POWER LOSS (W) LTC3419 Dual Monolithic 600mA Synchronous Step-Down Regulator FEATURES DESCRIPTION n High Ef ciency Dual Step-Down Outputs: Up to 96% The LTC 3419 is a dual, 2.25MHz, constant-frequency, n 600mA Current per Channel at V = 3V synchronous step-down DC/DC converter in a tiny IN n Only 35A Quiescent Current During Operation 3mm 3mm DFN package. 100% duty cycle provides (Both Channels) low dropout operation, extending battery life in portable n 2.25MHz Constant-Frequency Operation systems. Low output voltages are supported with the 0.6V n 2.5V to 5.5V Input Voltage Range feedback reference voltage. Each regulator can supply n Low Dropout Operation: 100% Duty Cycle 600mA output current. n No Schottky Diodes Required The input voltage range is 2.5V to 5.5V, making it ideal n Internally Compensated for All Ceramic Capacitors for Li-Ion and USB powered applications. Supply current n Independent Internal Soft-Start for Each Channel during operation is only 35A and drops to <1A in n Available in Fixed Output Versions shutdown. A user-selectable mode input allows the user n Current Mode Operation for Excellent Line and Load to trade off between high ef ciency Burst Mode operation Transient Response and pulse-skipping mode. n 0.6V Reference Allows Low Output Voltages n An internally set 2.25MHz switching frequency allows the User-Selectable Burst Mode Operation n use of tiny surface mount inductors and capacitors. Internal Short-Circuit Protected n soft-start reduces inrush current during start-up. Both Ultralow Shutdown Current: I < 1A Q n outputs are internally compensated to work with ceramic Available in Small MSOP or 3mm 3mm DFN-8 output capacitors. The LTC3419 is available in a low pro le Packages (0.75mm) 3mm 3mm DFN package. The LTC3419 is also available in a xed output voltage con guration selected APPLICATIONS via internal resistor dividers (see Table 2). n Cellular Telephones , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other n Digital Still Cameras trademarks are the property of their respective owners. Protected by U.S. Patents, n Wireless and DSL Modems including 5481178, 6127815, 6304066, 6498466, 6580258, 6611131. n Portable Media Players n PDAs/Palmtop PCs TYPICAL APPLICATION Ef ciency and Power Loss vs Output Current Dual Monolithic Buck Regulator in 8-Lead 3 3 DFN 100 10 V = 3.6V IN 90 V IN 2.5V TO 5.5V 80 1 10F 70 RUN2 V RUN1 IN MODE 60 0.1 LTC3419 50 3.3H3.3H V V OUT2 OUT1 2.5V AT 1.8V AT SW2 SW1 40 0.01 600mA 600mA 22pF 22pF 30 20 0.001 V = 1.2V V V OUT FB2 FB1 10 V = 1.8V 118k GND 187k OUT 10F 10F 59k 59k V = 2.5V OUT 0 0.0001 0.1 1 10 100 1000 3419 TA01 OUTPUT CURRENT (mA) 3419 TA01b 3419fa 1 EFFICIENCY (%)LTC3419 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage (V ) ............................. 0.3 to 6V Peak SW Source and Sink Current (Note 2) .............1.3A IN V , V ........................................0.3V to V + 0.3V Operating Junction Temperature Range FB1 FB2 IN RUN1, RUN2, MODE ........................0.3V to V + 0.3V (Note 3) .................................................40 to 125C IN SW1, SW2 .......................................0.3V to V + 0.3V Junction Temperature (Note 6) ............................. 125C IN P-Channel SW Source Current (DC) (Note 2) .......800mA Storage Temperature Range ...................65C to 125C N-Channel SW Source Current (DC) (Note 2) ......800mA Lead Temperature (Soldering, 10 sec) MSOP Package ................................................. 300C PIN CONFIGURATION TOP VIEW TOP VIEW V 1 8 V FB1 FB2 V 1 10 V FB1 FB2 RUN1 2 7 RUN2 RUN1 2 9 RUN2 9 MODE 3 8 SW2 MODE SW2 3 6 SW1 4 7 V IN SW1 4 5 V IN GND 5 6 GND MS PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE T = 125C, = 120C/W 8-LEAD (3mm s 3mm ) PLASTIC DFN JMAX JA T = 125C, = 40C/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 LTC3419EDD PBF LTC3419EDD TRPBF LCQJ 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3419EDD-1 PBF LTC3419EDD-1 TRPBF LCWW 8-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3419IDD PBF LTC3419IDD TRPBF LCQJ 40C to 125C 8-Lead (3mm 3mm) Plastic DFN LTC3419IDD-1 PBF LTC3419IDD-1 TRPBF LCWW 40C to 125C 8-Lead (3mm 3mm) Plastic DFN LTC3419EMS PBF LTC3419EMS TRPBF LTCQK 10-Lead Plastic MSOP 40C to 125C LTC3419EMS-1 PBF LTC3419EMS-1 TRPBF LTCWX 10-Lead Plastic MSOP 40C to 125C LTC3419IMS PBF LTC3419IMS TRPBF LTCQK 10-Lead Plastic MSOP 40C to 125C LTC3419IMS-1 PBF LTC3419IMS-1 TRPBF LTCWX 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. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: