LTC4268-1 Datasheet | Linear Technology

Features n Robust 35W PD Front End n IEEE 802.3af pliant n Rugged 750m A Power MOSFET With Precision Dual Level Current Limit n High Performance Synchronous Flyback Controller n IEEE Isolation Obtained Without an Opto-Isolator n Adjustable Frequency from 50k Hz to 250k Hz n Tight Multi-Output Regulation With Load pensation n Onboard 25k Signature Resistor n Programmable Classification Current to 75m A n plete Thermal and Over-Current Protection n Available in pact 32-Pin 7mm × 4mm DFN Package Applications n Vo IP Phones With Advanced Display Options n Dual-Radio Wireless Access Points n PTZ Security Cameras n RFID Readers n Industrial Controls n Magnetic Card Readers n High Power Po E Systems High Power PD With Synchronous No-Opto Flyback Controller Description The LTC®4268-1 is an integrated Powered Device (PD) controller and switching regulator intended for IEEE 802.3af and high power Po E applications up to 35W. By including a precision dual current limit, the LTC4268-1 keeps inrush below IEEE 802.3af current limit levels to ensure interoperability success while enabling high power applications with a 750m A operational current limit. The LTC4268-1 synchronous, current-mode, flyback controller generates multiple supply rails in a single conversion providing for the highest system efficiency while maintaining tight regulation across all outputs. The LTC4268-1 includes Linear Technology’s patented No-Opto feedback topology to provide full IEEE 802.3af isolation without the need of opto-isolator circuitry. The oversized power path and high performance flyback controller of the LTC4268-1 bine to make the ultimate solution for power hungry Po E applications such as WAPs, PTZ security cameras, RFID readers and ultra-efficient 802.3af applications running near the 12.95W limit. The LTC4268-1 is available in a space saving 32-pin DFN package. L, LT, LTC, LTM and Switcher CAD are registered trademarks and LTPo E++ and Thin SOT are trademarks of Linear...