POWER LOSS (W) LTC3815 6A Monolithic Synchronous DC/DC Step-Down Converter with Digital Power System Management Features Description n 2.25V to 5.5V Input Voltage Range The LTC 3815 is a high efficiency, 6A monolithic synchro- n 1% Total Output Voltage Accuracy Over nous buck regulator using a phase lockable controlled Temperature at V = 3.3V or 5V on-time, current mode architecture. The output voltage IN n Single Resistor-Programmable Output Voltage is programmable from 0.4V to 72% of V with a single IN n PMBus Compliant Serial Interface: external resistor or an external voltage reference through n Programmable Output Voltage Margining: the reference input (REF) pin. The output voltage can be Up to 25% V Range with 0.1% Resolution OUT margined up or down up to 25% with 0.1% resolution n Read back of Average and Peak Temperature, via a PMBus-compliant serial interface. The serial inter- Current, and Voltage (25Hz Refresh Rate) face can also be used to read back fault status and both n Fault Status time-averaged (~4ms) and peak input/output current, n Phase-Lockable Fixed Frequency Up to 3MHz input/output voltage and temperature. System configura- n Less Than 1ms Power-Up Time tion and monitoring is supported by the LTpowerPlay n Integrated 13-Bit ADC development system. n Optional External Reference Input The architecture provides extremely fast transient response n Pin Selectable Fast-Margining of the Output Voltage and allows operation at the very low on-times required to n Power Good Flag with Pin Programmable Thresholds regulate low output voltages at high switching frequencies. and Filter Delay The operating frequency is programmable from 400kHz n Differential Remote Output Voltage Sensing to 3MHz with an external resistor or for noise sensitive n Master Shutdown Mode: <1A Supply Current n applications, it can be synchronized to an external clock Clock Out for 2-Phase Operation (12A Output Current) n over the same range. The operating supply voltage range Available in a Thermally-Enhanced 38-Lead is from 2.25V to 5.5V making it suitable for operation from 4mm 6mm QFN Package 2.5V, 3.3V or 5V rails or Lithium-Ion batteries. a pplications L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap and LTPowerPlay are trademarks of Linear Technology Corporation. All other n Intelligent Energy Efficient Power Conversion trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, 5408150, 7420359. Licensed n ASIC/FPGA/Processor Power under U.S. Patent 7000125 and other related patents worldwide. n Distributed Power Systems n Point of Load Power Conversion t a Efficiency and Power Loss vs Load Current V IN 2.25V TO 5.5V 10 100 C V = 1.8V IN OUT PV V IN IN 90 LTC3815 80 EFFICIENCY MODE/SYNC PGLIM 70 R TRACK/SS 1 T RUN MSTR RUN STBY 60 L V OUT 50 SCL, SDA, ALERT PMBUS SW 0.4V TO 0.72*V IN V 6A CC SENSE 40 MARGIN POWER LOSS C 0.1 OUT V WP 30 SS SENSE R PGOOD C1 20 DA OUT V = 2.8V CLKOUT IN V = 3.3V CSLEW FB 10 IN V = 5V IN REF I TH 0 0 ASEL PGFD R C2 10 100 1000 10000 C C2 LOAD CURRENT (mA) 3815 TA01a 3815 TA01b 3815f 1 For more information www.linear.com/LTC3815 EFFICIENCY (%) pplication ypicalLTC3815 a bsolute Maxi MuM r atings p c Figuration (Notes 1, 7) TOP VIEW V , P ....................................................... 0.3V to 6V IN VIN V , V , C , R , I , MODE/SYNC, CC SENSE SS SENSE SLEW T TH REF, TRACK/SS, PGFD, PGLIM, ASEL, DA , MARGIN, OUT 38 37 36 35 34 33 32 RUN STBY, FB .............................. 0.3V to (V + 0.3V) IN R 1 31 V T SS SENSE RUN MSTR, PGOOD, ALERT, SCL, ASEL 2 30 TRACK/SS SDA Voltage ............................................. 0.3V to 6V MARGIN 3 29 PGOOD WP 4 28 C WP ............................................................ 0.3V to 2.5V SLEW ALERT 5 27 RUN STBY Operating Junction Temperature Range CLKOUT 6 26 RUN MSTR 39 (Notes 2, 3) ............................................ 40C to 125C PGND SDA 7 24 PGFD Storage Temperature Range .................. 65C to 125C SCL 8 24 V IN MODE/SYNC 9 23 SW SW 10 22 SW SW 11 21 SW NC 12 20 NC 13 14 15 16 17 18 19 UFE PACKAGE 38-LEAD (4mm 6mm) PLASTIC QFN T = 125C, = 38C/W JMAX JA EXPOSED PAD (PIN 39) IS PGND, MUST BE SOLDERED TO PCB o r D i n F M LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3815EUFE PBF LTC3815EUFE TRPBF 3815 38-Lead (4mm 6mm) Plastic QFN 40C to 125C LTC3815IUFE PBF LTC3815IUFE TRPBF 3815 38-Lead (4mm 6mm) 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. For more information on lead free part marking, go to: