Quad IEEE 802.3af Power over Ethernet Controller with AC Disconnect Features: Controls Four Independent – 48V Powered Ethernet Ports Each LTC4259A-1 Port Includes: – IEEE 802®.3af Compliant PD Detection and Classification – Output Current Limit with Foldback – Short-Circuit Protection with Fast Gate Pull-Down – PD Disconnect Using AC or DC Sensing – Improved AC Disconnect – Improved UVLO Operates Autonomously or Controlled by I2C™ Serial Interface 4-Bit Programmable Digital Address Allows Control of Up to 64 Ports Current and Duty Cycle Limits Protect External FETs IMPROVED UVLO

Single IEEE 802.3af Compliant PSE Controller with Internal Switch Features: IEEE 802.3af Compliant Operation from a Single 48V Supply Fully Autonomous Operation without Microcontroller Internal MOSFET with Thermal Protection Power Management Works Across Multiple Ports with Simple RC Network Precision Inrush Control with Internal Sense Resistor Powered Device (PD) Detection and Classification AC and DC Disconnect Sensing Robust Short-Circuit Protection Pin-Selectable Detection Back-off for Midspan PSEs Classification Dependent ICUT Current Threshold LED Driver Indicates Port On and Blinks Status Codes Available in 14-Pin SO and 4mm × 3mm DFN Packages

Quad IEEE 802.3at Power Over Ethernet Controller Features: Four Independent PSE Channels Compliant with IEEE 802.3at Type 1 and 2 0.34Ω Total Channel Resistance 130mW/Port at 600mA Advanced Power Management 8-Bit Programmable Current Limit (ILIM) 7-Bit Programmable Overload Currents (ICUT) Fast Shutdown of Preselected Ports 14.5-Bit Port Current/Voltage Monitoring 2-Event Classification Very High Reliability 4-Point PD Detection 2-Point Forced Voltage 2-Point Forced Current High Capacitance Legacy Device Detection LTC4259A-1 and LTC4258 Pin and SW Compatible 1MHz I2C Compatible Serial Control Interface Midspan Backoff Timer Supports Proprietary Power Levels Above 25W Available in 38-Pin 5mm × 7mm QFN and 36-Pin SSOP Packages

Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator Features: Complete Power Interface Port for IEEE 802®.3af Powered Device (PD) Onboard 100V, 400mA UVLO Switch Precision Dual Level Inrush Current Limit Integrated Current Mode Switching Regulator Onboard 25kΩ Signature Resistor with Disable Programmable Classication Current (Class 0-4) Thermal Overload Protection Power Good Signal Integrated Error Amplier and Voltage Reference Low Prole 16-Pin SSOP and 3mm × 5mm DFN Packages

Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator Features: Complete Power Interface Port for IEEE 802®.3af Powered Device (PD) Onboard 100V, 400mA UVLO Switch Precision Dual Level Inrush Current Limit Integrated Current Mode Switching Regulator Onboard 25kΩ Signature Resistor with Disable Programmable Classication Current (Class 0-4) Thermal Overload Protection Power Good Signal Integrated Error Amplier and Voltage Reference Low Prole 16-Pin SSOP and 3mm × 5mm DFN Packages

Single PoE+ PSE Controller Features: Compliant with IEEE 802.3at Type 1 and 2 0.34Ω Total Channel Resistance 130mW/Port at 600mA Advanced Power Management 8-Bit Programmable Current Limit (ILIM) 7-Bit Programmable Overload Currents (ICUT) Fast Shutdown 14.5-Bit Port Current/Voltage Monitoring 2-Event Classification Very High Reliability 4-Point PD Detection 2-Point Forced Voltage 2-Point Forced Current High Capacitance Legacy Device Detection LTC4259A-1 and LTC4266 SW Compatible 1MHz I2C Compatible Serial Control Interface Midspan Backoff Timer Supports Proprietary Power Levels Above 25W Available in 38-Pin 5mm × 7mm QFN Package

4-Port IEEE 802.3bt PoE PSE Controller Features: Four PSE Ports Two Power Channels per Port Low Power Path Dissipation per Channel 150mΩ Sense Resistance 30mΩ or Lower MOSFET RDS(ON) Chipset Provides Electrical Isolation Eliminates Optos and Isolated 3.3V Supply Very High Reliability Multipoint PD Detection Connection Check Distinguishes Single-Signature and Dual-Signature PDs Fully Compliant IEEE 802.3bt Type 3 and 4 PSE Compliant Support for Type 1, 2, 3, and 4 PDs Continuous, Dedicated Per-Port Power and Current Monitoring Per-Port Power Policing 1MHz I2C Compatible Serial Control Interface Pin or I2C Programmable PD Power Up to 71.3W Available in a 40-Lead 6mm × 6mm (LTC4292) and 24-Lead 4mm × 4mm (LTC4291-1) QFN Packages

18V Dual Input Micropower PowerPath Prioritizer Features:Selects Highest Priority Valid Supply from Two InputsWide 1.8V to 18V Operating RangeInternal Dual 2Ω, 0.5A SwitchesLow 3.6µA Operating CurrentLow 320nA V2 Current When V1 Connected to OUTBlocks Reverse and Cross Conduction CurrentsReverse Supply Protection to –15VV2 Freshness Seal/Ship Mode±1.5% Accurate Adjustable Switchover ThresholdTwo Auxiliary ±2.3% Accurate Voltage ComparatorsOvercurrent and Thermal ProtectionThermally Enhanced 10-Pin 3mm × 3mm DFN and 12-Lead Exposed Pad MSOP Packages

High Power Prioritized PowerPath Controller Features: 0V to 36V Wide Operating Range (60V Tolerant) Drives Large External N-Channel MOSFETs for High Output Current Applications Accurately Limits Inrush Current Connects Highest Priority Valid Supply to Output Load Changes Channel Priority in Real Time ±2% OV, UV Input Comparators Individually Adjustable Current Limit Time-Out for Each Channel Adjustable Input Validation Time Fast Switchover Minimizes VOUT Droop 36-Lead 5mm × 6mm QFN and SSOP Packages

High Power Prioritized PowerPath Controller Features: 0V to 36V Wide Operating Range (60V Tolerant) Drives Large External N-Channel MOSFETs for High Output Current Applications Accurately Limits Inrush Current Connects Highest Priority Valid Supply to Output Load Changes Channel Priority in Real Time ±2% OV, UV Input Comparators Individually Adjustable Current Limit Time-Out for Each Channel Adjustable Input Validation Time Fast Switchover Minimizes VOUT Droop 36-Lead 5mm × 6mm QFN and SSOP Packages