOSFET
• Small TSSOP 14 Package
• 15 kV / 8 kV System Level ESD Capable
• –40°C to 125°C Junction Temperature Range
• Design Procedure Application Note - SLVA305
• Adapter ORing Application Note - SLVA306
APPLICATIONS
• IEEE 802.3-2005 Compliant Powered Devices
• VoIP Telephones
• Access Points
• Security Cameras
DESCRIPTION
The TPS23753 is a combined Power over Ethernet
(PoE) powered device (PD) interface and
current-mode dc/dc controller optimized specifically
for isolated converter designs. The PoE
implementation supports the IEEE 802.3-2005
(previously 802.3af) standard, 12.95 W (13 W) PD.
The TPS23753 supports a number of input-voltage
ORing options including highest voltage, external
adapter preference, and PoE preference.
The PoE interface features an external detection
signature pin that can also be used to disable the
internal hotswap MOSFET. This allows the PoE
function to be turned off. Classification can be
programmed to any of the defined types with a single
resistor.
The dc/dc controller features a bootstrap startup
mechanism with an internal, switched current source.
This provides the advantages of cycling overload fault
protection without the constant power loss of a pull up
resistor.
The programmable oscillator may be synchronized to
a higher-frequency external timing reference.
BR1
BR2
*
D_A
Adapter
R _APD1
DEN
CLS
V _SS
APD
FRS
V_C
V_B
GATE
CS
CTL
*
D _VC
M1
C _IN
R _VC
V_B
R _CTL
* Adapter interface and R _BLNK are Optional
Figure 1. Basic TPS23753 Implementation
T1
D_S
C _OUT
V _OUT
C _CTL
R _OB
C _IZ
C_{IO TLV431}
R _FBU
R _FBL
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated