TPS23751_14 Datasheet, PDF (1/47 Pages) Texas Instruments – IEEE 802.3at PoE Interface with Wide Range High Efficiency DC-DC Controller

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TPS23751
TPS23752
SLVSB97A – JULY 2012 – REVISED AUGUST 2012
IEEE 802.3at PoE Interface with Wide Range High Efficiency DC-DC Controller
Check for Samples: TPS23751 , TPS23752
FEATURES
1
•2 IEEE 802.3at Classification with Status Flag
• High Efficiency Solutions over Wide Load
Range
• Powers up to 25.5 W PDs
• Robust 100 V, 0.5 Ω Hotswap MOSFET
• Synchronous Rectifier Disable Signal
• PowerPAD™ TSSOP Packages
• Complete PoE Interface Plus DC-DC Controller
• Adapter ORing Support
• Programmable Frequency
• TPS23752 Supports Ultra-Low Power Sleep
Modes
• –40°C to 125°C Junction Temperature Range
APPLICATIONS
• IEEE 802.3at-Compliant Devices
• Video and VoIP Telephones
• Multiband Access Points
• Security Cameras
• Pico-Base Stations
DESCRIPTION
The TPS23751 is a 16-pin integrated circuit that
combines a Power-over-Ethernet (PoE) powered
device (PD) interface and a current-mode DC-DC
controller optimized specifically for applications
requiring high efficiency over a wide load range.
The PoE interface implements type-2 hardware
classification per IEEE 802.3at. It also includes an
auxiliary power detect (APD) input and a disable
function (DEN). A 0.5 Ω, 100 V pass MOSFET
minimizes heat dissipation and maximizes power
utilization.
The DC-DC controller features internal soft-start, a
bootstrap startup current source, current-mode
control with slope compensation, blanking, and
current limiting. Efficiency is enhanced at light loads
by disabling synchronous rectification and entering
variable frequency operation (VFO).
The TPS23752 is a 20-pin extended version of the
TPS23751 with the addition of a Sleep Mode feature.
Sleep Mode disables the converter to minimize power
consumption while still generating the Maintain Power
Signature (MPS) required by IEEE802.3at.
DA
VB
RAPD1
DEN
CLS
PAD
VSS
APD
CTL
RT
T1
OPTO3
T2P
VC
VB
RT2P
SRT
GATE
CS
SRD
RVC
M1
OPTO2
CIN
DVC1
DOUT
M2
OPTO3
ROB
VOUT
OPTO1
CIZ
OPTO1
CIO
OPTO2
TLV431
Figure 1. Typical Application Circuit
VOUT
Type 2 PSE
Indicator
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.
PowerPAD is a trademark of Texas Instruments.
2
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 © 2012, Texas Instruments Incorporated