LM5071_14 Datasheet, PDF (1/23 Pages) Texas Instruments – Power Over Ethernet PD Controller with Auxiliary Power Interface

LM5071
www.ti.com
SNVS409D – NOVEMBER 2005 – REVISED APRIL 2006
LM5071 Power Over Ethernet PD Controller with Auxiliary Power Interface
Check for Samples: LM5071
FEATURES
1
•2 Compatible with 12V ac adapters
• Fully Compliant 802.3af Power Interface Port
• 80V, 1Ω, 400 mA Internal MOSFET
• Detection Resistor Disconnect Function
• Programmable Classification Current
• Programmable Under-voltage Lockout with
Programmable Hysteresis
• Thermal Shutdown Protection
• Auxiliary Power Enable Pin
• Current Mode Pulse Width Modulator
• Supports both Isolated and Non-Isolated
Applications
• Error Amplifier and Reference for Non-Isolated
Applications
• Programmable Oscillator Frequency
• Programmable Soft-start
• 80% Maximum Duty Cycle Limiter, Slope
Compensation (-80 device)
• 50% Maximum Duty Cycle Limiter, No Slope
Compensation (-50 device)
DESCRIPTION
The LM5071 power interface port and pulse width modulation (PWM) controller provides a complete integrated
solution for Powered Devices (PD) that connect into Power over Ethernet (PoE) systems. The LM5071 is
specifically designed for the PD that must accept power from auxiliary sources such as ac adapters. The
auxiliary power interface of the LM5071 activates the PWM controller when the ac adapter is connected to power
the PD when PoE network power is unavailable. The LM5071 integrates an 80V, 400mA line connection switch
and associated control for a fully IEEE 802.3af compliant interface with a full featured current mode pulse width
modulator dc-dc converter. All power sequencing requirements between the controller interface and switch mode
power supply (SMPS) are integrated into the IC.
Packages
• TSSOP-16
Block Diagram
PoE (+)
AC
+
Adapter _
Jack
IEEE
80
2
.3 af
UVL
Interface
SignatureODetection
Classification
LM5071
Hot Swap
DC - DC
Auxiliary
Converter
AUX
Power
In-rusChurarnedntFault
PWM Controller
Enable
Limiting
Current
Mode
VOU
T
Feedback
PoE (-)
1
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
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 © 2005–2006, Texas Instruments Incorporated