LTC3407 Dual Synchronous, 600mA, 1.5MHz Step-Down DC/DC Regulator FEATURES DESCRIPTION n High Ef ciency: Up to 96% The LTC 3407 is a dual, constant frequency, synchronous n Very Low Quiescent Current: Only 40A step down DC/DC converter. Intended for low power ap- n 1.5MHz Constant Frequency Operation plications, it operates from 2.5V to 5.5V input voltage n High Switch Current: 1A on Each Channel range and has a constant 1.5MHz switching frequency, n No Schottky Diodes Required allowing the use of tiny, low cost capacitors and inductors n Low R Internal Switches: 0.35 2mm or less in height. Each output voltage is adjustable DS(ON) n Current Mode Operation for Excellent Line from 0.6V to 5V. Internal synchronous 0.35, 1A 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 ripple noise 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 ripple noise 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 LTC3407 Ef ciency Curve V = 2.5V IN TO 5.5V 100 R5 C1 100k 10F RUN2 V RUN1 IN 95 2.5V MODE/SYNC POR RESET 90 1.8V LTC3407 L2 L1 85 2.2H 2.2H V = 2.5V V = 1.8V OUT2 OUT1 SW2 SW1 80 AT 600mA AT 600mA C5, 22pF C4, 22pF 75 V 70 V FB1 FB2 R4 R2 V = 3.3V GND IN C3 C2 R3 R1 887k 887k 65 Burst Mode OPERATION 10F 10F 280k 442k NO LOAD ON OTHER CHANNEL 60 1 10 100 1000 LOAD CURRENT (mA) C1, C2, C3: TAIYO YUDEN JMK316BJ106ML L1, L2: MURATA LQH32CN2R2M33 3407 TA01 3407 TA02 Figure 1. 2.5V/1.8V at 600mA Step-Down Regulators 3407fa 1 EFFICIENCY (%)LTC3407 ABSOLUTE MAXIMUM RATINGS (Note 1) V Voltages .................................................0.3V to 6V Junction Temperature (Note 5) ............................. 125C IN V , V Voltages .......................... 0.3V to V + 0.3V Storage Temperature Range FB1 FB2 IN RUN1, RUN2 Voltages .................................0.3V to V LTC3407EMSE ................................... 65C to 150C IN MODE/SYNC Voltage ........................ 0.3V to V + 0.3V LTC3407EDD ...................................... 65C to 125C IN SW1, SW2 Voltage ........................... 0.3V to V + 0.3V Lead Temperature (Soldering, 10 sec) IN POR Voltage ................................................. 0.3V to 6V LTC3407EMSE only ........................................... 300C Ambient Operating Temperature Range (Note 2) .................................... 40C to 85C PIN CONFIGURATION TOP VIEW TOP VIEW V 1 10 V FB1 FB2 V 1 10 V FB1 FB2 RUN1 9 RUN2 2 RUN1 2 9 RUN2 V IN 3 11 POR 8 V 3 11 8 POR IN SW1 SW1 4 7 SW2 4 7 SW2 MODE/ GND 5 6 GND 5 6 MODE/ SYNC SYNC MSE PACKAGE 10-LEAD PLASTIC MSOP DD PACKAGE 10-LEAD (3mm 3mm) PLASTIC DFN T = 125C, = 45C/W, = 10C/W JMAX JA JC EXPOSED PAD IS PGND (PIN 11) MUST BE CONNECTED TO GND T = 125C, = 45C/W, = 10C/W JMAX JA JC EXPOSED PAD IS PGND (PIN 11) MUST BE CONNECTED TO GND ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3407EDD PBF LTC3407EDD TRPBF LAGK 10-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3407EMSE PBF LTC3407EMSE TRPBF LTABA 10-Lead (3mm 3mm) Plastic MSOP 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: