LTC3127 1A Buck-Boost DC/DC Converter with Programmable Input Current Limit Fae Tseru Dpircse Tnoi n Programmable (0.2A to 1A) 4% Accurate Average The LTC 3127 is a wide V range, highly efficient, 1.35MHz IN Input Current Limit fixed frequency buck-boost DC/DC converter that operates n Regulated Output with Input Voltages Above, from input voltages above, below or equal to the output Below or Equal to the Output voltage. The LTC3127 features programmable average n 1.8V to 5.5V (Input) and 1.8V to 5.25V (Output) input current limit, making it ideal for power-limited input Voltage Range sources. The input current limit is programmed with a n 0.6A Continuous Output Current: V > 1.8V single resistor and is accurate from 0.2A to 1A of average IN n 1A Continuous Output Current: V > 3V input current. IN n Single Inductor The topology incorporated provides a continuous n Synchronous Rectification: Up to 96% Efficiency transfer function through all operating modes. Other n Burst Mode Operation: I = 35A (Pin Selectable) Q features include <1A shutdown current, pin-selectable n Output Disconnect in Shutdown Burst Mode operation and thermal overload protection. n <1A Shutdown Current The LTC3127 is housed in thermally enhanced 10-lead n Small, Thermally Enhanced 10-Lead (3mm 3mm (3mm 3mm 0.75mm) DFN packages and 12-lead 0.75mm) DFN and 12-Lead MSOP Packages MSOP packages. L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks a acilpp Tsnoi and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n USB Powered GSM Modems n Supercap Charger n Handheld Test Instruments n PC Card Modems n Wireless Terminals T lacipy a acilpp Tnoi USB or Li-Ion (500mA Maximum Input Current) to 3.3V Efficiency vs V IN L1 100 300mA LOAD 4.7H 90 SW1 SW2 USB OR Li-Ion V 1A LOAD V OUT V IN OUT 2.9V to 5.5V 3.3V 80 MODE 320k SHDN FB OFF ON 2.2mF 70 PROG V C 10F SGND PGND 182k 60 499k 32.4k V = 3.3V 100pF OUT L = 4.7H F = 1.35MHz 3127 TA01 50 2.5 3 3.5 4 4.5 5 5.5 L1: COILCRAFT XPL4020-472ML V (V) IN 3127 TA01a 3127f EFFICIENCY (%)LTC3127 (Note 1) a ulosb T e Mixa Mu M r a Tsgni V , V Voltage .......................................... 0.3 to 6V PROG Voltage ................................................ 0.3 to 6V IN OUT SW1, SW2 DC Voltage ................................... 0.3 to 6V Operating Junction Temperature Range SW1, SW2 Pulsed (<100ns) Voltage .............. 0.3 to 7V (Note 2) ....................................................40C to 85C MODE, FB, V Voltage .................................... 0.3 to 6V Maximum Junction Temperature (Note 5) ........... 125C C SHDN Voltage ............................................... 0.3 to 6V Storage Temperature Range ..................65C to 125C p ni c no Farugi Tnoi TOP VIEW TOP VIEW SW1 1 10 SW2 PGND 1 12 PGND SW1 2 11 SW2 V 2 9 V IN OUT 13 11 V 3 10 V IN OUT SHDN 3 8 V C PGND PGND SHDN 4 9 V C MODE 4 7 FB 5 MODE 8 FB PROG 5 6 SGND 6 PROG 7 SGND MSE PACKAGE DD PACKAGE 12-LEAD PLASTIC MSOP 10-LEAD (3mm s 3mm) PLASTIC DFN T = 125C, = 40C/W (NOTE 6) JMAX JA T = 125C, = 43C/W (NOTE 6) JMAX JA EXPOSED PAD (PIN 11) IS PGND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 11) IS PGND, MUST BE SOLDERED TO PCB ro D re ni Fro Ma Tnoi LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3127EDD PBF LTC3127EDD TRPBF LDYD 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3127EMSE PBF LTC3127EMSE TRPBF 3127 12-Lead Plastic MSOP 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: