LTC3703-5 60V Synchronous Switching Regulator Controller FEATURES DESCRIPTIO High Voltage Operation: Up to 60V The LTC 3703-5 is a synchronous step-down switching Large 1 Gate Drivers (with 5V Supply) regulator controller that can directly step-down voltages No Current Sense Resistor Required from up to 60V input, making it ideal for telecom and au- Step-Up or Step-Down DC/DC Converter tomotive applications. The LTC3703-5 drives external logic Dual N-Channel MOSFET Synchronous Drive level N-channel MOSFETs using a constant frequency (up Excellent Line and Load Transient Response to 600kHz), voltage mode architecture. Programmable Constant Frequency: 100kHz to A precise internal reference provides 1% DC accuracy. A 600kHz high bandwidth error amplifier and patented* line feed 1% Reference Accuracy forward compensation provide very fast line and load Synchronizable up to 600kHz transient response. Strong 1 gate drivers allow the Selectable Pulse Skip Mode Operation LTC3703-5 to drive multiple MOSFETs for higher current Low Shutdown Current: 25A Typ applications. The operating frequency is user program- Programmable Current Limit mable from 100kHz to 600kHz and can also be synchro- Undervoltage Lockout nized to an external clock for noise-sensitive applications. Programmable Soft-Start Current limit is programmable with an external resistor 16-Pin Narrow SSOP and 28-Pin SSOP Packages and utilizes the voltage drop across the synchronous U MOSFET to eliminate the need for a current sense resistor. APPLICATIO S For applications requiring up to 100V operation, refer to 48V Telecom and Base Station Power Supplies the LTC3703 data sheet. Networking Equipment, Servers PARAMETER LTC3703-5 LTC3703 Automotive and Industrial Control Maximum V 60V 100V IN MOSFET Gate Drive 4.5V to 15V 9.3V to 15V , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. + V UV 3.7V 8.7V CC *U.S. Patent Numbers: 5408150, 5055767, 6677210, 5847554, 5481178, 6304066, 6580258 V UV 3.1V 6.2V Others Pending. CC TYPICAL APPLICATIO High Efficiency High Voltage Step-Down Converter V CC 5V Efficiency vs Load Current + V IN 100 22F 6V TO 60V MMDL770T1 MODE/SYNC V V = 12V IN IN + V = 24V IN 22F 30k 95 2 FSET BOOST Si7850DP 10k COMP TG V = 42V IN 0.1F 1000pF 470pF LTC3703-5 90 8H FB SW V OUT 12k 5V 21.5k I V 5A 1% MAX CC 10 + 270F 85 16V INV DRV CC Si7850DP 0.1F RUN/SS BG D1 80 10F MBR1100 0 1 2 3 4 5 100 113k GND BGRTN 1% LOAD CURRENT (A) 1F 37053 TA04b 2200pF 37035 TA04 37035fa 1 EFFICIENCY (%) U ULTC3703-5 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltages MODE/SYNC, INV Voltages....................... 0.3V to 15V V , DRV .......................................... 0.3V to 15V f , FB, I , COMP Voltages ................... 0.3V to 3V CC CC SET MAX (DRV BGRTN), (BOOST SW) ...... 0.3V to 15V Driver Outputs CC BOOST (Continuous) ............................ 0.3V to 85V TG ................................ SW 0.3V to BOOST + 0.3V BOOST (400ms) ................................... 0.3V to 95V BG ........................... BGRTN 0.3V to DRV + 0.3V CC BGRTN ...................................................... 5V to 0V Peak Output Current <10s BG,TG ............................ 5A V Voltage (Continuous).......................... 0.3V to 70V Operating Temperature Range (Note 2) IN V Voltage (400ms) ................................. 0.3V to 80V LTC3703E-5 ........................................ 40C to 85C IN SW Voltage (Continuous) ............................ 1V to 70V LTC3703I-5 ....................................... 40C to 125C SW Voltage (400ms) ................................... 1V to 80V Junction Temperature (Notes 3, 7) ....................... 125C Run/SS Voltage .......................................... 0.3V to 5V Storage Temperature Range ................. 65C to 150C Lead Temperature (Soldering, 10 sec.)................. 300C UUW PACKAGE/ORDER I FOR ATIO TOP VIEW ORDER PART ORDER PART V 1 28 NUMBER BOOST NUMBER IN NC 2 27 TOP VIEW TG NC 3 26 LTC3703EGN-5 SW LTC3703EG-5 MODE/SYNC 1 16 V IN NC 4 25 NC LTC3703IGN-5 LTC3703IG-5 f 2 15 B00ST SET NC 5 24 NC 3 COMP 14 TG MODE/SYNC 6 23 NC FB 4 13 f 7 22 SW NC SET COMP 8 21 V I 5 12 CC V MAX CC FB 9 20 DRV CC 6 11 INV DRV CC GN PART I 10 19 BG MAX RUN/SS 7 10 BG MARKING INV 11 18 NC GND 8 9 BGRTN NC 12 17 NC 37035 RUN/SS 13 16 NC GN PACKAGE GND 14 15 16-LEAD NARROW PLASTIC SSOP 3703I5 BGRTN T = 125C, = 110C/W JMAX JA G PACKAGE 28-LEAD PLASTIC SSOP T = 125C, = 100C/W JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = DRV = V = V = 5V, V = V = V = A CC CC BOOST IN MODE/SYNC INV SW BGRTN = 0V, RUN/SS = I = open, R = 25k, unless otherwise specified. MAX SET SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V , DRV V , DRV Supply Voltage 4.1 15 V CC CC CC CC V V Pin Voltage 60 V IN IN I V Supply Current V = 0V 1.7 2.5 mA CC CC FB RUN/SS = 0V 25 40 A I DRV Supply Current (Note 5) 0 5 A DRVCC CC RUN/SS = 0V 0 5 A I BOOST Supply Current (Note 5) 360 500 A BOOST RUN/SS = 0V 0 5 A 37035fa 2 U WWW