LM5070

LM5070 Integrated Power Over Ethernet PD Interface and PWM Controller March 2005 LM5070 Integrated Power Over Ethernet PD Interface and PWM Controller General 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 a 76V, 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. Features n Fully Compliant 802.3af Power Interface Port n 76V, 1Ω, 400 mA Internal MOSFET n Programmable Inrush Current Limit n Detection Resistor Disconnect Function n Programmable Classification Current n Programmable Under-voltage Lockout with Programmable Hysteresis n Thermal Shutdown Protection n Current Mode Pulse Width Modulator n Supports both Isolated and Non-Isolated Applications n Error Amplifier and Reference for Non-Isolated Applications n Programmable Oscillator Frequency n Programmable Soft-start n 80% Maximum Duty Cycle Limiter, Slope Compensation (-80 device) n ...