LTC4291IUF#PBF

Overview

The LTC4291IUF#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 features a maximum on-resistance of 150 mOhms. It delivers up to 71.3 W output power per port. The component functions within an operating temperature range from -40°C to +85°C and is housed in a QFN-24 package.

Feature Summary

• Utilizes transformer-isolated communication protocol to replace opto-couplers
• Supports autoclass and five-event physical classification mechanisms
• Provides per-port 14-bit current monitoring capabilities
• Features programmable current limit and versatile fast shutdown

Applications

• IEEE 802.3bt Type 3 PoE system design
• IEEE 802.3bt Type 4 PoE system design
• Multi-port PSE controller integration
• Powered Device detection and classification

Procurement Notes

Verify the specific suffix #PBF indicates lead-free compliance when sourcing. Confirm the QFN-24 package dimensions match your PCB footprint requirements. Ensure the host interface specifications align with your control logic. Check for any recent Product Change Notifications that may affect pinout or electrical characteristics before finalizing procurement.

Selection Notes

Select this component for applications requiring high-density PoE power distribution with low heat dissipation. The integrated digital control host interface simplifies system management compared to analog alternatives. Consider the 150 mOhms on-resistance impact on thermal performance under full load conditions. Verify compatibility with the required IEEE 802.3 standard version for your target deployment.

Part Context

This part belongs to the LTC4291/LTC4292 chipset family manufactured by Analog Devices. It serves as a specialized controller for managing power delivery in advanced Ethernet infrastructure. The series focuses on reducing bill-of-materials costs through integrated isolation techniques. It addresses the growing demand for higher power budgets in modern network devices.

Replacement Considerations

The LTC4292 is a compatible alternative within the same chipset family. Both parts share similar functionality for IEEE 802.3bt Type 3 and 4 applications. Verify pin-to-pin compatibility and software configuration requirements before substitution.