POWER LOSS (mW) LTC3561 1A, 4MHz, Synchronous Step-Down DC/DC Converter FEATURES DESCRIPTIO Uses Tiny Capacitors and Inductor The LTC 3561 is a constant-frequency, synchronous, High Frequency Operation: Up to 4MHz step-down DC/DC converter. Intended for medium power High Switch Current: 1.4A applications, it operates from a 2.63V to 5.5V input voltage Low R Internal Switches: 0.110 range and has a user configurable operating frequency up DS(ON) High Efficiency: Up to 95% to 4MHz, allowing the use of tiny, low cost capacitors and V : 2.63V to 5.5V inductors 2mm or less in height. The output voltage is IN Stable with Ceramic Capacitors adjustable from 0.8V to 5V. Internal synchronous 0.11 Current Mode Operation for Excellent Line power switches with 1.4A peak current ratings provide and Load Transient Response high efficiency. The LTC3561s current mode architecture Short-Circuit Protected and external compensation allow the transient response Low Dropout Operation: 100% Duty Cycle to be optimized over a wide range of loads and output Low Shutdown Current: I 1A capacitors. Q Low Quiescent Current: 240A To further maximize battery life, the P-channel MOSFET is Output Voltages from 0.8V to 5V turned on continuously in dropout (100% duty cycle). The Low Noise Pulse-Skipping Operation no-load quiescent current is only 240A. In shutdown, the Small 8-Pin DFN Package device draws <1A. U , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. APPLICATIO S All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6127815, 6304066, 6498466, 6580258, 6611131. Wireless LAN Power Notebook Computers Digital Cameras Cellular Phones Board Mounted Power Supplies TYPICAL APPLICATIO Step-Down 2.5V/1A Regulator Efficiency and Power Loss vs Load Current V IN 100 1000 2.63V TO 5.5V 95 EFFICIENCY 22F 90 PV IN 85 100 SV 80 IN 2.2H LTC3561 V OUT 75 I SW TH POWER LOSS 2.5V/1A 887k 70 22F SHDN/R V T FB 10 13k 65 SGND PGND 60 324k 412k V = 3.3V IN 1000pF V = 2.5V 55 OUT f = 1MHz O 1 3561 F01 50 NOTE: IN DROPOUT, THE OUTPUT TRACKS 10 100 1000 THE INPUT VOLTAGE. LOAD CURRENT (mA) 3561 TA01 3561f 1 EFFICIENCY (%) U ULTC3561 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW PV , SV Voltages .....................................0.3V to 6V IN IN V , SHDN/R Voltages ................ 0.3V to (V + 0.3V) FB T IN SHDN/R 1 8 I T TH I Voltage ................................................0.3V to 1.4V TH SGND 2 7 V FB 9 SW Voltage ................................... 0.3V to (V + 0.3V) IN SW 3 6 SV IN Operating Ambient Temperature Range PGND PV 4 5 IN (Note 2) .................................................. 40C to 85C Junction Temperature (Notes 5, 8) ....................... 125C DD PACKAGE 8-LEAD (3mm 3mm) PLASTIC DFN Storage Temperature Range ................. 65C to 125C T = 125C, = 43C/W, = 3C/W JMAX JA JC EXPOSED PAD (PIN 9) MUST BE SOLDERED TO GROUND ORDER PART NUMBER DD PART MARKING LTC3561EDD LCJJ Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: