LTC4270/LTC4271 + ++ 12-Port PoE/PoE /LTPoE PSE Controller FEATURES DESCRIPTION n 12 Independent PSE Channels The LTC 4270/LTC4271 chipset is a 12-port power sourc- n Compliant with IEEE 802.3at Type 1 and 2 ing equipment (PSE) controller designed for use in IEEE n Chipset Provides Electrical Isolation 802.3at Type 1 and Type 2 (high power) compliant Power n Reduced BOM Cost over Ethernet (PoE) systems. Transformer-isolated com- n Eliminates up to 6 High Speed Opto-Couplers munication protocol replaces expensive opto-couplers n Eliminates Isolated 3.3V Power Supply and complex isolated 3.3V supply resulting in significant n Low Power Dissipation BOM cost savings. The LTC4270/LTC4271 chipset delivers n 0.25 Sense Resistance Per Channel lowest-in-industry heat dissipation by utilizing low-R DS(ON) n Very High Reliability 4-Point PD Detection external MOSFETs and 0.25 sense resistors. n 2-Point Forced Voltage Advanced power management features include per-port n 2-Point Forced Current 12-bit current monitoring ADCs, DAC-programmable cur- n V and V Monitoring EE PORT rent limit, and versatile fast shut-down of preselected ports. n 1 Second Rolling I Averaging PORT Advanced power management host software is available n Supports 2-Pair and 4-Pair Output Power under a no-cost license. PD discovery uses a proprietary 2 n 1MHz I C Compatible Serial Control Interface dual-mode 4-point detection mechanism ensuring excel- n Available In Three Power Grades lent immunity from false PD detection. Midspan PSEs n ++ A-Grade LTPoE 38.7W to 90W are supported with 2-event classification and a 2 second n + B-Grade PoE 25.5W 2 backoff timer. The LTC4270/LTC4271 includes an I C n C-Grade PoE 13W serial interface operable up to 1MHz. n Available In 52-Lead 7mm 8mm (LTC4270) and The LTC4270/LTC4271 is available in multiple power 24-Lead 4mm 4mm (LTC4271) QFN Packages grades allowing delivered PD power up to 90W. APPLICATIONS L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks ++ and LTPoE is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n PoE PSE Switches/Routers n PoE PSE Midspans TYPICAL APPLICATION 3.3V 0.1F V XIO0 XIO1 GP0 0.22F DD33 LTC4270/LTC4271 FAMILY S1B 100V GP1 NO ISOLATION OUTn CPD CPA PORTn MID MAX REQUIRED ON 2 100 100 I C INTERFACE RESET LTC4270 DELIVERED GATEn S1B MSD 3.3V 54V ++ + GRADE ISOLATION LTPoE PoE PoE POWER AUTO 0.25 100 100 INT SENSEn 54V A Transformer l l l 90W CND CNA LTC4271 LTC4270 SCL 0.22F DPD DPA B Transformer l l 25.5W SDAIN 100V S1B SDAOUT 100 100 C Transformer l 13W OUT1 PORT1 3.3V 54V AD0 AD1 100 100 S1B GATE1 AD2 0.25 DND DNA AD3 SENSE1 54V 10 AD6 DGND CAP1 AGND CAP2 V VSSK EE 1F 0.1F + >47F 2nF 2kV 1F SYSTEM BULK CAP 54V 54V 42701fd 42701 TA01a 1 For more information www.linear.com/LTC4270LTC4270/LTC4271 ABSOLUTE MAXIMUM RATINGS LTC4270 (Note 1, Note 4) Supply Voltages Operating Ambient Temperature Range AGND V ........................................... 0.3V to 80V LTC4270I .............................................40C to 85C EE VSSK (Note 7) ..................... V 0.3V to V + 0.3V Junction Temperature (Note 2) ............................ 125C EE EE Digital Pins Storage Temperature Range ......................65 to 150C XIOn ................................. V 0.3V to CAP2 + 0.3V EE Analog Pins SENSEn, GATEn, OUTn ........ V 0.3V to V + 80V EE EE CAP2 (Note 13) ....................... V 0.3V to V + 5V EE EE CPA, CNA, DPA, DNA ..............V 0.3V to V + 0.3 EE EE ABSOLUTE MAXIMUM RATINGS LTC4271 (Note 1) Supply Voltages Analog Pins V DGND ......................................... 0.3V to 3.6V CAP1 (Note 13) ...........................0.3V to DGND + 2V DD Digital Pins CPD, CND, DPD, DND ..........DGND 0.3 to V + 0.3 DD SCL, SDAIN, SDAOUT, INT, RESET, MSD, ADn, AUTO, Junction Temperature (Note 2) ............................ 125C MID, GPn ........................DGND 0.3V to V + 0.3V Storage Temperature Range ......................65 to 150C DD Operating Ambient Temperature Range LTC4271I..............................................40C to 85C 42701fd 2 For more information www.linear.com/LTC4270