LTC4268-1 High Power PD With Synchronous No-Opto Flyback Controller Fea T Descrip T n Robust 35W PD Front End The LTC 4268-1 is an integrated Powered Device (PD) n IEEE 802.3af Compliant controller and switching regulator intended for IEEE 802.3af n Rugged 750mA Power MOSFET With Precision Dual and high power PoE applications up to 35W. By including Level Current Limit a precision dual current limit, the LTC4268-1 keeps inrush n High Performance Synchronous Flyback Controller below IEEE 802.3af current limit levels to ensure interop- n IEEE Isolation Obtained Without an Opto-Isolator erability success while enabling high power applications n Adjustable Frequency from 50kHz to 250kHz with a 750mA operational current limit. n Tight Multi-Output Regulation With Load The LTC4268-1 synchronous, current-mode, flyback Compensation controller generates multiple supply rails in a single n Onboard 25k Signature Resistor conversion providing for the highest system efficiency n Programmable Classification Current to 75mA while maintaining tight regulation across all outputs. The n Complete Thermal and Over-Current Protection LTC4268-1 includes Linear Technologys patented No-Opto n Available in Compact 32-Pin 7mm 4mm DFN feedback topology to provide full IEEE 802.3af isolation Package without the need of opto-isolator circuitry. a T The oversized power path and high performance flyback controller of the LTC4268-1 combine to make the ultimate n VoIP Phones With Advanced Display Options solution for power hungry PoE applications such as WAPs, n Dual-Radio Wireless Access Points PTZ security cameras, RFID readers and ultra-efficient n PTZ Security Cameras 802.3af applications running near the 12.95W limit. n RFID Readers n The LTC4268-1 is available in a space saving 32-pin DFN Industrial Controls n package. Magnetic Card Readers n High Power PoE Systems L, LT, LTC, LTM and SwitcherCAD are registered trademarks and LTPoE++ and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5841643. Typical a T 35W High Efficiency PD Solution 3.3V + 470F 5F 100pF 4 BAS21 28.7k T1 47k 1% 47 T1 56 SMAJ58A 20 100k B0540W DF1501S 3.01k FMMT618 1% 47F ~ + Si4490DY Si7336ADP 54V FROM DATA PAIR ~ FMMT718 + 0.1F V PWRGD PWRGD UVLO I V FB PG SENSE PORTP LIM EN CC DF1501S 1F 0.02 SHDN ~ + 54V FROM SPARE PAIR ~ SENSE 15 LTC4268-1 330 R CLASS SG 0.1F 2.2nF V CMP T2 V V PGDLY t SYNC R ENDLY OSC GND SFST C PORTN NEG ON CMP CMP 10nF R 12k 169k 100k 10k CLASS BAT54 T1: PA1477NL 20k 47pF T2: PA0184 42681 TA01a 0.033F 42681fc 1 + ion pplica ions pplica ion uresLTC4268-1 a Te Maxi Mu M r a T p c F T (Notes 1, 2) TOP VIEW V Voltage .......................................... 0.3V to 90V PORTN SHDN 1 32 V PORTP V Voltage ..................V + 90V to V 0.3V NEG PORTN PORTN NC 2 31 NC V to GND Voltage (Note 3) CC R 3 30 PWRGD CLASS Low Impedance Source ......................... 0.3V to 18V I 4 29 PWRGD LIM EN Current Fed ..........................................30mA into V CC V 5 28 V PORTN NEG R , I Voltage ..V + 7V to V 0.3V CLASS LIM EN PORTN PORTN V 6 27 V PORTN NEG SHDN Voltage ...............V + 90V to V 0.3V PORTN PORTN V 7 26 V PORTN NEG PWRGD Voltage (Note 3) NC 8 25 NC 33 Low Impedance Source .... V + 11V to V 0.3V NEG NEG SG 9 24 PG Current Fed ..........................................................5mA V 10 23 PGDLY CC PWRGD Voltage ............V + 80V to V 0.3V t 11 22 R PORTN PORTN ON CMP PWRGD Current .....................................................10mA ENDLY 12 21 C CMP SYNC 13 20 SENSE+ R Current ....................................................100mA CLASS + SFST 14 19 SENSE SENSE , SENSE Voltage ........................ 0.5V to +0.5V OSC 15 18 UVLO UVLO, SYNC Voltage ...................................0.3V to V CC FB 16 17 V CMP FB Current ..............................................................2mA V Current ......................................................... 1mA CMP DKD32 PACKAGE 32-LEAD (7mm 4mm) PLASTIC DFN Operating Ambient Temperature Range (Notes 4, 5) T = 150C, = 49C/W, = 4.7C/W JMAX JA JC LTC4268-1C ............................................. 0C to 70C EXPOSED PAD (PIN 33) MUST BE SOLDERED TO HEAT SINKING PLANE THAT IS ELECTRICALLY CONNECTED TO GND LTC4268-1I ..........................................40C to 85C Junction Temperature (Note 5) ............................. 150C Storage Temperature Range .................. 65C to 150C o r D i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4268CDKD-1 PBF LTC4268CDKD-1 TRPBF 42681 32-Lead (7mm 4mm) Plastic DFN 0C to 70C LTC4268IDKD-1 PBF LTC4268IDKD-1 TRPBF 42681 32-Lead (7mm 4mm) Plastic DFN 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4268CDKD-1 LTC4268CDKD-1 TR 42681 32-Lead (7mm 4mm) Plastic DFN 0C to 70C LTC4268IDKD-1 LTC4268IDKD-1 TR 42681 32-Lead (7mm 4mm) Plastic DFN 40C to 85C 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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