LM5070_14 Datasheet, PDF (1/23 Pages) Texas Instruments – Integrated Power Over Ethernet PD Interface and PWM Controller

LM5070
www.ti.com
SNVS308F – OCTOBER 2004 – REVISED APRIL 2006
LM5070 Integrated Power Over Ethernet PD Interface and PWM Controller
Check for Samples: LM5070
FEATURES
1
•2 Fully Compliant 802.3af Power Interface Port
• 80V, 1Ω, 400 mA Internal MOSFET
• Programmable Inrush Current Limit
• Detection Resistor Disconnect Function
• Programmable Classification Current
• Programmable Under-voltage Lockout with
Programmable Hysteresis
• Thermal Shutdown Protection
• 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)
• 800 mA Peak Gate Driver
DESCRIPTION
The LM5070 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 LM5070 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. Two options are
available providing either an 80% maximum duty cycle limit with slope compensation (on the –80 suffix) device or
a 50% maximum duty cycle limit and no slope compensation on the (–50 suffix) device.
Packages
• TSSOP-16
• LLP-16 (5 mm x 5 mm)
Block Diagrams
RJ4
Conn5ecto
r
TX+ (1)
TX- (2)
RX+ (3)
RX- (6)
(4)
(5)
(7)
(8)
To PHY
To PHY
VDC
IEEE
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e
SiUgnVaLtOure
CDlaestseicfitcioantio
n
Hot Plug
Controller
In-rush and
CFuarrueltnt
Limiting
LM5070
CDoCnv-DerCte
Conrtrolle
r
Current Mode
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.
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 © 2004–2006, Texas Instruments Incorporated