LM5071 Power Over Ethernet PD Controller with Auxiliary Power Interface | TI.com

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Power Over Ethernet PD Controller with Auxiliary Power Interface


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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.


  • 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)


  • TSSOP-16

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