LT4276 ++ + LTPoE /PoE /PoE PD Forward/Flyback Controller Fea T Descrip T n ++ IEEE802.3af/at and LTPoE 90W Powered Device The LT 4276 is a pin-for-pin compatible family of IEEE ++ (PD) with Forward/Flyback Controller 802.3 and LTPoE Powered Device (PD) controllers. It n LT4276A Supports All of the Following Standards: includes an isolated switching regulator controller capable n ++ LTPoE 38.7W, 52.7W, 70W and 90W of synchronous operation in both forward and flyback n IEEE 802.3at 25.5W Compliant topologies with auxiliary power support. n IEEE 802.3af up to 13W Compliant ++ The LT4276A employs the LTPoE classification scheme, n LT4276B is IEEE 802.3at/af Compliant receiving 38.7W, 52.7W, 70W or 90W of power at the PD n LT4276C is IEEE 802.3af Compliant RJ45 connector, and is backwards compatible with IEEE n Superior Surge Protection (100V Absolute Maximum) 802.3. The LT4276B is a fully 802.3at compliant, 25.5W n Wide Junction Temperature Range (40C to 125C) + Type 2 (PoE ) PD. The LT4276C is a fully 802.3af compli- n Auxiliary Power Support as Low as 9V ant, 13W Type 1 (PoE) PD. n No Opto-Isolator Required for Flyback Operation n The LT4276 supports both forward and flyback power External Hot Swap N-Channel MOSFET for Lowest supply topologies, configurable for a wide range of PoE Power Dissipation and Highest System Efficiency n applications. The flyback topology supports No-Opto >94% End-to-End Efficiency with LT4321 Ideal Bridge n feedback. Auxiliary input voltage can be accurately sensed Available in a 28-Lead 4mm 5mm QFN Package with just a resistor divider connected to the AUX pin. a T The LT4276 utilizes an external, low R N-channel DS(ON) n High Power Wireless Data Systems MOSFET for the Hot Swap function, maximizing power n Outdoor Security Camera Equipment delivery and efficiency, reducing heat dissipation, and n Commercial and Public Information Displays easing the thermal design. n ++, High Temperature Applications L, LT, LTC, LTM, LTPoE Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical a T + ++ LTPoE 70W Power Supply in a Forward Mode AUX LT4276 Family 37V-57V LT4276 + + GRADE MAX DELIVERED V PORT 22F + 5V FMMT723 POWER A B C 13A 0.1F 100H 3.3k ++ LTPoE 90W l 10nF BAV19WS 10F ++ l LTPoE 70W (T 50ns) RR ++ LTPoE 52.7W l VPORT HS V HS SW V FFS PG IN CC GATE SRC VCC DLY V CC + AUX ISEN ++ l LTPoE 38.7W 20m LT4276A 25.5W l l ISEN R CLASS l l l SG 13W R ++ CLASS 100pF 0.1F 10k GND FB31 SS ROSC T2P ITHB 4276 TA01 100k OPTO TO MICROPROCESSOR 4276fa 1 For more information www.linear.com/LT4276 ion pplica ions pplica ion uresLT4276 a Te Maxi Mu M r a T p in c F T (Notes 1, 2) TOP VIEW VPORT, HSSRC, V Voltages .....................0.3 to 100V IN HSGATE Current.................................................. 20mA V Voltage .................................................... 0.3 to 8V CC 28 27 26 25 24 23 ++ RCLASS, RCLASS GND 1 22 DNC Voltages .................................0.3 to 8V (and VPORT) AUX 2 21 V CC ++ RCLASS /NC* 3 20 PG SFST, FFSDLY, ITHB, T2P Voltages ......0.3 to V +0.3V CC 29 RCLASS 4 19 GND + ISEN , ISEN Voltages ...........................................0.3V GND T2P/NC** 5 18 SG FB31 Voltage ..................................................+12V/30V + V 6 17 ISEN CC ++ RCLASS/RCLASS Current .............................. 50mA V 7 16 ISEN CC AUX Current ........................................................ 1.4mA V 8 15 RLDCMP CC ROSC Current ..................................................... 100A 9 10 11 12 13 14 RLDCMP Current ................................................500A T2P Current .........................................................2.5mA UFD PACKAGE Operating Junction Temperature Range (Note 3) 28-LEAD (4mm 5mm) PLASTIC QFN LT4276AI/LT4276BI/LT4276CI ..............40C to 85C T = 150C, = 3.4C/W JMAX JC EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB LT4276AH/LT4276BH/LT4276CH ....... 40C to 125C ++ Storage Temperature Range .................. 65C to 150C *RCLASS is not connected in the LT4276B and LT4276C **T2P is not connected in the LT4276C o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* MAX PD POWER PACKAGE DESCRIPTION TEMPERATURE RANGE LT4276AIUFD PBF LT4276AIUFD TRPBF 4276A 90W 28-Lead (4mm 5mm) Plastic QFN 40C to 85C LT4276AHUFD PBF LT4276AHUFD TRPBF 4276A 90W 28-Lead (4mm 5mm) Plastic QFN 40C to 125C LT4276BIUFD PBF LT4276BIUFD TRPBF 4276B 25.5W 28-Lead (4mm 5mm) Plastic QFN 40C to 85C LT4276BHUFD PBF LT4276BHUFD TRPBF 4276B 25.5W 28-Lead (4mm 5mm) Plastic QFN 40C to 125C LT4276CIUFD PBF LT4276CIUFD TRPBF 4276C 13W 28-Lead (4mm 5mm) Plastic QFN 40C to 85C LT4276CHUFD PBF LT4276CHUFD TRPBF 4276C 13W 28-Lead (4mm 5mm) Plastic QFN 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. 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