LTC3407-2 Dual Synchronous, 800mA, 2.25MHz Step-Down DC/DC Regulator FEATURES DESCRIPTION n High Ef ciency: Up to 95% The LTC 3407-2 is a dual, constant-frequency, synchro- n Very Low Quiescent Current: Only 40A nous step down DC/DC converter. Intended for low power n 2.25MHz Constant-Frequency Operation applications, it operates from 2.5V to 5.5V input voltage n High Switch Current: 1.2A on Each Channel range and has a constant 2.25MHz switching frequency, n No Schottky Diodes Required allowing the use of tiny, low cost capacitors and inductors n Low R Internal Switches: 0.35 with a pro le 1.2mm. Each output voltage is adjustable DS(ON) n Current Mode Operation for Excellent Line from 0.6V to 5V. Internal synchronous 0.35, 1.2A power and Load Transient Response switches provide high ef ciency without the need for n Short-Circuit Protected external Schottky diodes. n Low Dropout Operation: 100% Duty Cycle A user selectable mode input is provided to allow the user n Ultralow Shutdown Current: I < 1A Q to trade-off noise ripple for low power ef ciency. Burst n Output Voltages from 5V down to 0.6V Mode operation provides high ef ciency at light loads, n Power-On Reset Output while pulse-skipping mode provides low noise ripple at n Externally Synchronizable Oscillator light loads. n Small Thermally Enhanced MSOP and 3mm 3mm To further maximize battery life, the P-channel MOSFETs DFN Packages are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only APPLICATIONS 40A. In shutdown, the device draws <1A. n PDAs/Palmtop PCs L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n Digital Cameras of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Cellular Phones n Portable Media Players n PC Cards n Wireless and DSL Modems TYPICAL APPLICATION V = 2.5V* IN TO 5.5V LTC3407-2 Ef ciency Curve C1 R5 10F 100k RUN2 V RUN1 IN 100 MODE/SYNC POR RESET 95 2.5V LTC3407-2 L2 L1 90 2.2H 2.2H 1.8V V = 2.5V V = 1.8V OUT2 OUT1 SW2 SW1 AT 800mA AT 800mA 85 C5, 22pF C4, 22pF 80 V V FB1 75 FB2 R4 R2 GND C3 C2 R3 R1 887k 604k 70 10F 10F 280k 301k V = 3.3V IN 65 Burst Mode OPERATION NO LOAD ON OTHER CHANNEL 60 C1, C2, C3: TAIYO YUDEN JMK316BJ106ML L1, L2: MURATA LQH32CN2R2M33 3407 TA01 1 10 100 1000 *V CONNECTED TO V FOR V b 2.8V OUT IN IN LOAD CURRENT (mA) 3407 TA02 Figure 1. 2.5V/1.8V at 800mA Step-Down Regulators 34072fc 1 EFFICIENCY (%)LTC3407-2 ABSOLUTE MAXIMUM RATINGS (Note 1) V Voltages .................................................0.3V to 6V Ambient Operating Temperature Range (Note 2) IN V , V Voltages .......................... 0.3V to V + 0.3V LTC3407E-2 ......................................... 40C to 85C FB1 FB2 IN RUN1, RUN2 Voltages .................................0.3V to V LTC3407I-2 ........................................ 40C to 125C IN Junction Temperature (Note 5) ............................. 125C MODE/SYNC Voltage ........................ 0.3V to V + 0.3V IN Storage Temperature Range ................... 65C to 150C SW1, SW2 Voltage ........................... 0.3V to V + 0.3V IN Lead Temperature (Soldering, 10 sec) POR Voltage ................................................. 0.3V to 6V MSE Package Only ............................................ 300C Re ow Peak Body Temperature ............................ 260C PIN CONFIGURATION TOP VIEW TOP VIEW V 1 10 V FB1 FB2 V 1 10 V FB1 FB2 RUN1 2 9 RUN2 RUN1 2 9 RUN2 V IN 11 V 3 11 8 POR 3 8 POR IN SW1 4 7 SW2 SW1 4 7 SW2 MODE/ GND 5 6 GND SYNC 5 6 MODE/ SYNC MSE PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE T = 125C, = 45C/W, = 10C/W 10-LEAD (3mm s 3mm) PLASTIC DFN JMAX JA JC EXPOSED PAD (PIN 11) IS PGND, MUST BE CONNECTED TO GND T = 125C, = 45C/W, = 10C/W JMAX JA JC EXPOSED PAD (PIN 11) IS PGND, MUST BE CONNECTED TO GND ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3407EDD-2 PBF LTC3407EDD-2 TRPBF LBFB 40C to 85C 10-Lead (3mm 3mm) Plastic DFN LTC3407IDD-2 PBF LTC3407IDD-2 TRPBF LBFB 40C to 125C 10-Lead (3mm 3mm) Plastic DFN LTC3407EMSE-2 PBF LTC3407EMSE-2 TRPBF LTBDZ 10-Lead Plastic MSOP 40C to 85C LTC3407IMSE-2 PBF LTC3407IMSE-2 TRPBF LTBDZ 10-Lead Plastic MSOP 40C to 125C LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3407EDD-2 LTC3407EDD-2 TR LBFB 10-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3407IDD-2 LTC3407IDD-2 TR LBFB 10-Lead (3mm 3mm) Plastic DFN 40C to 125C LTC3407EMSE-2 LTC3407EMSE-2 TR LTBDZ 10-Lead Plastic MSOP 40C to 85C LTC3407IMSE-2 LTC3407IMSE-2 TR LTBDZ 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: