LTC4257IS8-1#TRPBF

Overview

The LTC4257IS8-1#TRPBF is a Powered Device (PD) power switch IC compliant with the IEEE 802.3af standard for Power over Ethernet (PoE). Manufactured by Analog Devices Inc., it operates within an industrial temperature range of -40°C to +85°C and is housed in an 8-lead SOIC surface-mount package. The device features a maximum on-resistance of 2 ohms and supports a working supply voltage up to 57V, with a typical operating current of 3mA.

Feature Summary

• Integrated control logic for IEEE 802.3af PoE powered devices
• Internal high-side power switch with low on-resistance
• Built-in protection mechanisms against overvoltage and thermal stress

Applications

• IEEE 802.3af compliant network endpoint devices
• VoIP telephones and wireless access points
• Security cameras and surveillance systems
• Industrial sensor nodes requiring PoE power

Procurement Notes

Verify the specific suffix #TRPBF confirms tape-and-reel packaging when sourcing. Confirm the IS8 variant meets industrial temperature requirements (-40°C to +85°C) compared to commercial grades. Ensure compatibility with existing 8-SOIC footprints during procurement planning.

Selection Notes

Select this component for designs strictly adhering to IEEE 802.3af Class 0 or Class 1 power budgets. The 2-ohm on-resistance influences power dissipation; verify thermal management capabilities for the target application environment. Consider the SOIC-8 footprint constraints relative to available board space.

Part Context

This part belongs to the LTC4257 family of PoE PD controllers. It serves as a specialized interface between the Ethernet physical layer and the local DC power bus, simplifying power delivery in networked electronics without requiring external discrete switching components.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation.