TPS23750 Datasheet, PDF (1/38 Pages) Texas Instruments – INTEGRATED 100-V IEEE 802.3af PD AND DC/DC CONTROLLER

www.ti.com
TPS23750
TPS23770
SLVS590A – JULY 2005 – REVISED AUGUST 2005
INTEGRATED 100-V IEEE 802.3af PD AND DC/DC CONTROLLER
FEATURES
• Complete 802.3af PoE Interface
– Features derived from the TPS2375
– 100 V, 0.6 Ω Internal Pass MOSFET
– Standard and Legacy UVLO Choices
– Fixed 140 mA Inrush Limit
• Primary Side DC/DC Converter Control
– Minimum External Component Count
– Current Mode Control
– Isolated and Non-Isolated Topologies
– Programmable Operating Frequency
– Current Sense Leading-edge Blanking
– 50% Duty Cycle Limiting
– Voltage Output Error Amplifier
• Internal PoE and Converter Sequencing
• Industry-Standard 20 Lead Package
• Industrial Temperature Range: –40°C to 85°C
APPLICATIONS
• All PoE PD Devices Including:
– Wireless Access Points
– VoIP Phones
– Security Cameras
V_DD
DESCRIPTION
The TPS23750 integrates the functionality of the
TPS2375 with a primary-side dc/dc PWM controller.
The designer can create a front-end solution for
PoE-PD applications with minimum external
components. The TPS23770 is identical to the
TPS23750 with the exception of the undervoltage
lockout turn-on voltage, which is compatible with
legacy systems.
The PoE front end has all the necessary IEEE
802.3af functions including detection, classification,
undervoltage lockout and inrush control. The PoE
input switch is integrated within the TPS23750.
The dc/dc controller section is designed to support
flyback, forward, and nonsynchronous low-side switch
buck topologies.
The external switching MOSFET and current sense
resistor provide flexibility in topology, power level, and
current limit. The full-featured dc/dc controller in-
cludes programmable soft start, hiccup type fault
limiting, 50% maximum duty cycle, programmable
constant switching frequency, and a true volt-
age-output error amplifier. Additional protection fea-
tures provide for robust designs.
V_BIAS
DET
CLASS
V_SS
COMP
BL
MODE
V_BIAS
FREQ
TMR
AUX
GATE
RSP
V_BIAS
Low Voltage
Isolated
Output
TLV431
Figure 1. Typical Application
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.
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 © 2005, Texas Instruments Incorporated