LTC3535 Dual Channel 550mA 1MHz Synchronous Step-Up DC/DC Converter FEATURESDESCRIPTION n Two Independent Step-Up Converters The LTC®3535 is a dual channel, synchronous, fixed fre- n Each Channel Delivers 3.3V at 100mA from a Single quency step-up DC/DC converter with output disconnect. Alkaline/NiMH Cell or 3.3V at 200mA from Two Cells Extended battery life in single AA/AAA powered products n VIN Start-Up Voltage: 680mV is realized with a 680mV start-up voltage and operation n 1.5V to 5.25V VOUT Range down to 500mV once started. n Up to 94% Efficiency A switching frequency of 1MHz minimizes solution foot- n Output Disconnect print by allowing the use of tiny, low profile inductors n 1MHz Fixed Frequency Operation and ceramic capacitors. The current mode PWM design n VIN > VOUT Operation is internally compensated, reducing external parts count. n Integrated Soft-Start The LTC3535 features Burst Mode operation at light load n Current Mode Control with Internal Compensation conditions allowing it to maintain high efficiency over a n Burst Mode® Operation with 9µA IQ Each Channel wide range of load. Anti-ring circuitry reduces EMI by n Internal Synchronous Rectifier damping the inductor in discontinuous mode. Additional n Logic Controlled Shutdown (IQ < 1µA) features include a low shutdown current of under 1µA and n Anti-Ring Control thermal shutdown. n Low Profile (3mm × 3mm × 0.75mm) 12-Lead DFN Package The LTC3535 is housed in a 3mm × 3mm × 0.75mm DFN package. APPLICATIONS L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective n Medical Instruments owners. n Noise Canceling Headphones n Energy Harvesting n Bluetooth Headsets TYPICAL APPLICATION 4.7µH Efficiency vs Load Current 100 SW1 VOUT1 VOUT = 1.8V VIN1 VOUT1 1.8V 90 100mA OFF ON 10µF SHDN1 V 80 VIN OUT2 511k V 0.8V V 10µF OUT2 70 OUT = 3.3V TO 1.5V LTC3535 3.3V 2.2µF 50mA 60 VIN2 FB1 50 OFF ON 1.78M SHDN2 FB2 1M 40 GND SW2 GND EFFICIENCY (%) 30 1M 20 4.7µH 3535 TA01 10 V 0 IN = 1.2V 0.01 0.1 1 10 100 1000 LOAD CURRENT (mA) 3535 TA01b 3535fa 1 Document Outline Features Description Applcations Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts