LTC4274 Datasheet | Linear Technology

LTC4274 Single Po E+ PSE Controller Features nn pliant with IEEE 802.3at Type 1 and 2 nn 0.34Ω Total Channel Resistance nn 130m W/Port at 600m A nn Advanced Power Management nn 8-Bit Programmable Current Limit (ILIM) nn 7-Bit Programmable Overload Currents (ICUT) nn Fast Shutdown nn 14.5-Bit Port Current/Voltage Monitoring nn 2-Event Classification nn Very High Reliability 4-Point PD Detection nn 2-Point Forced Voltage nn 2-Point Forced Current nn High Capacitance Legacy Device Detection nn LTC4259A-1 and LTC4266 SW patible nn 1MHz I2C patible Serial Control Interface nn Midspan Backoff Timer nn Supports Proprietary Power Levels Above 25W nn Available in 38-Pin 5mm × 7mm QFN Package Applications nn PSE Switches/Routers nn PSE Midspans L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Thin SOT and LTPo E++ are trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. Description The LTC®4274 is a single power sourcing equipment controller designed for use in IEEE 802.3 Type 1 and Type 2 (high power) pliant Power over Ethernet systems. External power MOSFETs enhance system reliability and minimize channel resistance, cutting power dissipation and eliminating the need for heatsinks even at Type 2 power levels. External power ponents also allow use at very high power levels while remaining otherwise patible with the IEEE standard. 80V-rated port pins provide robust protection against external faults. The LTC4274 includes advanced power management Features , including current and voltage readback and programmable ICUT and ILIM thresholds. Available C libraries simplify software development; an optional AUTO pin mode provides fully IEEE-pliant standalone operation with no software required. Proprietary 4-point PD detection circuitry minimizes false PD detection while supporting legacy phone operation. Midspan operation is supported with built-in 2-event classification and...