LM5070 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – Integrated Power Over Ethernet PD Interface and PWM Controller

LM5070
www.ti.com
SNVS308G – OCTOBER 2004 – REVISED APRIL 2013
LM5070 Integrated Power Over Ethernet PD Interface and PWM Controller
Check for Samples: LM5070
FEATURES
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•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
• WSON-16 (5 mm x 5 mm)
Block Diagrams
RJ45
Connector
TX+ (1)
TX- (2)
RX+ (3)
RX- (6)
(4)
(5)
To PHY
To PHY
VDC
IEEE 802.3af
Interface
UVLO
Signature Detection
Classification
Hot Plug Controller
In-rush and Fault
Current Limiting
LM5070
DC-DC
Converter
Controller
Current Mode
(7)
(8)
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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.
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