POWER LOSS (mW) LTC3422 1.5A, 3MHz Synchronous Step-Up DC/DC Converter with Output Disconnect FEATURES DESCRIPTIO 700mA Continuous/1A Pulsed Output Current The LTC 3422 is a high efficiency, current mode, fixed for Li-Ion to 5V Applications frequency, step-up DC/DC converter with true output Synchronous Rectification: Up to 96% Efficiency disconnect and inrush current limiting. The part is guaran- True Output Disconnect teed to start up from an input voltage of 1V. The device Inrush Current Limiting includes a 0.20 N-channel MOSFET switch and a 0.24 Adjustable Automatic Burst Mode Operation P-channel MOSFET synchronous rectifier. The output Low Noise, Fixed Frequency Operation from voltage, switching frequency, soft-start time, Burst Mode 100kHz to 3MHz threshold and loop compensation are all simply pro- 0.5V to 4.5V Input Range grammed using tiny external passive components. 2.25V to 5.25V Adjustable Output Voltage Quiescent current is only 25A during Burst Mode opera- Guaranteed 1V Start-Up tion, maximizing battery life in portable applications. The Programmable Soft-Start oscillator frequency can be programmed up to 3MHz and Synchronizable Oscillator can be synchronized to an external clock applied to the Low Quiescent Current: 25A SYNC pin. <1A Shutdown Current Other features include 1A shutdown, short-circuit protec- Anti-Ringing Control tion, anti-ringing control, thermal shutdown and current Small (3mm 3mm 0.75mm) Thermally Enhanced limit. The LTC3422 is available in a (3mm 3mm 0.75mm) 10-Pin DFN Package U 10-pin DFN package. APPLICATIO S , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Wireless Handsets Handheld Computers GPS Receivers MP3 Players TYPICAL APPLICATIO 2.4V to 3.3V Efficiency and Power Loss 100 10000 BURST 4.7H 90 V EFFICIENCY IN 1.8V TO 3.2V 80 1000 + 4.7F 2 CELLS V SW IN 70 PWM V OUT EFFICIENCY SYNC V 3.3V 60 100 OUT 22F 600mA 931k 50 LTC3422 40 10 SHDN FB OFF ON PWM POWER 30 V BURST 549k C LOSSES SS R GND 20 BURST 1 1nF T POWER 10 LOSSES 15k 22pF 0.1F 28k 2.2nF 301k f = 1MHz OSC 0 0 0.1 1 10 100 1000 3422 TA01a LOAD CURRENT (mA) 3422 TA01b 3422fa 1 EFFICIENCY (%) U ULTC3422 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW V , V , SYNC Voltages ........................... 0.3V to 6V IN OUT FB, SS, BURST, SHDN Voltages ................ 0.3V to 6V SW 10 V 1 OUT SW Voltage V 2 9 SYNC IN 11 BURST 3 8 R T DC .......................................................... 0.3V to 6V SS 4 7 V C Pulsed < 100ns ...................................... 0.3V to 7V SHDN 5 6 FB Operating Temperature Range DD PACKAGE (Notes 2, 5)............................................. 40C to 85C 10-LEAD (3mm 3mm) PLASTIC DFN Storage Temperature Range ................. 65C to 125C T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER DD PART MARKING LTC3422EDD LBRN Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: