LTC4257IDD-1#PBF

Overview

The LTC4257IDD-1#PBF is a Powered Device (PD) interface controller compliant with the IEEE 802.3af standard for Power over Ethernet applications. It integrates a power switch with a maximum on-resistance of 2 Ohms and a current limit of 375 mA. The device operates within a supply voltage range up to -57 V and functions reliably across an extended temperature range from -40°C to +85°C. Designed for surface-mount installation, it utilizes an 8-lead DFN package and draws a typical operating supply current of 3 mA.

Feature Summary

• Provides complete signature detection and power interface control for IEEE 802.3af PD systems
• Integrates a low-loss power switch with built-in current limiting capabilities
• Supports hot insertion and removal without damaging the powered device or network

Applications

• IEEE 802.3af Powered Device power management
• PoE-enabled network endpoints
• Industrial LAN interface controllers

Procurement Notes

Verify component authenticity through authorized Analog Devices distributors. Confirm the specific suffix matches the required package and tape-and-reel specifications. Check for RoHS compliance documentation and ensure the part number corresponds exactly to the IDD-1 variant to avoid pinout or functional mismatches during integration.

Selection Notes

Select this component when designing systems requiring strict adherence to IEEE 802.3af standards. Ensure the application environment supports the specified -40°C to +85°C operating temperature range. Verify that the system voltage does not exceed the -57 V maximum rating and that thermal dissipation requirements align with the DFN-8 package constraints.

Part Context

This part belongs to the LTC4257 family of PoE interface controllers manufactured by Analog Devices Inc. It serves as a specialized solution for managing power delivery in Ethernet-based networks, distinguishing itself through integrated switching and control logic tailored for 802.3af compliance.

Replacement Considerations

Direct substitutes include the LTC4257CS8-1#TRPBF for SOIC-8 packaging and the LTC4257IDD-1#PBF for equivalent DFN-8 configurations. Verify pin compatibility and electrical parameters before swapping.