POWER LOSS (W) LTC3122 15V, 2.5A Synchronous Step-Up DC/DC Converter with Output Disconnect Fea T Descrip T n V Range: 1.8V to 5.5V, 500mV After Start-Up The LTC 3122 is a synchronous step-up DC/DC converter IN n Output Voltage Range: 2.2V to 15V with true output disconnect and inrush current limiting. The n 800mA Output Current for V = 5V and V = 12V 2.5A current limit along with the ability to program output IN OUT n Output Disconnects from Input When Shut Down voltages up to 15V makes the LTC3122 well suited for a n Synchronous Rectification: Up to 95% Efficiency variety of demanding applications. Once started, opera- n Inrush Current Limit tion will continue with inputs down to 500mV, extending n Up to 3MHz Adjustable Switching Frequency runtime in many applications. Synchronizable to External Clock The LTC3122 features output disconnect in shutdown, n Selectable Burst Mode Operation: 25A I Q dramatically reducing input power drain and enabling n Output Overvoltage Protection V to completely discharge. Adjustable PWM switching OUT n Soft-Start from 100kHz to 3MHz optimizes applications for highest n <1A I in Shutdown Q efficiency or smallest solution footprint. The oscillator n 12-Lead, 3mm 4mm 0.75mm Thermally can also be synchronized to an external clock for noise Enhanced DFN and MSOP Packages sensitive applications. Selectable Burst Mode operation reduces quiescent current to 25A, ensuring high efficiency a T across the entire load range. An internal soft-start limits inrush current during start-up. n RF Power n Piezo Actuators Other features include a <1A shutdown current and ro- n Small DC Motors bust protection under short-circuit, thermal overload, and n 12V Analog Rail From Battery, 5V, or Backup Capacitor output overvoltage conditions. The LTC3122 is offered in both a low profile 12-lead (3mm 4mm 0.75 mm) DFN L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the package and a 12-lead thermally enhanced MSOP package. property of their respective owners. Typical a T 5V to 12V Synchronous Boost Converter with Output Disconnect Efficiency Curve 100 10 3.3H V IN Burst Mode 5V 90 OPERATION SW 80 V OUT V V 12V IN OUT 70 1 800mA LTC3122 PWM SD OFF ON 100nF 60 4.7F BURST PWM PWM/SYNC CAP 50 1.02M 40 RT FB 22F 0.1 30 PWM POWER LOSS V V 113k CC C 20 SGND PGND 210k 57.6k 10 10pF 4.7F 390pF 0 0.01 0.01 0.1 1 10 100 1000 LOAD CURRENT (mA) 3122 TA01b 3122 TA01a 3122fa 1 For more information www.linear.com/LTC3122 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3122 a Te Maxi Mu M r a T (Note 1) V Voltage .................................................. 0.3V to 6V All Other Pins ............................................... 0.3V to 6V IN V Voltage ............................................ 0.3V to 18V Operating Junction Temperature Range (Notes 3, 4) OUT SW Voltage (Note 2) .................................. 0.3V to 18V LTC3122E/LTC3122I .......................... 40C to 125C SW Voltage (Pulsed < 100ns) (Note 2) ....... 0.3V to 19V LTC3122H .......................................... 40C to 150C V , RT Voltage .......................................... 0.3V to V Storage Temperature Range .................. 65C to 150C C CC CAP Voltage MSE Lead Temperature (Soldering, 10sec) ...........300C V < 5.7V ............................0.3V to (V + 0.3V) OUT OUT 5.7V V 11.7V...... (V 6V) to (V + 0.3V) OUT OUT OUT V > 11.7V .................................(V 6V) to 12V OUT OUT p in c F T TOP VIEW TOP VIEW SW 1 12 CAP SW 1 12 CAP PGND 2 11 V OUT PGND 2 11 V OUT V 3 10 SGND IN 13 V 3 13 10 SGND IN PGND PGND PWM/SYNC 4 9 SD PWM/SYNC 4 9 SD 5 V 8 FB CC V 5 8 FB CC RT 6 7 V C RT 6 7 V C MSE PACKAGE 12-LEAD PLASTIC MSOP DE PACKAGE T = 150C, = 40C/W (NOTE 5), = 10C/W JMAX JA JC 12-LEAD (4mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 13) IS PGND, T = 125C, = 43C/W (NOTE 5), = 5C/W JMAX JA JC MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE EXPOSED PAD (PIN 13) IS PGND, MUST BE SOLDERED TO PCB FOR RATED THERMAL PERFORMANCE o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3122EDE PBF LTC3122EDE TRPBF 3122 12-Lead (4mm 3mm) Plastic DFN 40C to 125C LTC3122IDE PBF LTC3122IDE TRPBF 3122 12-Lead (4mm 3mm) Plastic DFN 40C to 125C LTC3122EMSE PBF LTC3122EMSE TRPBF 3122 12-Lead Plastic MSOP 40C to 125C LTC3122IMSE PBF LTC3122IMSE TRPBF 3122 12-Lead Plastic MSOP 40C to 125C LTC3122HMSE PBF LTC3122HMSE TRPBF 3122 12-Lead Plastic MSOP 40C 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: