POWER LOSS (mW) LTC3527/LTC3527-1 Dual 800mA/400mA, 1.2MHz/2.2MHz Synchronous Step-Up DC/DC Converters FEATURES DESCRIPTION n Dual Synchronous Step-Up DC/DC Converters The LTC 3527/LTC3527-1 are dual high ef ciency, step-up n Delivers 3.3V at 200mA/100mA from one Alkaline/ DC/DC converters in a space saving 16-lead 3mm 3mm NiMH Cell, or 3.3V at 400mA/200mA from Two Cells QFN package. Battery life is maximized with a 700mV start- n V Start-Up Voltage: 700mV up voltage and operation down to 500mV once started. IN n 0.5V to 5V V Range After Start-Up The SHDN and PGOOD pins enable the converters to be IN n 1.6V to 5.25V V Range sequenced or started together. OUT n Output Disconnect in Shutdown The LTC3527/LTC3527-1 limit inrush current during start- n V > V Operation IN OUT up. Selectable 1.2MHz or 2.2MHz operation provides a n 1.2MHz or 2.2MHz Operation choice between the highest ef ciency or smallest solu- n Up to 94% Ef ciency tion footprint. The current mode PWM design is internally n 12A Quiescent Current in Burst Mode Operation compensated reducing external parts count. Burst Mode n Inrush Current Limiting and Soft-Start operation or xed frequency operation is selectable via the n Internal Synchronous Recti ers MODE pin. Anti-ring circuitry reduces EMI in discontinuous n Logic-Controlled Shutdown (< 2A) mode. This device also features thermal shutdown. n Quick V Discharge (LTC3527-1) OUT n True output disconnect allows the output to be completely 16-Lead, 0.75mm 3mm 3mm QFN Package open in shutdown. The LTC3527-1 actively discharges V or V when its respective SHDN goes low. Qui- OUT1 OUT2 APPLICATIONS escent current in shutdown is less than 2A. n MP3/Personal Media Players L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the n Noise Canceling/Bluetooth Headsets property of their respective owners. n Wireless Mice n Portable Medical Instruments TYPICAL APPLICATION Two-Cell Alkaline to 3.3V/1.8V Synchronous Boost Converters 1.2MHz Ef ciency and Power Loss 100 1000 1.6V to 3.2V BURST + 90 EFFICIENCY V IN 4.7F 4.7H 4.7H 80 100 V V V IN1 IN IN2 70 V SW1 SW2 V OUT OUT V V 60 10 3.3V OUT1 OUT2 1.8V 150mA 150mA 1.78M LTC3527 619k 4.7F 15pF 15pF 50 FIXED FREQUENCY FB1 FB2 40 1 1.21M 1M PGOOD1 PGOOD2 ON 30 4.7F SHDN1 SHDN2 POWER OFF 20 0.1 LOSS MODE GND F SEL V = 2.4V IN 10 V = 3.3V BURST OUT1 ON 35271 TA01 0 0.01 OFF 0.01 0.1 1 10 100 1000 LOAD CURRENT (mA) 35271 TA01b 35271fc 1 EFFICIENCY (%)LTC3527/LTC3527-1 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , V , V Voltage .................................0.3V to 6V IN IN1 IN2 SW1, SW2 Voltage (DC) ..............................0.3V to 6V (Pulsed < 100ns) .....................................0.3V to 7V 16 15 14 13 SHDN1, SHDN2, FB1, FB2 Voltage ...............0.3V to 6V SHDN1 1 12 SHDN2 FB1 2 11 FB2 V , V ................................................0.3V to 6V 17 OUT1 OUT2 PGND MODE 3 10 FSEL MODE, FSEL, PGOOD1, PGOOD2 .................0.3V to 6V V V 4 9 IN1 IN2 Operating Temperature (Notes 2, 5) .........40C to 85C 5 6 7 8 Junction Temperature ........................................... 125C Storage Temperature Range ...................65C to 125C UD PACKAGE 16-LEAD (3mm s 3mm) PLASTIC QFN T = 125C, = 68C/W JMAX JA EXPOSED PAD (PIN 17) IS PGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3527EUD PBF LTC3527EUD TRPBF LDDK 40C to 85C 16-Lead (3mm 3mm) Plastic QFN LTC3527EUD-1 PBF LTC3527EUD-1 TRPBF LCXP 40C to 85C 16-Lead (3mm 3mm) Plastic QFN LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3527EUD LTC3527EUD TR LDDK 16-Lead (3mm 3mm) Plastic QFN 40C to 85C LTC3527EUD-1 LTC3527EUD-1 TR LCXP 40C to 85C 16-Lead (3mm 3mm) Plastic QFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. For more information on lead free part marking, go to: