The LTC4290/LTC4271 is an isolated 8-port power source equipment (PSE) controller chipset designed for use in IEEE 802.3at (PoE+) Type 1- and Type 2-compliant Power-over-Ethernet (PoE) systems.This chipset provides 8 independent PSE channels for simpler lower component count designs, reduced board space and ultimately reduced total solution costs.The LTC4271 provides a digital interface to the PSE host, whereas the LTC4290 provides the high voltage Ethernet interface; the two ICs are then bridged by an inexpensive Ethernet transformer.The transformer-isolated communication protocol replaces up to six expensive opto-couplers and a complex isolated 3.3V supply used in traditional designs, resulting in significant cost savings and a more robust and easy to manufacture design.This chipset earns a 100% interoperability score for PoE+ and PoE systems in popular compliance tests. When paired with the LT4275 PD (powered device) controller, complete end-to-end LTPoE++ systems can deliver up to 90W while remaining fully compatible with PoE+ and PoE.Users will appreciate the robustness provided by 80V port pins and lowest-in-industry power dissipation, making thermal design significantly easier than when designing with PSEs integrating more fragile normally-higher-RDS(ON) MOSFETs. The LTC4290 is offered in three power grades: 'A' grade uses Linear Technology's LTPoE++ signaling to support 38.7W, 52.7W, 70W and 90W PDs; 'B' grade uses PoE+ signaling to support up to 25.5W PDs; and 'C' grade uses PoE signaling to support up to 13W PDs. All chipsets are offered in industrial temperature ranges.The LTC4290 is in a RoHS-compliant 40-pin 6mm x 6mm QFN package, while the LTC4271 is in a 24-pin 4mm x 4mm QFN package. The LTC4290/71 chipset is priced starting at $10.00 each in 1,000 piece quantities.
