DC413A Analog Devices

LTC3404 1.4MHz High Efficiency Monolithic Synchronous Step-Down Regulator FEATURES DESCRIPTIO High Efficiency: Up to 95% The LTC 3404 is a high efficiency monolithic synchro- Very Low Quiescent Current: Only 10A nous buck regulator using a constant frequency, current During Operation mode architecture. Supply current during operation is 600mA Output Current at V = 3.3V only 10A and drops to < 1A in shutdown. The 2.65V to IN 2.65V to 6V Input Voltage Range 6V input voltage range makes the LTC3404 ideally suited 1.4MHz Constant Frequency Operation for single Li-Ion battery-powered applications. 100% duty No Schottky Diode Required cycle provides low dropout operation, extending battery Low Dropout Operation: 100% Duty Cycle life in portable systems. Synchronizable from 1MHz to 1.7MHz Switching frequency is internally set at 1.4MHz, allowing Selectable Burst Mode Operation or the use of small surface mount inductors and capacitors. Pulse Skipping Mode For noise sensitive applications the LTC3404 can be 0.8V Reference Allows Low Output Voltages externally synchronized from 1MHz to 1.7MHz. Burst Shutdown Mode Draws < 1 A Supply Current Mode operation is inhibited during synchronization or 2% Output Voltage Accuracy when the SYNC/MODE pin is pulled low, preventing low Current Mode Control for Excellent Line and frequency ripple from interfering with audio circuitry. Load Transient Response Overcurrent and Overtemperature Protected The internal synchronous switch increases efficiency and Available in 8-Lead MSOP Package eliminates the need for an external Schottky diode. Low U output voltages are easily supported with the 0.8V feed- APPLICATIO S back reference voltage. The LTC3404 is available in a Cellular Telephones space saving 8-lead MSOP package. Wireless and DSL Modems For higher input voltage (11V abs max) applications, refer Personal Information Appliances to the LTC1877 data sheet. Portable Instruments , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Distributed Power Systems Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Battery-Powered Equipment Efficiency vs Output Load Current TYPICAL APPLICATIO 100 V = 3.6V IN 95 High Efficiency Step-Down Converter 4.7H* V V = 4.2V IN IN 7 5 V 90 OUT 2.65V SYNC SW 3.3V 20pF V = 6V IN TO 6V 6 10F*** V IN CER 22F** 85 LTC3404 1 RUN CER 887k 2 3 80 I V FB TH GND 280k 47pF 4 75 Burst Mode OPERATION 3404 TA01 V = 3.3V OUT L = 4.7H *TOKO D52LC A914BYW-4R7M 70 **TAIYO-YUDEN CERAMIC JMK325BJ226MM 0.1 1 10 100 1000 ***TAIYO-YUDEN CERAMIC LMK325BJ106MN LOAD (mA) V CONNECTED TO V FOR 2.65V < V < 3.3V OUT IN IN 3404 TA02 3404fb 1 EFFICIENCY (%) U ULTC3404 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) Input Supply Voltage (V )...........................0.3V to 7V TOP VIEW IN RUN 1 8 PLL LPF I , PLL LPF Voltage ................................0.3V to 2.7V TH I 2 7 SYNC/MODE TH RUN, V Voltages ...................................... 0.3V to V V 3 6 V FB IN FB IN 5 GND 4 SW SYNC/MODE Voltage .................................. 0.3V to V IN MS8 PACKAGE SW Voltage (DC) .......................... 0.3V to (V + 0.3V) IN 8-LEAD PLASTIC MSOP P-Channel MOSFET Source Current (DC) ........... 800mA T = 125C, = 125C/W JMAX JA N-Channel MOSFET Sink Current (DC) ............... 800mA ORDER PART NUMBER MS8 PART MARKING Peak SW Sink and Source Current ........................ 1.5A LTC3404EMS8 LTKR Operating Temperature Range (Note 2) LTCJR LTC3404IMS8 LTC3404E/LTC3404I ........................... 40C to 85C LTCXG LTC3404MPMS8 LTC3404MP ...................................... 55C to 125C Junction Temperature (Note 3)............................ 125C Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Storage Temperature Range ................. 65C to 150C Lead Free Part Marking: