LTC3853 Triple Output, Multiphase Synchronous Step-Down Controller FEATURES DESCRIPTION n Triple, 120 Phased Controllers Reduce Required The LTC 3853 is a high performance triple output step- Input Capacitance and Power Supply Induced Noise down switching regulator controller that drives all N- n Configurable as a 180 Dual Phase Controller Plus a channel synchronous power MOSFET stages. Power loss Single Phase Controller and supply noise are minimized by operating the output n The Third Phase Can Regulate Up to a 13.5V Output stages out of phase. The part can be configured as a dual n High Efficiency: Up to 92% phase controller plus a single phase controller if needed. n R or DCR Current Sensing The part can also be configured to provide a single 3-phase SENSE n 0.75% 0.8V Output Voltage Accuracy output for even higher output currents. n Phase-Lockable Fixed Frequency 250kHz to 750kHz A wide 4.5V to 24V (28V maximum) input voltage sup- n Supports Pre-Biased Outputs ply range encompasses most battery chemistries and n Dual N-Channel MOSFET Synchronous Drive intermediate bus voltages. Phase 3 can regulate output n Wide V Range: 4.5V to 24V Operation (28V Abs Max) IN voltages up to 13.5V. A constant-frequency current mode n Adjustable Soft-Start Current Ramping or Tracking architecture allows for a phase-lockable frequency up to n Foldback Output Current Limiting 750kHz. n Output Overvoltage Protection n Independent TK/SS pins for each output ramps the output Dual Power Good Output Voltage Monitors n voltages and can be configured for coincident or ratiometric 40-Lead 6mm 6mm QFN Package tracking. Current foldback limits MOSFET heat dissipation L, LT, LTC, LTM, Linear Technology, Burst Mode, Polyphase and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their during short-circuit conditions. The MODE/PLLIN pin respective owners. Protected by U.S. Patents, including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258. selects among Burst Mode operation, pulse-skipping or continuous inductor current modes. TYPICAL APPLICATION High Efficiency Triple 5V/3.3V/1.2V Step-Down Converter V IN 7V TO 24V 22F 4.7F 50V V INTV IN CC TG1 TG2 0.1F PGOOD12 2.2H PGOOD3 SW1,2,3 2.2H BOOST1,2,3 1H SW1 SW2 LTC3853 BG1 BG2 2.2k 1k 2.2k f IN MODE/PLLIN PGND 500kHz 0.1F I LIM FREQ/PLLFLTR 0.1F 0.1F + + SENSE1 SENSE2 SENSE2 V OUT2 V 3.3V FB2 SENSE1 63.4k 5A V 10nF V OUT3 OUT1 1.2V 5V V FB1 100F RUN1,2,3 10k 20k 5A 10k 5A 105k I 6V TH1,2,3 1500pF TG3 220pF V SW3 FB3 100F + SGND BG3 20k 100F + 6V 20k SENSE3 15k 10V SENSE3 TK/SS1,2,3 0.1F 3853fc 1 For more information www.linear.com/LTC3853 + +LTC3853 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Input Supply Voltage (V ) ......................... 28V to 0.3V IN Topside Driver Voltages BOOST1, BOOST2, BOOST3 .................. 34V to 0.3V Switch Voltage (SW1, SW2, SW3) ................ 28V to 5V INTV , RUN1, RUN2, RUN3, PGOOD12, PGOOD3, 40 39 38 37 36 35 34 33 32 31 CC TK/SS2 1 30 BG1 DRV , EXTV , (BOOST1-SW1), CC12 CC TK/SS3 2 29 DRV CC12 (BOOST2-SW2), (BOOST3-SW3) ................. 6V to 0.3V + + + SENSE1 3 28 BG2 SENSE1 , SENSE2 , SENSE1 , SENSE1 4 27 SW2 SENSE2 Voltages .................................... 5.7V to 0.3V + SENSE2 5 26 TG2 + 41 SENSE3 , SENSE3 .................................... 14V to 0.3V SENSE2 6 25 BOOST2 + V .......................................................300A Max I SENSE3 FB2 FB2 7 24 V IN MODE/PLLIN, I ,TK/SS1, SENSE3 8 23 EXTV CC LIM V 9 22 INTV TK/SS2, TK/SS3 Voltages .....................INTV to 0.3V FB1 CC CC I 10 21 BG3 TH1 I , I , I , V , V Voltages ......INTV to 0.3V TH1 TH2 TH3 FB1 FB3 CC 11 12 13 14 15 16 17 18 19 20 INTV Peak Output Current ................................150mA CC Operating Junction Temperature Range (Note 3) E-Grade, I-Grade ................................ 40C to 125C UJ PACKAGE H-Grade ............................................. 40C to 150C 40-LEAD (6mm 6mm) PLASTIC QFN MP-Grade .......................................... 55C to 150C T = 150C, = 33C/W JMAX JA EXPOSED PAD (PIN 41) IS PGND, MUST BE SOLDERED TO PCB Storage Temperature Range .................. 65C to 150C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3853EUJ PBF LTC3853EUJ TRPBF LTC3853UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 125C LTC3853IUJ PBF LTC3853IUJ TRPBF LTC3853UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 125C LTC3853HUJ PBF LTC3853HUJ TRPBF LTC3853UJ 40-Lead (6mm 6mm) Plastic QFN 40C to 150C LTC3853MPUJ PBF LTC3853MPUJ TRPBF LTC3853UJ 40-Lead (6mm 6mm) Plastic QFN 55C to 150C 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: