LTC4267IDHC#TRPBF

Overview

The LTC4267IDHC#TRPBF is a Power Over Ethernet (PoE) Powered Device controller and synchronous buck regulator manufactured by Analog Devices Inc. It integrates an IEEE 802.3af-compliant PD interface with a current-mode switching regulator in a single 16-lead DFN package. The device operates from a -57V input source, typical of PoE systems, and provides regulated output voltages. Key electrical parameters include a maximum operating voltage of -57V, an operating temperature range of -40°C to +85°C, and a signature resistance of 25kΩ. The integrated switch driver supports external MOSFETs for efficient power conversion.

Feature Summary

• Integrates IEEE 802.3af compliant Powered Device interface with a synchronous buck converter
• Includes internal 25kΩ temperature-compensated signature resistor for simplified detection
• Features signature disable capability to interface with non-PoE power sources
• Provides precise dual-level current limiting for large load capacitor charging

Applications

• IEEE 802.3af Powered Device implementations
• Isolated and non-isolated DC-DC conversion for PoE endpoints
• Network infrastructure equipment requiring compact power solutions
• Industrial control systems utilizing PoE power delivery

Procurement Notes

Verify the specific suffix #TRPBF indicates tape and reel packaging when sourcing. Confirm the IDHC variant corresponds to the industrial temperature grade (-40°C to +85°C) and DFN package type. Ensure compatibility with the target PCB footprint for the 16-lead DFN-5x3 package. Cross-reference the manufacturer's latest datasheet for any pinout or electrical specification updates prior to final procurement.

Selection Notes

Select this component when a combined PoE interface and DC-DC converter is required to minimize board space. The integration eliminates the need for separate detection controllers and external bias supplies. Consider the thermal performance of the DFN package for high-power applications. Verify that the external MOSFET selection aligns with the gate drive capabilities provided by the internal switch driver circuitry.

Part Context

This part belongs to the LTC4267 family of PoE controllers designed to simplify Powered Device designs. It replaces traditional two-chip solutions by combining detection, classification, and power conversion functions. The device is intended for applications where size reduction and component count minimization are critical design constraints within PoE-powered network devices.

Replacement Considerations

Compatible evaluation boards include DC804B-A and DC859A for development purposes. Alternative packages such as SSOP-16 may be available under different suffixes like LTC4267CGN-1#PBF, though pinouts and thermal characteristics should be verified against the DFN version.