LTC4278CDKD

Overview

The LTC4278CDKD is a Powered Device (PD) controller designed for IEEE 802.3at PoE applications, housed in a DFN-32 surface-mount package. It integrates a synchronous flyback converter with a no-optocoupler control scheme to provide isolated power conversion. The device supports Class 4 power classification and includes features such as programmable output voltage, soft-start, and comprehensive protection mechanisms including over-voltage, over-current, and thermal shutdown.

Feature Summary

• Integrates a synchronous flyback converter with no-optocoupler control for isolated power generation
• Supports IEEE 802.3at Power over Ethernet Powered Device classification
• Includes integrated high-side and low-side MOSFET switches for efficient power switching

Applications

• IEEE 802.3at Powered Device power supply design
• Isolated power conversion for PoE endpoints
• Network interface cards requiring isolated DC-DC conversion

Procurement Notes

Verify the specific suffix #TRPBF indicates tape-and-reel packaging when ordering. Confirm the DFN-32 package dimensions against your PCB footprint library. Ensure compliance with RoHS directives by checking the manufacturer's environmental declaration. Validate that the operating temperature range meets your system requirements before finalizing procurement.

Selection Notes

Select this component for designs requiring an integrated PoE PD solution with isolation. The no-optocoupler architecture reduces bill of materials count compared to traditional flyback controllers. Consider the DFN-32 package size constraints during layout planning. Verify input voltage compatibility with standard PoE PSE sources.

Part Context

This part belongs to the Analog Devices LTC4278 series of PoE controllers. It is specifically engineered for 802.3at compliant systems. The CDKD variant denotes the commercial temperature range and DFN-32 package type. It serves as a complete solution for generating isolated voltages in networked devices.

Replacement Considerations

Direct substitutes are not explicitly confirmed in public documentation. Evaluate alternative PoE PD controllers from Analog Devices or other manufacturers based on pin compatibility and electrical specifications. Verify regulatory compliance and thermal performance if cross-referencing with similar class devices.