The LTC4257IS8-1 is a sophisticated interface controller designed for Power over Ethernet (PoE) applications and conforms to the IEEE 802.3af standard. Manufactured by Linear Technology, now part of Analog Devices, this controller is an integral component for devices that require power supplied over Ethernet cables, commonly known as Powered Devices (PDs).

Key Features

• IEEE 802.3af Compliant: The LTC4257IS8-1 adheres to the stringent specifications of the IEEE 802.3af standard, ensuring compatibility with other compliant devices in a PoE system.
• Integrated Signature Resistor: This device includes an integrated 25kΩ signature resistor, which is used by Power Sourcing Equipment (PSE) to detect a compliant PD.
• Classification Current: It supports classification current, allowing the PSE to determine the power classification of the PD.
• High Voltage Interface: The controller is capable of withstanding voltages up to 100V, making it robust against surges and over-voltage conditions.
• Thermal Protection: Built-in thermal protection features prevent the device from overheating, ensuring reliability and longevity.
• Compact Package: The LTC4257IS8-1 is available in a narrow SO-8 package, suitable for space-constrained applications.

Applications

The LTC4257IS8-1 is ideal for a variety of applications that require remote power delivery. This includes:

• VoIP Phones
• Wireless Network Access Points
• Security Cameras
• Network Routers and Switches
• Industrial Controllers

Product Specifications

The LTC4257IS8-1 operates within the commercial temperature range of 0°C to 70°C. It features a supply voltage range typically between 44V to 57V, as specified by the PoE standard. The controller's low power dissipation and efficient operation make it an excellent choice for PD applications that require minimal energy waste and heat generation.

Conclusion

Overall, the LTC4257IS8-1 from Linear Technology is a robust and reliable solution for any application that demands a Power over Ethernet interface controller. Its compliance with industry standards, integrated features, and compact form factor make it a top choice for designers and engineers looking to incorporate PoE capabilities into their products.