POWER LOSS (W) LTC3409 600mA Low V Buck IN Regulator in 3mm 3mm DFN FEATURES DESCRIPTION 1.6V to 5.5V Input Voltage Range The LTC 3409 is a high ef ciency, monolithic synchronous Internal Soft-Start buck regulator using a constant frequency, current mode Selectable 1.7MHz or 2.6MHz Constant Frequency architecture. The output voltage is adjusted via an external Operation resistor divider. Internal Oscillator can be Synchronizable to an Fixed switching frequencies of 1.7MHz and 2.6MHz are External Clock, 1MHz to 3MHz Range supported. Alternatively, an internal PLL will synchronize High Ef ciency: Up to 95% to an external clock in the frequency range of 1MHz to Very Low Quiescent Current: Only 65A During 3MHz. This range of switching frequencies allows the Burst Mode Operation use of small surface mount inductors and capacitors, 600mA Output Current (V = 1.8V, V = 1.2V) IN OUT including ceramics. 750mA Peak Inductor Current Supply current during Burst Mode operation is only No Schottky Diode Required 65A dropping to <1A in shutdown. The 1.6V to 5.5V Low Dropout Operation: 100% Duty Cycle input voltage range makes the LTC3409 ideally suited 0.613V Reference Voltage for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd Stable with Ceramic Capacitors or NiMH battery-powered applications. 100% duty cycle Shutdown Mode Draws <1A Supply Current capability provides low dropout operation, extending bat- Current Mode Operation for Excellent Line and Load tery life in portable systems. Burst Mode operation can be Transient Response user-enabled, increasing ef ciency at light loads, further Overtemperature Protection extending battery life. Available in a Low Pro le (0.75mm) 8-Lead (3mm 3mm) DFN Package The internal synchronous switch increases ef ciency and eliminates the need for an external Schottky diode. Internal soft-start offers controlled output voltage rise time at start- APPLICATIONS up without the need for external components. Cellular Phones , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Digital Cameras Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, MP3 Players 6498466, 6611131. Burst Mode Ef ciency, 1.8V TYPICAL APPLICATION OUT 100 1.0 2.5V , BURST 90 IN High Ef ciency Step-Down Converter 80 0.1 4.2V , BURST IN 70 3.6V , BURST IN LTC3409 2.2H* 60 V V IN OUT V SW IN 1.8V TO 5.5V 1.8V 50 0.01 10pF 4.7F 10F RUN CER 40 CER MODE V FB POWER LOST 30 255k 3.6V , BURST 133k IN 0.001 SYNC GND 20 10 *SUMIDA CDRH2D18/LD 3409 TA01 0 0.0001 0.1 1 10 100 1000 3409 TA01b LOAD CURRENT (mA) 3409fc 1 EFFICIENCY (%)LTC3409 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Input Supply Voltage ................................... 0.3V to 6V RUN, V , MODE, SYNC Voltages . 0.3V to (V + 0.3V) V 1 8 SYNC FB FB IN GND 2 7 RUN SW Voltage ................................... 0.3V to (V + 0.3V) IN 9 V SW 3 6 IN Operating Temperature Range (Note 2) .. 40C to 85C V 4 5 MODE IN Junction Temperature (Note 3) ........................... 125C Storage Temperature Range .................. 65C to 125C DD PACKAGE 8-LEAD (3mm 3mm) PLASTIC DFN T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3409EDD PBF LTC3409EDD TRPBF LBNM 8-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3409IDD PBF LTC3409IDD TRPBF LBNM 8-Lead (3mm 3mm) Plastic DFN 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *Temperature grades are identi ed by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: