LTC4291IUF-1#PBF

Overview

The LTC4291IUF-1#PBF is a four-port Power Sourcing Equipment (PSE) controller designed for IEEE 802.3bt Type 3 and 4 compliant Power over Ethernet systems. It supports powering compliant 802.3af, 802.3at, and 802.3bt Powered Devices. The device operates with a supply voltage of 3.3 V and functions within a temperature range of -40°C to +85°C. It utilizes low RDS(ON) external MOSFETs and a 0.15Ω sense resistance per channel to minimize heat dissipation. The component is housed in a QFN-24 package.

Feature Summary

• Implements transformer-isolated communication protocol to replace opto-couplers and isolated supplies
• Provides per-port 14-bit current monitoring and programmable current limit
• Supports autoclass and five-event physical classification mechanisms
• Features versatile fast shutdown capability for preselected ports

Applications

• IEEE 802.3bt Type 3 and 4 PoE systems
• Powering 802.3af, 802.3at, and 802.3bt compliant devices
• Four-port power sourcing equipment controllers

Procurement Notes

Verify the specific suffix #PBF indicates lead-free compliance and tube packaging as per Analog Devices standards. Confirm that the IUF-1 designation corresponds to the industrial temperature grade and QFN-24 package variant. Ensure compatibility with the required host interface and software license for advanced power management features before procurement.

Selection Notes

Select this controller for applications requiring low heat dissipation in high-power PoE environments. The integrated transformer-isolated communication reduces bill of materials costs by eliminating complex isolated supplies. Consider the need for host software integration to utilize advanced features like per-port monitoring and fast shutdown capabilities effectively.

Part Context

This component belongs to the LTC4291/LTC4292 chipset family from Analog Devices. These controllers are specifically engineered for multi-port PoE applications, offering industry-leading thermal performance through efficient power path design. The series supports comprehensive detection and classification protocols to ensure safe operation with various Powered Device types.

Replacement Considerations

The LTC4292 is a related model within the same chipset family. Verify if the specific port count or feature set differences between the IUF-1 variant and other available packages meet the design requirements without altering the system architecture.