LTC3411 1.25A, 4MHz, Synchronous Step-Down DC/DC Converter FEATURES DESCRIPTION n The LTC 3411 is a constant frequency, synchronous, Small 10-Lead MSOP or DFN Package n step- down DC/DC converter. Intended for medium power Uses Tiny Capacitors and Inductor n applications, it operates from a 2.63V to 5.5V input voltage High Frequency Operation: Up to 4MHz n range and has a user con gurable operating frequency High Switch Current: 1.6A n up to 4MHz, allowing the use of tiny, low cost capacitors Low R Internal Switches: 0.110 DS(ON) n and inductors 2mm or less in height. The output voltage High Ef ciency: Up to 95% n is adjustable from 0.8V to 5V. Internal sychronous 0.11 Stable with Ceramic Capacitors n power switches with 1.6A peak current ratings provide Current Mode Operation for Excellent Line high ef ciency. The LTC3411s current mode architecture and Load Transient Response n and external compensation allow the transient response Short-Circuit Protected n to be optimized over a wide range of loads and output Low Dropout Operation: 100% Duty Cycle n capacitors. Low Shutdown Current: I 1A Q n Low Quiescent Current: 60A The LTC3411 can be con gured for automatic power sav- n Output Voltages from 0.8V to 5V ing Burst Mode operation to reduce gate charge losses n Selectable Burst Mode Operation when the load current drops below the level required for n Synchronizable to External Clock continuous operation. For reduced noise and RF interfer- ence, the SYNC/MODE pin can be con gured to skip pulses APPLICATIONS or provide forced continuous operation. n Notebook Computers To further maximize battery life, the P-channel MOSFET n Digital Cameras is turned on continuously in dropout (100% duty cycle) n Cellular Phones with a low quiescent current of 60A. In shutdown, the n Handheld Instruments device draws <1A. n Board Mounted Power Supplies L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. TYPICAL APPLICATION V IN Ef ciency vs Load Current 2.63V TO 5.5V 100 C1 22F 95 V SYNC/MODE PV IN IN L1 PGOOD SV IN 2.2H V 90 OUT SW 2.5V/1.25A LTC3411 C2 I TH 887k 85 22F SHDN/R V T FB 13k SGND PGND 80 324k 412k 1000pF V = 3.3V IN V = 2.5V 75 OUT f = 1MHz O NOTE: IN DROPOUT, THE OUTPUT TRACKS 3411 F01 Burst Mode OPERATION THE INPUT VOLTAGE 70 C1, C2: TAIYO YUDEN JMK325BJ226MM 1 10 100 1000 L1: TOKO A914BYW-2R2M (D52LC SERIES) LOAD CURRENT (mA) 3411 TA01 Figure 1. Step-Down 2.5V/1.25A Regulator 3411fb 1 EFFICIENCY (%)LTC3411 ABSOLUTE MAXIMUM RATINGS (Note 1) PV , SV Voltages ..................................... 0.3V to 6V Junction Temperature (Notes 5, 8) ....................... 125C IN IN V , I , SHDN/R Voltages ..........0.3V to (V + 0.3V) Storage Temperature Range FB TH T IN SYNC/MODE Voltage .....................0.3V to (V + 0.3V) DD Package ....................................... 65C to 125C IN SW Voltage ..................................0.3V to (V + 0.3V) MS Package ...................................... 65C to 150C IN PGOOD Voltage ........................................... 0.3V to 6V Lead Temperature (Soldering, 10 sec) .................. 300C Operating Temperature Range (Note 2) LTC3411E ............................................. 40C to 85C LTC3411I............................................ 40C to 125C PIN CONFIGURATION TOP VIEW TOP VIEW SHDN/R 1 10 I T TH SHDN/R 1 10 I T TH SYNC/MODE 2 9 V FB SYNC/MODE 2 9 V FB SGND 3 8 PGOOD SGND 3 8 PGOOD SW 4 7 SV SW 4 7 SV IN IN PGND 5 6 PV IN PGND 5 6 PV IN MS PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE 10-LEAD (3mm 3mm) PLASTIC DFNs T = 125C, = 120C/W, = 45C/W JMAX JA JC T = 125C, = 43C/W, = 8C/W JMAX JA JC (EXPOSED PAD MUST BE SOLDERED TO SGND) ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3411EDD PBF LTC3411EDD TRPBF LADT 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3411IDD PBF LTC3411IDD TRPBF LADT 40C to 125C 10-Lead (3mm 3mm) Plastic DFN LTC3411EMS PBF LTC3411EMS TRPBF LTQT 10-Lead Plastic MSOP 40C to 85C LTC3411IMS PBF LTC3411IMS TRPBF LTQT 10-Lead Plastic MSOP 40C to 125C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3411EDD LTC3411EDD TR LADT 10-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3411IDD LTC3411IDD TR LADT 40C to 125C 10-Lead (3mm 3mm) Plastic DFN LTC3411EMS LTC3411EMS TR LTQT 10-Lead Plastic MSOP 40C to 85C LTC3411IMS LTC3411IMS TR LTQT 10-Lead Plastic MSOP 40C to 125C 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: