POWER LOSS (mW) LTC3869/LTC3869-2 Dual, 2-Phase Synchronous Step-Down DC/DC Controllers Fea T Descrip T n Dual, 180 Phased Controllers Reduce Required The LTC 3869 is a high performance dual synchronous Input Capacitance and Power Supply Induced Noise step-down switching regulator controller that drives all n Accurate Multiphase Current Matching N-channel synchronous power MOSFET stages. A constant n R or DCR Current Sensing frequency current mode architecture allows a phase- SENSE n 0.75% 0.6V Output Voltage Accuracy lockable frequency of up to 780kHz. Power loss and noise n Phase-Lockable Fixed Frequency 250kHz to 780kHz due to the ESR of the input capacitors are minimized by n High Efficiency: Up to 95% operating the two controller output stages out-of-phase. n Dual N-channel MOSFET Synchronous Drive OPTI-LOOP compensation allows the transient response n Wide V Range: 4V to 38V (40V Max) Operation IN to be optimized over a wide range of output capacitance n Wide V Range: 0.6V to 12.5V Operation OUT and ESR values. A wide 4V to 38V input supply range n Adjustable Soft-Start Current Ramping or Tracking encompasses most battery chemistries. Independent TK/ n Foldback Output Current Limiting SS pins for each controller ramp the output voltage during n Output Overvoltage Protection start-up. Current foldback limits MOSFET heat dissipation n Power Good Output Voltage Monitor during short-circuit conditions. The MODE/PLLIN pin n 5V Low Dropout Regulator selects among Burst Mode operation, pulse-skipping n Small 28-Lead QFN and Narrow SSOP Packages mode, or continuous inductor current mode and allows the IC to be synchronized to an external clock. a T The LTC3869 is available in low profile 4mm 4mm and n Server Systems 4mm 5mm QFN packages. The LTC3869-2 is available n Telecom Systems in an SSOP-28 package. The LTC3869 is pin-compatible n Industrial and Medical Instruments with the LTC3850. n High Power Battery-Operated Devices L, LT, LTC, LTM, Linear Technology, the Linear logo, Module, OPTI-LOOP, Burst Mode n DC Power Distribution Systems and PolyPhase are registered trademarks and No R is a trademark of Linear Technology SENSE Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6580258, 6498466, 6611131. Typical a T High Efficiency Dual 5V/3.3V Step-Down Converter Efficiency and Power Loss V IN 7V TO 100 1300 24V V = 12V, V = 3.3V IN OUT + 22F 90 V = 12V, V = 5V IN OUT 1200 4.7F V INTV IN CC 80 1100 TG1 TG2 70 1000 EFFICIENCY BOOST1 BOOST2 60 900 SW1 SW2 50 LTC3869 BG1 BG2 800 40 PGND 700 30 600 + + 20 SENSE2 SENSE1 POWER LOSS 500 10 SENSE1 SENSE2 V V OUT2 OUT1 V V 3.3V 0 400 5V FB1 FB2 0.01 0.1 1 10 5A 5A 147k 90.9k I FREQ + TH1 LOAD CURRENT (A) I 56F 470pF TH2 3869 TA01b 470pF TK/SS1 SGND TK/SS2 + 20k PINS NOT USED IN 47F 122k 20k THIS CIRCUIT: 15k 0.1F 0.1F 15k I , MODE/PLLIN, LIM PGOOD, RUN1, RUN2 3869 TA01 38692fb 1 For more information www.linear.com/LTC3869 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3869/LTC3869-2 a T e Maxi Mu M r a T (Note 1) Input Supply Voltage: V ........................... 40V to 0.3V I , I , V , V Voltages .............INTV to 0.3V IN TH1 TH2 FB1 FB2 CC Top Side Driver Voltages: INTV Peak Output Current ................................100mA CC BOOST1, BOOST2 ...................................... 46V to 0.3V Operating Junction Temperature Range Switch Voltage: SW1, SW2 ........................... 40V to 5V (Note 2) ..................................................40C to 125C INTV , RUN1, RUN2, PGOOD, EXTV , Junction Temperature (Note 3) ............................. 125C CC CC BOOST1-SW1, BOOST2-SW2 ....................... 6V to 0.3V Storage Temperature Range ..................65C to 150C + + SENSE1 , SENSE2 , SENSE1 , Lead Temperature (Soldering, 10 sec) SENSE2 Voltages ......................................13V to 0.3V GN Package ......................................................300C MODE/PLLIN, I , TK/SS1, TK/SS2, LIM FREQ Voltages ......................................INTV to 0.3V CC p c F T TOP VIEW TOP VIEW TOP VIEW 1 FREQ RUN1 28 + 2 27 MODE/PLLIN SENSE1 SENSE1 3 26 SW1 28 27 26 25 24 23 28 27 26 25 24 23 22 SENSE1 1 22 BOOST1 V 4 25 TG1 FB1 TK/SS1 1 21 BOOST1 TK/SS1 2 21 BG1 5 24 BOOST1 TK/SS1 I 2 20 BG1 TH1 I 3 20 V TH1 IN I 6 23 BG1 TH1 V 3 19 V FB1 IN V 4 19 INTV SGND FB1 SGND CC SGND 7 22 V IN V 4 18 INTV FB2 CC 29 29 V 5 18 BG2 FB2 8 INTV I 21 I BG2 TH2 CC 5 17 TH2 I 6 17 PGND TH2 9 20 BG2 TK/SS2 6 16 PGND TK/SS2 TK/SS2 7 16 BOOST2 SENSE2 7 15 BOOST2 V 10 19 PGND FB2 SENSE2 8 15 TG2 11 BOOST2 SENSE2 18 8 9 10 11 12 13 14 9 10 11 12 13 14 + 12 17 TG2 SENSE2 RUN2 13 16 SW2 EXTV 14 15 PGOOD CC UF PACKAGE UFD PACKAGE 28-LEAD (4mm 4mm) PLASTIC QFN 28-LEAD (4mm 5mm) PLASTIC QFN GN PACKAGE T = 125C, = 37C/W, = 2.6C/W JMAX JA JC 28-LEAD PLASTIC SSOP T = 125C, = 34C/W, JMAX JA EXPOSED PAD (PIN 29) IS SGND, MUST BE EXPOSED PAD (PIN 29) IS SGND, MUST BE T = 125C, = 80C/W JMAX JA SOLDERED TO PCB SOLDERED TO PCB o r D i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3869EUF PBF LTC3869EUF TRPBF 3869 40C to 125C 28-Lead (4mm 4mm) Plastic QFN LTC3869IUF PBF LTC3869IUF TRPBF 3869 40C to 125C 28-Lead (4mm 4mm) Plastic QFN LTC3869EUFD PBF LTC3869EUFD TRPBF 3869 28-Lead (4mm 5mm) Plastic QFN 40C to 125C LTC3869IUFD PBF LTC3869IUFD TRPBF 3869 28-Lead (4mm 5mm) Plastic QFN 40C to 125C LTC3869IGN-2 PBF LTC3869IGN-2 TRPBF LTC3869GN-2 28-Lead Narrow Plastic SSOP 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. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: