DESCRIPTION

· The LM5071 is a Power over Ethernet (PoE) Powered Device (PD) controller with an auxiliary power interface, integrating an 80V, 400mA line connection switch and a current mode pulse width modulation (PWM) controller.
· It is designed for PDs that require power from auxiliary sources like AC adapters, activating the PWM controller when PoE network power is unavailable.
· The device ensures full compliance with IEEE 802.3af standards and integrates all power sequencing requirements between the controller interface and switch mode power supply (SMPS).

FEATURES

· Compatible with 12V AC adapters and fully compliant with IEEE 802.3af power interface.
· Includes an 80V, 1Ω, 400mA internal MOSFET and a detection resistor disconnect function.
· Features programmable classification current, under-voltage lockout with programmable hysteresis, and thermal shutdown protection.
· Equipped with an auxiliary power enable pin, current mode pulse width modulator, and supports both isolated and non-isolated applications.
· Includes an error amplifier and reference for non-isolated applications, programmable oscillator frequency, and programmable soft-start.
· Offers 80% maximum duty cycle limiter with slope compensation and 50% maximum duty cycle limiter without slope compensation.

APPLICATIONS

· Suitable for Power over Ethernet (PoE) systems requiring auxiliary power sources.
· Ideal for applications needing a fully IEEE 802.3af compliant interface with integrated current mode PWM controller.
· Used in devices that must switch between PoE and auxiliary power sources seamlessly.