The LTC4266IUHF#TRPBF is a quad PSE controller designed for use in IEEE 802.3 Type 1 and Type 2 (high power) compliant 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 components also allow use at very high power levels while remaining otherwise compatible with the IEEE standard. 80V-rated port pins provide robust protection against external faults.
The LTC4266IUHF#TRPBF includes advanced power management features, including current and voltage readback and programmable ICUT and ILIM thresholds. Available C libraries simplify power-management software development; an optional AUTO pin mode provides fully IEEE-compliant 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 backoff timing. Host communication is via a 1MHz I2C serial interface.
The LTC4266IUHF#TRPBF is available in a 5mm × 7mm QFN package that significantly reduces board space compared with competing solutions. A legacy-compatible 36-pin SSOP package is also available.
Feature
Four Independent PSE Channels
Compliant with IEEE 802.3at Type 1 and 2
0.34Ω Total Channel Resistance
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
Applications
Catalogue
FPGA / CPLD
Memory
MOS 
MCU 
DSP
OCEP
Secondary 
Other 
