TPS23851 Datasheet, PDF (1/62 Pages) Texas Instruments – Quad IEEE 802.3at Power-Over-Ethernet PSE Controller

TPS23851
www.ti.com
SLUSAB3 – SEPTEMBER 2010
Quad IEEE 802.3at Power-Over-Ethernet PSE Controller
Check for Samples: TPS23851
FEATURES
1
•2 INDUSTRY STANDARD PSE
– Fully IEEE Std 802.3at-2009 Compliant
– Four Independent PSE Ports
– PD Detection and Classification
– Current Limit Output Protection with
Foldback for Reduced Cost FET
– AC and DC Disconnect Detection
– I²C™ Communication
– 4 Bit Address for 64-Port Systems
– Flexible Operation Modes
– Automatic
– Semi Automatic
– Processor Controlled
– Pin Compatible with LTC4259A &
MAX5952/MAX5945/MAX5935
• ENHANCED FEATURES
– Never Fooled 4-Point Detection
– Onboard Precision 110-Hz AC Disconnect
Sine Wave Oscillator
– I²C Watchdog for Failsafe Operation
– Individual and Multiplexed Port Shutdown
Modes
– Per Port A/D Converters
– 14-Bit Resolution for Precision
Measurements
– Real-time Voltage Monitoring
– Real-time Current Monitoring
– Inherent Filtering
– Extended -20°C to 125°C Temperature
Operation
– 802.3at Type 2 Mode
– High-Power Mode
– Classification through Link Layer
Discovery Protocol (LLDP)
– Available in 36-lead SSOP Package
APPLICATIONS
• Ethernet Switches and Routers
DESCRIPTION
The TPS23851 is a quad-power controller engineered
to insert power onto Ethernet cable according to IEEE
Std 802.3at-2009 (or 802.3at) for Power Sourcing
Equipment (PSE). The PSE controller can detect
Powered devices (PDs) that have a valid signature,
determine the power requirements of the devices
according to the classification, and apply power to the
devices, limited per 802.3at. Based on an industry
standard register set, the PSE controller is software
compatible with other PSE controllers for basic
functionality
Beyond the industry standard operation, the
TPS23851 operates with enhanced features. Port
current trip point can be set to all classification
thresholds of IEEE Std 802.3-2005 (or 802.3af) and
can be programmed up to more than 720 mA when
used with a LLDP classification stack, complying with
802.3at. The TPS23851 supports AC and DC
disconnection with a precision on-chip, 110-Hz
oscillator for AC waveform generation. The PSE also
contains four 14-bit A/D converters that constantly
monitor voltage and current on each port. This
information is available on the I²C bus for power
management. The unique converter integrating
topology used in the TPS23851 provides inherent
filtering for a robust solution.
Typical Application
3.3 V
16 15 21
VDD DGND AGND
4 SCL
DET
1 kW ^{0.47 mF}
0.1mF
100 V
PORT
5 SDAO
TPS23851
6 SDAI
OUT
10 kW
3 INT
1 RESET
VEE
28
GAT
SEN
0.5 W
-48 V
Note: Only one port shown.
UDG-10111
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.
I²C is a trademark of Royal Philips Electronics.
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 © 2010, Texas Instruments Incorporated