Description

The LTC® 4266 is a quad Power Sourcing Equipment (PSE) controller designed for use in IEEE 802.3 Type 1 and Type 2 (high power) compliant Power over Ethernet systems. It features external power MOSFETs to enhance system reliability and minimize channel resistance. This allows for lower power dissipation and eliminates the need for heatsinks even at Type 2 power levels. The LTC 4266 is also compatible with the IEEE standard at very high power levels. It has 80V-rated port pins that provide robust protection against external faults.

Specifications and 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 including programmable current limit (ILIM) and 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

- 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

Application Scenarios

- High power PSE switches/routers

- High power PSE midspans

Comparison

Advantages:

- Enhances system reliability with external power MOSFETs

- Minimizes power dissipation and eliminates the need for heatsinks

- Supports very high power levels

- Robust protection against external faults with 80V-rated port pins

Disadvantages:

- None identified