POWER LOSS (mW) LTC3835-1 Low I Synchronous Q Step-Down Controller FEATURES DESCRIPTION n Wide Output Voltage Range: 0.8V V 10V The LTC 3835-1 is a high performance step-down switch- OUT n Low Operating I : 80A ing regulator controller that drives an all N-channel synchro- Q n OPTI-LOOP Compensation Minimizes C nous power MOSFET stage. A constant-frequency current OUT n 1% Output Voltage Accuracy mode architecture allows a phase-lockable frequency of n Wide V Range: 4V to 36V Operation up to 650kHz. IN n Phase-Lockable Fixed Frequency 140kHz to 650kHz The 80A no-load quiescent current extends operating n Dual N-Channel MOSFET Synchronous Drive life in battery powered systems. OPTI-LOOP compensa- n Very Low Dropout Operation: 99% Duty Cycle tion allows the transient response to be optimized over n Adjustable Output Voltage Soft-Start or Tracking a wide range of output capacitance and ESR values. The n Output Current Foldback Limiting LTC3835-1 features a precision 0.8V reference and a power n Output Overvoltage Protection good output indicator. The 4V to 36V input supply range n Low Shutdown I : 10A Q encompasses a wide range of battery chemistries. n Selectable Continuous, Pulse-Skipping or The TRACK/SS pin ramps the output voltage during start- Burst Mode Operation at Light Loads n up. Current foldback limits MOSFET heat dissipation during Small 16-Lead Narrow SSOP or 3mm 5mm short-circuit conditions. DFN Package Comparison of LTC3835 and LTC3835-1 APPLICATIONS CLKOUT/ PART PHASMD EXTV PGOOD PACKAGES CC n Automotive Systems LTC3835 YES YES YES FE20/4 5 QFN n Telecom Systems LTC3835-1 NO NO NO GN16/3 5 DFN n Battery-Operated Digital Devices L, LT, LTC, LTM, Burst Mode, and OPTI-LOOP are registered trademarks of Linear n Distributed DC Power Systems Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5408150, 5481178, 5705919, 5929620, 6304066, 6498466, 6580258, 6611131. TYPICAL APPLICATION High Ef ciency Step-Down Converter Ef ciency and Power Loss V IN vs Load Current PLLLPF V IN 4V TO 36V 100000 10F 100 RUN TG 0.01F V = 12V V = 3.3V IN OUT 90 0.22F TRACK/SS EFFICIENCY 10000 80 BOOST 3.3H 0.012 V OUT I TH 70 SW 3.3V 1000 330pF LTC3835-1 5A 60 100pF 33k 50 100 150F SGND INTV CC 40 POWER LOSS 10 4.7F PLLIN/MODE 30 20k 20 V BG FB 1 10 SENSE 62.5k 0 0.1 + SENSE PGND 0.001 0.01 0.1 1 10 100 1000 10000 LOAD CURRENT (mA) 38351 TA01b 38351 TA01 38351fc 1 EFFICIENCY (%)LTC3835-1 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage (V ) ......................... 36V to 0.3V INTV Peak Output Current ................................. 50mA IN CC Top Side Driver Voltage (BOOST) ............... 42V to 0.3V Operating Temperature Range (Note 2).... 40C to 85C Switch Voltage (SW) ..................................... 36V to 5V Junction Temperature (Note 3) ............................. 125C INTV , (BOOST-SW) ............................... 8.5V to 0.3V Storage Temperature Range CC RUN, TRACK/SS ......................................... 7V to 0.3V GN Package ....................................... 65C to 150C + SENSE , SENSE Voltages ........................ 11V to 0.3V Storage Temperature Range PLLIN/MODE, PLLLPF .........................INTVCC to 0.3V DHC Package .................................... 65C to 125C I , V Voltages ...................................... 2.7V to 0.3V Lead Temperature (GN Package, Soldering, 10 sec) .... 300C TH FB Peak Output Current <10s (TG, BG) ..........................3A PIN CONFIGURATION TOP VIEW TOP VIEW PLLLPF 1 16 PLLIN/MODE PLLLPF 1 PLLIN/MODE 16 + I 2 15 SENSE TH + I 2 SENSE 15 TH TRACK/SS 3 14 SENSE TRACK/SS 3 SENSE 14 V 4 13 RUN FB 17 V 4 RUN 13 FB SGND 5 12 BOOST SGND 5 BOOST 12 PGND 6 11 TG PGND 6 TG 11 BG 7 10 SW BG 7 SW 10 INTV 8 9 V CC IN INTV 8 V 9 CC IN DHC PACKAGE GN PACKAGE 16-Pin (5mm 3mm) PLASTIC DFNs 16-LEAD PLASTIC SSOP T = 125C, = 43.5C/W JMAX JA T = 150C, = 90C/W JMAX JA EXPOSED PAD (PIN 17) IS SGND MUST BE SOLDERED TO PCB ORDER INFORMATION (Note 2) LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3835EDHC-1 PBF LTC3835EDHC-1 TRPBF 38351 16-Lead (5mm 3mm) Plastic DFN 40C to 85C LTC3835IDHC-1 PBF LTC3835IDHC-1 TRPBF 38351 16-Lead (5mm 3mm) Plastic DFN 40C to 85C LTC3835EGN-1 PBF LTC3835EGN-1 TRPBF 38351 16-Lead Plastic SSOP 40C to 85C LTC3835IGN-1 PBF LTC3835IGN-1 TRPBF 38351 16-Lead Plastic SSOP 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3835EDHC-1 LTC3835EDHC-1 TR 38351 40C to 85C 16-Lead (5mm 3mm) Plastic DFN LTC3835IDHC-1 LTC3835IDHC-1 TR 38351 40C to 85C 16-Lead (5mm 3mm) Plastic DFN LTC3835EGN-1 LTC3835EGN-1 TR 38351 16-Lead Plastic SSOP 40C to 85C LTC3835IGN-1 LTC3835IGN-1 TR 38351 16-Lead Plastic SSOP 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. For more information on lead free part marking, go to: