POWER LOSS (mW) LTC3638 High Efficiency, 140V 250mA Step-Down Regulator FEATURES DESCRIPTION n Wide Operating Input Voltage Range: 4V to 140V The LTC 3638 is a high efficiency step-down DC/DC n Internal Low Resistance Power MOSFET regulator with internal power switch that draws only 12A n No Compensation Required typical DC supply current while maintaining a regulated n Adjustable 20mA to 250mA Maximum Output output voltage at no load. Current The LTC3638 can supply up to 250mA 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 and for reduc- n Wide Output Range: 0.8V to V IN ing output ripple and component size. The LTC3638s n 0.8V 1% Feedback Voltage Reference combination of Burst Mode operation, integrated power n Precise RUN Pin Threshold switch, low quiescent current, and programmable peak n Internal or External Soft-Start current limit provides high efficiency over a broad range n Programmable 1.8V, 3.3V, 5V or Adjustable Output of load currents. n Few External Components Required n With its wide input range of 4V to 140V and programmable Programmable Input Overvoltage Lockout n overvoltage lockout, the LTC3638 is a robust regulator Thermally Enhanced High Voltage MSOP Package suited for regulating from a wide variety of power sources. Additionally, the LTC3638 includes a precise run threshold APPLICATIONS and soft-start feature to guarantee that the power system n Industrial Control Supplies start-up is well-controlled in any environment. A feedback n Medical Devices comparator output enables multiple LTC3638s to be con- n Distributed Power Systems nected in parallel for higher current applications. n Portable Instruments The LTC3638 is available in a thermally enhanced high n Battery-Operated Devices voltage-capable 16-lead MSE package with four missing pins. n Avionics L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n Automotive of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Efficiency and Power Loss vs Load Current 100 EFFICIENCY 5V to 140V Input to 5V Output, 250mA Step-Down Regulator 90 80 L1 220H 70 V = 12V IN V V IN OUT V SW V = 48V IN IN 5V TO 140V 5V 60 1000 V = 140V IN LTC3638 250mA 50 V RUN C FB IN 1F 40 100 250V OVLO SS C OUT 30 V V PRG2 PRG1 22F 20 10 GND POWER LOSS 10 3638 TA01a 0 1 0.1 1 10 100 1000 LOAD CURRENT (mA) 3638 TA01b 3638fa 1 For more information www.linear.com/LTC3638 EFFICIENCY (%)LTC3638 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V Supply Voltage ................................... 0.3V to 140V IN SW 1 16 GND RUN Voltage............................................. 0.3V to 140V V 3 14 RUN IN 17 SS, FBO, OVLO, I Voltages ...................... 0.3V to 6V SET FBO 5 GND 12 OVLO 6 V 11 I V , V , V Voltages ......................... 0.3V to 6V PRG2 SET FB PRG1 PRG2 V 7 10 SS PRG1 8 Operating Junction Temperature Range (Notes 2, 3, 4) GND 9 V FB MSE PACKAGE LTC3638E, LTC3638I ......................... 40C to 125C VARIATION: MSE16 (12) LTC3638H .......................................... 40C to 150C 16-LEAD PLASTIC MSOP T = 150C, = 40C/W, = 10C/W JMAX JA JC LTC3638MP ....................................... 55C to 150C EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB Storage Temperature Range .................. 65C to 150C Lead Temperature (Soldering, 10 sec) ...................300C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3638EMSE PBF LTC3638EMSE TRPBF 3638 16-Lead Plastic MSOP 40C to 125C LTC3638IMSE PBF LTC3638IMSE TRPBF 3638 16-Lead Plastic MSOP 40C to 125C LTC3638HMSE PBF LTC3638HMSE TRPBF 3638 16-Lead Plastic MSOP 40C to 150C LTC3638MPMSE PBF LTC3638MPMSE TRPBF 3638 16-Lead Plastic MSOP 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.Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: