POWER LOSS (mW) LTC3632 High Efficiency, High Voltage 20mA Synchronous Step-Down Converter FEATURES DESCRIPTION n Wide Input Voltage Range: Operation from The LTC 3632 is a high efficiency, high voltage step-down 4.5V to 50V DC/DC converter with internal high side and synchronous n Overvoltage Lockout Provides Protection Up to 60V power switches that draws only 12A typical DC sup- n Internal High Side and Low Side Power Switches ply current at no load while maintaining output voltage n No Compensation Required regulation. n 20mA Output Current The LTC3632 can supply up to 20mA load current and n Low Dropout Operation: 100% Duty Cycle features a programmable peak current limit that provides n Low Quiescent Current: 12A a simple method for optimizing efficiency in lower current n Wide Output Voltage Range: 0.8V to V IN applications. The LTC3632s combination of Burst Mode n 0.8V 1% Feedback Voltage Reference operation, integrated power switches, low quiescent cur- n Adjustable Peak Current Limit rent, and programmable peak current limit provides high n Internal and External Soft-Start efficiency over a broad range of load currents. n Precise RUN Pin Threshold with Adjustable With its wide 4.5V to 50V input range and internal Hysteresis n overvoltage monitor capable of protecting the part through Few External Components Required n 60V surges, the LTC3632 is a robust converter suited for Low Profile (0.75mm) 3mm 3mm DFN and regulating a wide variety of power sources. Additionally, Thermally Enhanced MS8E Packages the LTC3632 includes a precise run threshold and soft-start feature to guarantee that the power system start-up is APPLICATIONS well-controlled in any environment. n 4mA to 20mA Current Loops The LTC3632 is available in the thermally enhanced n Industrial Control Supplies 3mm 3mm DFN and MS8E packages. n Distributed Power Systems n L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks Portable Instruments and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the n Battery-Operated Devices property of their respective owners. n Automotive Power Systems Efficiency and Power Loss vs Load Current TYPICAL APPLICATION 100 1000 5V, 20mA Step-Down Converter 90 EFFICIENCY 80 1mH V OUT V IN V SW 5V IN 5V TO 50V 70 100 20mA LTC3632 1F 10F 1.47M RUN 60 V HYST FB 50 10 I SS SET 280k POWER LOSS GND 40 3632 TA01a 30 1 V = 10V IN V = 48V IN 20 0.1 1 10 LOAD CURRENT (mA) 3632 TA01b 3632fc 1 EFFICIENCY (%)LTC3632 ABSOLUTE MAXIMUM RATINGS (Note 1) V Supply Voltage ..................................... 0.3V to 60V Storage Temperature Range ................... 65C to 150C IN SW Voltage (DC) ............................0.3V to (V + 0.3V) Lead Temperature (Soldering, 10 sec) IN RUN Voltage .............................................. 0.3V to 60V MS8E ................................................................ 300C V , HYST, I , SS Voltages ........................ 0.3V to 6V FB SET Operating Junction Temperature Range (Note 2) .................................................. 40C to 125C PIN CONFIGURATION TOP VIEW TOP VIEW SW 1 8 GND SW 1 8 GND V 2 7 HYST IN V 2 9 7 HYST 9 IN GND GND I 3 6 V I V SET FB 3 6 SET FB 5 RUN SS 4 SS RUN 4 5 MS8E PACKAGE 8-LEAD PLASTIC MSOP DD PACKAGE T = 125C, = 40C/W, = 5-10C/W JMAX JA JC 8-LEAD (3mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 43C/W, = 3C/W JMAX JA JC EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3632EMS8E PBF LTC3632EMS8E TRPBF LTFFZ 8-Lead Plastic MSOP 40C to 125C LTC3632IMS8E PBF LTC3632IMS8E TRPBF LTFFZ 8-Lead Plastic MSOP 40C to 125C LTC3632EDD PBF LTC3632EDD TRPBF LFGB 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3632IDD PBF LTC3632IDD TRPBF LFGB 40C to 125C 8-Lead (3mm 3mm) Plastic DFN 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 non-standard lead based finish parts. For more information on lead free part marking, go to: