LTC4291IUF#TRPBF

Overview

The LTC4291IUF#TRPBF is a 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 (PDs). The device operates on a single 3.3V supply voltage with a maximum operating temperature of +85°C and a minimum of -40°C. It utilizes low-RDS(ON) external MOSFETs and features a 0.15Ω sense resistance per power channel to minimize heat dissipation. The component is housed in a QFN-24 package.

Feature Summary

• Integrates transformer-isolated communication protocol to replace opto-couplers and complex isolated supplies
• Provides per-port 14-bit current monitoring and programmable current limit capabilities
• Supports advanced PD detection using a proprietary multipoint mechanism for false identification immunity
• Enables versatile fast shut-down of preselected ports for precise power management

Applications

• IEEE 802.3bt Type 3 and 4 PoE system implementations
• Power sourcing equipment controllers for network infrastructure
• Systems requiring powered devices compliant with 802.3af/at/bt standards

Procurement Notes

Verify the specific suffix #TRPBF indicates tape and reel packaging when ordering. Confirm that the I-grade designation corresponds to the industrial temperature range requirements of your application. Ensure compatibility with the host software license if utilizing advanced power management features. Cross-reference the datasheet for exact pinout and electrical characteristics before finalizing procurement specifications.

Selection Notes

Select this component for designs requiring integrated PSE control with low heat dissipation. It is suitable for applications needing high accuracy current monitoring via 14-bit resolution. Consider the QFN-24 package constraints for PCB layout. Evaluate the need for transformer-isolated communication versus other isolation methods based on bill of materials cost targets.

Part Context

This part belongs to the LTC4291/LTC4291 chipset family from Analog Devices. The series is specifically engineered for 4-port PoE controllers. It falls under the category of Switch ICs within the broader PMIC classification. The manufacturer is Analog Devices Inc., formerly Linear Technology.

Replacement Considerations

The LTC4292 is a related chipset member designed for similar 4-port PoE applications. Verify functional equivalence regarding port count and IEEE standard compliance before substitution.