LTC4257IDD-1#TRPBF

Overview

The LTC4257IDD-1 is a Powered Device (PD) power switch IC compliant with IEEE 802.3af standards, designed for Power over Ethernet applications. It operates within a supply voltage range of -57 V and features a maximum on-resistance of 2 Ohms. The device includes an integrated current limit of 375 mA and draws a typical operating supply current of 3 mA. It supports an operating temperature range from -40°C to +85°C and is available in an 8-lead DFN package.

Feature Summary

• Complies with IEEE 802.3af Powered Device standards for PoE integration
• Integrates high-side power switch with internal control logic
• Provides built-in current limiting protection for load safety

Applications

• IEEE 802.3af Powered Device implementations
• Power over Ethernet LAN infrastructure nodes
• Network interface power management circuits

Procurement Notes

Verify the specific suffix TRPBF indicates tape-and-reel packaging when sourcing this component. Confirm that the IDD variant corresponds to the industrial temperature grade requirements for your design environment. Ensure compatibility with standard 8-lead DFN footprints during layout verification.

Selection Notes

Select this part for designs requiring strict adherence to IEEE 802.3af PD specifications. Consider the 2 Ohm on-resistance impact on thermal performance under full load conditions. Evaluate the 375 mA current limit against maximum downstream load requirements to ensure adequate headroom without nuisance tripping.

Part Context

This component belongs to the LTC4257 family of PoE power switches manufactured by Analog Devices. It serves as a specialized solution for integrating power delivery into network devices, distinguishing itself through integrated control features rather than simple passive switching. The IDD designation specifies the industrial temperature range and DFN package configuration.

Replacement Considerations

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