LTC4279

LTC4279 Single Port PoE/PoE+/ LTPoE++ PSE Controller FEATURES nn Compliant with IEEE 802.3at Type 1 and 2 nn Supports LTPoE++® Up to 90W nn Supports Dual-Signature PDs nn Fully Autonomous Operation without Microcontroller nn Very Low Power Dissipation – 0.1Ω Sense Resistance – Low RDS(ON) External MOSFET nn Very High Reliability 4-Point PD Detection – 2-Point Forced Voltage and Forced Current nn Robust Short-Circuit Protection nn Cable Surge Protected ±80V OUT Pin nn Classification Dependent ICUT and ILIM Current Thresholds nn Supports 2-Pair and 4-Pair Output Power nn UltraPWR Mode Supports Custom PDs Up to 123W nn Pin-Selectable Detection Backoff Timer for Midspans nn Pin Programmable Legacy PD Detection nn Pin Programmable Maximum Power Mode nn Status LED Pin nn Available in 20-Pin QFN and 16-Pin SO Packages APPLICATIONS nn PoE PSE Endpoints (Switch/Router) nn PoE Midspan Power Injectors nn Power Forwarders nn Femto Cells nn Security Systems DESCRIPTION The LTC®4279 i...