PoE+ for the Power Hungry PSE PD RETURN SPARE PAIR VDD Tx Rx DATA PAIR LTC4266 PSE CONTROLLER Rx Tx VPORTP RCLASS DATA PAIR LTC4269 VEE PD CONTROLLER/SWITCHER SENSE GATE VOUT VPORTN SPARE PAIR – 54V 0.25 OPTIONAL AUXILIARY POWER Linear Technology now offers a family of Power over Ethernet interface controllers for emerging PoE+ applications, including higher performance wireless access points, PTZ security cameras and RFID readers. The LTC®4266 quad and LTC4274 single PSEs, and LTC4265, LTC4269, LTC4278 PDs are IEEE 802.3at compliant solutions that support the new PoE+ standard with 25.5W of PD power and 2-Event Classification signaling. This new family is fully backward compatible with IEEE 802.3af and unlocks the potential for high power PoE applications. LTC4266 Quad IEEE 802.3at PSE Controller n n n n n n n n n n n n Four Independent PSE Channels Compliant with IEEE 802.3at Type 1 and 2 Lowest Power Dissipation in the Industry - 130mW/Port at 600mA (Including RSENSE and FET) Advanced Power Management - 8-Bit Programmable Current Limit (ILIM) - 7-Bit Programmable Overload Current Limit (ICUT) - Fast Shutdown - 14.5-Bit Port Current/Voltage Monitoring - 2-Event Classification Very High Reliability 4-Point PD Detection: - 2-Point Forced Voltage - 2-Point Forced Current High Capacitance Legacy Device Detection LTC4259A-1 and LTC4258 Pin and Software Compatible Supports 2-Pair and 4-Pair Output Power 1MHz I2C Compatible Serial Control Interface Midspan Backoff Timer Supports Proprietary Very High Power Up to 100W Available in 38-Pin 5mm × 7mm QFN and 36-Pin SSOP Packages Smallest-in-Industry Quad PSE L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. LTC4269-1/LTC4269-2/LTC4278 IEEE 802.3at PD Controllers with Integrated Switchers 25.5W IEEE 802.3at Compliant (Type 2) PD 2-Event Classification Signaling Integrated State-of-the-Art Synchronous No-Opto Flyback Controller (LTC4269-1, LTC4278) or Synchronous Forward Controller (LTC4269-2) Flexible Integrated Auxiliary Power Support Superior EMI Performance Robust 100V 0.7Ω (Typ) Integrated Hot Swap™ MOSFET IEEE 802.3at High Power Available Indicator Integrated Signature Resistor, Programmable Class Current, UVLO, OVLO and Thermal Protection Short-Circuit Protection with Auto-Restart Programmable Soft-Start and Switching Frequency Complementary Power Good Indicators Thermally Enhanced 7mm × 4mm DFN Package n n LTC4269-1, LTC4278 = Simple & Cost-Effective LTC4269-2 = Highest Efficiency n Efficiency vs Load Current 95 n 90 n n n n EFFICIENCY (%) n 85 80 75 n n 42V 50V 57V 70 n 65 0.5 1 1.5 2.5 2 3 3.5 4 4.5 5 LOAD (A) 42692 TA02b LTC4265 IEEE 802.3at PD Controller with 2-Event Classification Recognition n n n n n n n n n IEEE 802.3at Powered Device (PD) Controller 2-Event Classification Signaling Programmable Classification Current Flexible Integrated Auxiliary Power Support Rugged 100V Onboard MOSFET with 100mA Inrush Current Limit Complementary Power Good Outputs Onboard Signature Resistor with Optional Signature Corrupt Comprehensive Thermal Protection Undervoltage and Overvoltage Lockout Available in Compact 12-Pin 4mm × 3mm DFN Package Current Response to a PSE 2-Event Classification Voltage Probe INRUSH PD CURRENT n 1st CLASS 2nd CLASS 40mA TIME DETECTION V1 DETECTION V2 1st MARK 2nd MARK 4265 F04 PoE+ Portfolio: Up to 25.5W-Compliant and 100W Proprietary Power Part Number PSE/PD Channels Description Package (mm) LTC4265 PD 1 IEEE 802.3at High Power PD Interface Controller 4 × 3 DFN-12 LTC4269-1 PD 1 IEEE 802.3at High Power PD Interface Controller and Synchronous No-Opto Flyback Switching Regulator with Auxiliary Support 7 × 4 DFN-32 LTC4269-2 PD 1 IEEE 802.3at High Power PD Interface Controller and Synchronous Forward Converter with Auxiliary Support 7 × 4 DFN-32 LTC4278 PD 1 IEEE 802.3at High Power PD Interface Controller with Synchronous No-Opto Flyback Switching Regulator and 12V Auxiliary Support 7 × 4 DFN-32 LTC4266 PSE 4 Quad IEEE 802.3at Power over Ethernet Controller 5 × 7 QFN-38, SSOP-36 LTC4274 PSE 1 IEEE 802.3at Single Power over Ethernet Controller 5 × 7 QFN-38 www.linear.com/4274 n 1-800-4-LINEAR Info & Samples Telecom, Datacom and Industrial Power Products Brochure www.linear.com/48vsolutions