POWER LOSS (mW) LTC3427 500mA, 1.25MHz Synchronous Step-Up DC/DC Converter in 2mm 2mm DFN Package FEATURES DESCRIPTIO High Efficiency: Up to 94% The LTC 3427 is the industrys first high efficiency, fixed 3.3V at 200mA from Two Alkaline Cells frequency, step-up DC/DC converter with true output 5V at 200mA from a Single Li-Ion Cell disconnect in a 6-lead 2mm 2mm DFN package. Requir- Inrush Current Limiting and Soft-Start ing minimal external components, the LTC3427 operates Output Disconnect in Shutdown from an input voltage as low as 1.8V. The LTC3427 1.8V to 5V V Range contains an internal 0.525 N-channel MOSFET switch IN 1.8V to 5.25V V Range and a 0.575 P-channel MOSFET synchronous rectifier, OUT 1.25MHz Fixed Frequency, Low Noise PWM which enables it to supply 200mA at 3.3V from a 2-cell Internal Synchronous Rectifier alkaline battery input. Logic Controlled Shutdown (<1A) The LTC3427 limits inrush current during start-up and Anti-Ringing Control Minimizes EMI provides a soft-start of V . A switching frequency of OUT Tiny External Components 1.25MHz minimizes solution footprint by allowing the use Short-Circuit Protection of tiny, low profile inductors and ceramic capacitors and Low Profile (0.75mm 2mm 2mm) DFN Package produces very low V ripple. The current mode PWM OUT U design is internally compensated, reducing external parts APPLICATIO S count. Anti-ringing control reduces EMI in discontinuous Handheld Instruments mode operation. The LTC3427 also features low shut- Digital Cameras down current of under 1A and thermal shutdown. Wireless Handsets , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. GPS Receivers Portable Medical Devices MP3 Players TYPICAL APPLICATIO 2.4V to 3.3V Efficiency 2-Cell Alkaline to 3.3V Synchronous Boost Converter 100 1000 4.7H 95 V IN 1.8V TO 3.2V EFFICIENCY + 2-CELL 2.2F 90 ALKALINE V SW IN LTC3427 85 100 V OUT OFF ON SHDN V 3.3V OUT 200mA 80 1000k POWER LOSS 4.7F GND FB 75 604k 70 10 10 100 1000 3427 TA01a LOAD CURRENT (mA) 3427 TA01b 3427fa 1 EFFICIENCY (%) U ULTC3427 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW V , V Voltages ...................................... 0.3V to 6V IN OUT SHDN, FB Voltages ..................................... 0.3V to 6V SW Voltage 6 5 4 DC .......................................................... 0.3V to 6V 7 Pulsed < 100ns ...................................... 0.3V to 7V Operating Temperature Range 1 2 3 (Notes 2, 5) ............................................ 40C to 85C Storage Temperature Range ................ 65C to 125C DC PACKAGE 6-LEAD (2mm 2mm) PLASTIC DFN T = 125C, = 60C/W TO 85C/W JMAX JA EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER DC PART MARKING LTC3427EDC LBSY Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: