LTC3899 60V Low I , Triple Q Output, Buck/Buck/Boost Synchronous Controller FEATURES DESCRIPTION n Dual Buck Plus Single Boost Synchronous Controllers The LTC 3899 is a high performance triple output (buck/ n Wide Bias Input Voltage Range: 4.5V to 60V buck/boost) DC/DC switching regulator controller that n Outputs Remain in Regulation Through Cold Crank drives all N-channel synchronous power MOSFET stages. Down to a 2.2V Input Supply Voltage The constant frequency current mode architecture allows n Buck and Boost Output Voltages Up to 60V a phase-lockable frequency of up to 850kHz. The LTC3899 n Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE) operates from a wide 4.5V to 60V input supply range. n No External Bootstrap Diodes Required When biased from the output of the boost converter or n Low Operating I : 29A (One Channel On) another auxiliary supply, the LTC3899 can operate from Q n 100% Duty Cycle for Boost Synchronous MOSFET an input supply as low as 2.2V after start-up. n Phase-Lockable Frequency (75kHz to 850kHz) The gate drive for the LTC3899 can be programmed from n Programmable Fixed Frequency (50kHz to 900kHz) 5V to 10V to allow the use of logic-level or standard-level n Very Low Dropout Operation: 99% Duty Cycle (Bucks) FETs and to maximize efficiency. Internal switches in the n Low Shutdown I : 3.6A Q top gate drivers eliminate the need for external bootstrap n Fixed or Adjustable Boost Output Voltage Saves I Q diodes. The 29A no-load quiescent current extends op- n Small 38-Lead 5mm 7mm QFN and TSSOP Packages erating run time in battery-powered systems. OPTI-LOOP compensation allows the transient response to be optimized APPLICATIONS over a wide range of output capacitance and ESR values. n Automotive Always-On and Start-Stop Systems L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property n Distributed DC Power Systems of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, n 6144194, 6177787, 6580258. Multioutput Buck-Boost Applications TYPICAL APPLICATION High Efficiency Wide Input Range Dual 5V/8.5V Converter Efficiency vs Output Current V OUT3 95 REGULATED AT 10V V = 12V IN 33F WHEN V < 10V IN RUN1, 2, 3 V V = 5V BIAS OUT FOLLOWS V WHEN 94 IN V TG1 Burst Mode OPERATION FB3 V > 10V 0.1F IN TG3 BOOST1 4.9H 93 9m V OUT1 0.1F 5V SW1 BOOST3 5A 1.2H 3m V 92 IN BG1 SW3 2.2V TO 60V LTC3899 33F (START-UP BG3 + SENSE1 ABOVE 5V) 91 SENSE1 357k SENSE3 GATE DRIVE (DRV ) V FB1 CC + 90 SENSE3 5V 68.1k 220F DRV CC 6V INTV CC 89 8V 4.7F 0.1F 10V TG2 88 0.1F 0.01 0.1 1 10 ITH1,2,3 BOOST2 6.5H 15m V OUT2 OUTPUT CURRENT(A) SW2 8.5V 3899 TA01b 3A BG2 DRVSET + SENSE2 SENSE2 649k VPRG3 V FB2 GND 68.1k 68F 3899 TA01a 3899fa 1 For more information www.linear.com/LTC3899 EFFICIENCY (%)LTC3899 ABSOLUTE MAXIMUM RATINGS (Notes 1, 3) PLLIN/MODE, FREQ, DRVSET Voltages ....... 0.3V to 6V Bias Input Supply Voltage (V ) .............. 0.3V to 65V BIAS EXTV Voltage ......................................... 0.3V to 14V Topside Driver Voltages CC ITH1, ITH2, ITH3, V , V Voltages ......... 0.3V to 6V BOOST1, BOOST2, BOOST3 .................. 0.3V to 76V FB1 FB2 V Voltage............................................... 0.3V to 65V Switch Voltage (SW1, SW2, SW3) ................ 5V to 70V FB3 VPRG3, Voltage ........................................... 0.3V to 6V DRV , (BOOST1-SW1), (BOOST2-SW2), CC TRACK/SS1, TRACK/SS2, SS3 Voltages ...... 0.3V to 6V (BOOST3-SW3) ...........................................0.3V to 11V Operating Junction Temperature Range (Note 2) BG1, BG2, BG3, TG1, TG2, TG3 .......................... (Note 8) LTC3899E, LTC3899I ......................... 40C to 125C RUN1, RUN2, RUN3 Voltages ..................... 0.3V to 65V + + LTC3899H .......................................... 40C to 150C SENSE1 , SENSE2 , SENSE1 LTC3899MP ....................................... 55C to 150C SENSE2 Voltages ..................................... 0.3V to 65V + Storage Temperature Range .................. 65C to 150C SENSE3 , SENSE3 Voltages ..................... 0.3V to 65V PIN CONFIGURATION TOP VIEW TOP VIEW ITH1 1 38 VPRG3 V 2 37 TRACK/SS1 FB1 + SENSE1 3 36 TG1 38 37 36 35 34 33 32 SENSE1 4 35 SW1 FREQ 1 31 SW1 FREQ 5 34 BOOST1 PLLIN/MODE 2 30 BOOST1 PLLIN/MODE 6 33 BG1 SS3 3 29 BG1 SS3 7 32 SW3 + SENSE3 4 28 SW3 + SENSE3 8 31 TG3 SENSE3 5 27 TG3 SENSE3 9 30 BOOST3 V 6 26 BOOST3 FB3 39 39 V 10 29 BG3 FB3 GND GND ITH3 7 25 BG3 ITH3 11 28 V BIAS INTV 8 24 V CC BIAS INTV 12 27 EXTV CC CC RUN1 9 23 EXTV CC RUN1 13 26 DRV CC RUN2 10 22 DRV CC RUN2 14 25 BG2 21 RUN3 11 BG2 RUN3 15 24 BOOST2 SENSE2 12 20 BOOST2 13 14 15 16 17 18 19 SENSE2 16 23 SW2 + SENSE2 17 22 TG2 V 18 21 TRACK/SS2 FB2 ITH2 19 20 DRVSET UHF PACKAGE 38-LEAD (5mm 7mm) PLASTIC QFN FE PACKAGE T = 150C, = 34C/W 38-LEAD PLASTIC TSSOP JMAX JA EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB T = 150C, = 25C/W JMAX JA EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB 3899fa 2 For more information www.linear.com/LTC3899 + SENSE2 SENSE1 + V SENSE1 FB2 ITH2 V FB1 DRVSET ITH1 TRACK/SS2 VPRG3 TG2 TRACK/SS1 SW2 TG1