High-Power Controllers Comply With IEEE 802.3at PoE+ Standard July 02, 2009
Three new high-power controllers—the LTC4269-1, LTC4269-2, and LTC4278—are compliant with the IEEE 802.3at Power over Ethernet (PoE+) standard. The interface controllers have integrated switching regulators for high-power powered device (PD) applications up to 25.5 W. The new IEEE 802.3at definition, also known as the PoE+ standard, simultaneously expands the power budget and improves the classification mechanism used by power sourcing equipment (PSE) and PDs to identify each other. The LTC4269 and LTC4278 support two-event classification and are backward compatible with IEEE 802.3af devices. They integrate both the PD controller and either a synchronous flyback controller (LTC4269-1 and LTC4278) or synchronous forward controller (LTC4269-2) for a complete IEEE 802.3at PD control system. PoE+ applications include video conferencing stations, RFID readers, pan-tilt-zoom security cameras, and long range wireless access points. All versions are offered in commercial and industrial grades, supporting operating temperature ranges from 0°C to 70°C and ?40°C to 85°C, respectively. They come housed in a compact, RoHS-compliant, 7-mm x 4-mm 32-pin DFN package. Pricing for the LTC4269-1 starts at $2.40 each, while pricing for the LTC4269-2 and LTC4278 starts at $2.60 each in 1000-piece quantities. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.
