LTC4274A/LTC4274C + ++ Single PoE/PoE /LTPoE PSE Controller FEATURES DESCRIPTION n Compliant with IEEE 802.3at Type 1 and 2 The LTC 4274A is a single Power Sourcing Equipment n ++ Low Power Dissipation (PSE) controller capable of delivering up to 90W of LTPoE n ++ power to a compatible LTPoE Powered Device (PD). A 0.25 Sense Resistance Per Channel n proprietary detection/classification scheme allows mutual Very High Reliability 4-Point PD Detection ++ ++ n identification between a LTPoE PSE and LTPoE PD 2-Point Forced Voltage n while remaining compatible and interoperable with existing 2-Point Forced Current Type 1 (13W) and Type 2 (25.5W) PDs. The LTC4274A n High Capacitance Legacy Device Detection 2 feature set is a superset of the popular LTC4274. These n 1MHz I C Compatible Serial Control Interface PSE controllers feature low-R external MOSFETs and n ON Midspan Backoff Timer 0.25 sense resistors which are especially important at n Supports 2-Pair and 4-Pair Output Power ++ the LTPoE current levels to maintain the lowest possible n Available in Multiple Power Grades heat dissipation. n ++ LTC4274A-1: LTPoE 38.7W n ++ LTC4274A-2: LTPoE 52.7W The LTC4274C targets fully automatic PSE systems power- n ++ LTC4274A-3: LTPoE 70W ing Type 1 (up to 13W) PDs. n ++ LTC4274A-4: LTPoE 90W Advanced power management features include: a 14-bit n LTC4274C: PoE 13W current monitoring ADC, DAC-programmable current limit, n Available in 38-Lead 5mm 7mm QFN Package and versatile quick port shutdown. PD Discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. APPLICATIONS 2 The LTC4274A/LTC4274C includes an I C serial interface n ++ LTPoE PSE Switches/Routers operable up to 1MHz. n ++ LTPoE PSE Midspans The LTC4274A/LTC4274C is available in multiple power n IEEE 802.3at Type 1 PSE Switches/Routers grades, allowing delivered PD power of 13W, 25.5W, n IEEE 802.3at Type 1 PSE Midspans 38.7W, 52.7W, 70W and 90W. These controllers are avail- L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ++ LTPoE are trademarks of Analog Devices, Inc. All other trademarks are the property of their able in a 38-lead 5mm 7mm QFN package. respective owners. TYPICAL APPLICATION Complete Single-Port Ethernet High Power Source 10 AD0 AD1 AD2 AD3 SCL SDAIN SDAOUT INT 3.3V V DD AUTO 0.1F SMAJ5.0A + MSD DGND 10F LTC4274AC RESET 10 AGND MID SHDN V SENSE GATE OUT EE + SMAJ58A 1F C BULK 0.22F 100V S1B TVS 100V BULK 54V PORT 4274AC TA01 S1B 54V 4274acfe 1 For more information www.linear.com/LTC4274ALTC4274A/LTC4274C ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION Supply Voltages (Note 1) TOP VIEW AGND V ........................................... 0.3V to 80V EE DGND V ........................................... 0.3V to 80V EE V DGND ......................................... 0.3V to 5.5V DD 38 37 36 35 34 33 32 Digital Pins SDAOUT 1 31 GATE SCL, SDAIN, SDAOUT, INT, SHDN, MSD, AD, NC 2 30 SENSE RESET, AUTO, MID ........... DGND 0.3V to V + 0.3V SDAIN 3 29 NC DD AD3 4 28 NC Analog Pins AD2 5 27 V EE GATE, SENSE, OUT ................ V 0.3V to V + 80V EE EE AD1 6 26 V EE Operating Temperature Range .................40C to 85C V EE AD0 7 25 V 39 EE Junction Temperature (Note 2) ............................. 125C DNC NC 8 24 Storage Temperature Range .................. 65C to 150C NC 9 23 NC Lead Temperature (Soldering, 10 sec) ...................300C DGND 10 22 V EE NC 11 21 NC NC 12 20 NC 13 14 15 16 17 18 19 UHF PACKAGE 38-LEAD (5mm 7mm) PLASTIC QFN EXPOSED PAD IS V (PIN 39) MUST BE SOLDERED TO PCB EE T = 125C, = 34C/W JMAX JA ORDER INFORMATION