POWER LOSS (W) LTC3561A 1A, 4MHz, Synchronous Step-Down DC/DC Converter FEATURES DESCRIPTION Uses Tiny Capacitors and Inductor The LTC 3561A is a constant frequency, synchronous High Frequency Operation: Up to 4MHz step-down DC/DC converter. Intended for medium power Low R Internal Switches: 0.15 applications, it operates from a 2.5V to 5.5V input voltage DS(ON) High Ef ciency: Up to 96% range and has a user con gurable operating frequency up Stable with Ceramic Capacitors to 4MHz, allowing the use of tiny, low cost capacitors and Current Mode Operation for Excellent Line inductors 1mm or less in height. The output voltage is and Load Transient Response adjustable from 0.8V to 5.5V. Internal synchronous power Short-Circuit Protected switches provide high ef ciency. The LTC3561As current Low Dropout Operation: 100% Duty Cycle mode architecture and external compensation allow the Low Shutdown Current: I 1A transient response to be optimized over a wide range of Q Low Quiescent Current: 330A loads and output capacitors. Output Voltages from 0.8V to 5V To further maximize battery life, the P-channel MOSFET V : 2.5V to 5.5V IN is turned on continuously in dropout (100% duty cycle). Small 8-Lead 3mm 3mm DFN Package In shutdown, the device draws <1A. , LT, LTC and LTM are registered trademarks of Linear Technology APPLICATIONS Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6498466, 6611131. Notebook Computers Digital Cameras Cellular Phones Handheld Instruments Board Mounted Power Supplies TYPICAL APPLICATION Step-Down 2.5V/1A Regulator Ef ciency and Power Loss vs Output Current 100 1 V IN 2.5V TO 5.5V 90 80 10F 0.1 PV IN 70 SV IN 2.2H V OUT 60 SW 2.5V 50 0.01 22pF 1A LTC3561A 22F 40 I V = 2.5V TH OUT 249k 30 f = 1MHz 0.001 O SHDN/R V T FB 16.9k 20 V = 2.7V IN SGND PGND V = 3.6V IN 10 549k 118k 680pF V = 4.2V IN 0 0.0001 110 100 1000 10000 3561a TA01a OUTPUT CURRENT (mA) 3561A TA01b 3561af 1 EFFICIENCY (%)LTC3561A ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW PV , SV Voltages ..................................... 0.3V to 6V IN IN V , I , SHDN/R Voltages ..........0.3V to (V + 0.3V) FB TH T IN SHDN/R 1 8 I T TH SW Voltage ..................................0.3V to (V + 0.3V) IN SGND 2 7 V FB 9 Operating Junction Temperature Range SW 3 6 SV IN (Notes 2, 5, 8) ........................................ 40C to 125C PGND 4 5 PV IN Storage Temperature Range ................... 65C to 125C Lead Temperature (Soldering, 10 sec) .................. 300C DD PACKAGE 8-LEAD (3mm 3mm) PLASTIC DFNs T = 125C, = 43C/W, = 3C/W JMAX JA JC EXPOSED PAD (PIN 9) IS SGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3561AEDD PBF LTC3561AEDD TRPBF LDKB 40C to 125C 8-Lead (3mm 3mm) Plastic DFN LTC3561AIDD PBF LTC3561AIDD TRPBF LDKB 40C to 125C 8-Lead (3mm 3mm) Plastic DFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. For more information on lead free part marking, go to: