POWER LOSS (W) LTC3417 Dual Synchronous 1.4A/800mA 4MHz Step-Down DC/DC Regulator FEATURES DESCRIPTION n High Ef ciency: Up to 95% The LTC 3417 is a dual constant frequency, synchronous n 1.4A/800mA Guaranteed Minimum Output Current step-down DC/DC converter. Intended for medium power n No Schottky Diodes Required applications, it operates from a 2.25V to 5.5V input volt- n Programmable Frequency Operation: 1.5MHz or age range and has a constant programmable switching Adjustable From 0.6MHz to 4MHz frequency, allowing the use of tiny, low cost capacitors n Low R Internal Switches and inductors 2mm or less in height. Each output voltage DS(ON) n Short-Circuit Protected is adjustable from 0.8V to 5V. Internal synchronous low n V : 2.25V to 5.5V R power switches provide high ef ciency without IN DS(ON) n Current Mode Operation for Excellent Line and the need for external Schottky diodes. Load Transient Response A user selectable mode input allows the user to trade n 125A Quiescent Current in Sleep Mode off ripple voltage for light load ef ciency. Burst Mode n Ultralow Shutdown Current: I < 1A Q operation provides high ef ciency at light loads, while n Low Dropout Operation: 100% Duty Cycle Pulse Skip mode provides low ripple noise at light loads. n Power Good Output A phase mode pin allows the second channel to operate n Phase Pin Selects 2nd Channel Phase Relationship in-phase or 180 out-of-phase with respect to channel 1. with Respect to 1st Channel Out-of-phase operation produces lower RMS current on n Internal Soft-Start with Individual Run Pin Control V and thus lower RMS derating on the input capacitor. IN n Available in Small Thermally Enhanced To further maximize battery life, the P-channel MOSFETs (5mm 3mm) DFN and 20-Lead TSSOP Packages are turned on continuously in dropout (100% duty cycle) APPLICATIONS and both channels draw a total quiescent current of only 125A. In shutdown, the device draws <1A. n PDAs/Palmtop PCs L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. n Digital Cameras All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6144194. n Cellular Phones n PC Cards n Wireless and DSL Modems OUT2 Ef ciency TYPICAL APPLICATION (Burst Mode Operation) V IN 100 10 REFER TO FIGURE 4 2.5V TO 5.5V 10F V IN 95 1 FREQ 1.5H 2.2H EFFICIENCY V V OUT1 OUT2 90 1.8V SW2 2.5V SW1 22pF 22pF 0.1 1.4A 800mA RUN2 V RUN1 V IN IN 85 LTC3417 511k 866k 0.01 V V FB2 FB1 80 POWER LOSS 22F 412k 10F 412k 0.001 I 75 I V = 3.6V TH2 TH1 IN V = 2.5V OUT 5.9k 2.87k GND FREQ = 1MHz 0.0001 70 2200pF 6800pF 0.001 0.01 0.1 1 LOAD CURRENT (A) 3417 TA01 3417 TA01a 3417fd 1 EFFICIENCY (%)LTC3417 ABSOLUTE MAXIMUM RATINGS (Note 1) V , V Voltages ...................................... 0.3V to 6V Operating Ambient Temperature Range IN1 IN2 MODE, SW1, SW2, RUN1, (Note 2) .................................................. 40C to 85C RUN2, V , V , PHASE, FREQ, Junction Temperature (Notes 7, 8) ...................... 125C FB1 FB2 I , I Voltages............... 0.3V to (V /V + 0.3V) Storage Temperature Range TH1 TH2 IN1 IN2 V V , V V .......................................... 0.3V DFN Package ..................................... 65C to 125C IN1 IN2 IN2 IN1 PGOOD Voltage ........................................... 0.3V to 6V TSSOP Package ................................ 65C to 150C PIN CONFIGURATION TOP VIEW TOP VIEW GNDD 1 20 GNDD RUN1 2 19 PGND1 RUN1 1 16 PGND1 V 3 18 SW1 V 2 15 SW1 IN1 IN1 I 4 17 PHASE I 3 14 PHASE TH1 TH1 V 5 16 GNDA V 4 13 GNDA FB1 FB1 21 17 V 6 15 FREQ V 5 12 FREQ FB2 FB2 I 7 14 PGOOD I 6 11 PGOOD TH2 TH2 RUN2 8 13 SW2 RUN2 7 10 SW2 V 9 12 MODE V 8 9 MODE IN2 IN2 PGND2 10 11 PGND2 DHC PACKAGE 16-LEAD (3mm 5mm) PLASTIC DFN FE PACKAGE 20-LEAD PLASTIC TSSOP T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 17) IS PGND2/GNDD, MUST BE SOLDERED TO PCB T = 150C, = 38C/W JMAX JA EXPOSED PAD (PIN 21) IS PGND2/GNDD, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3417EDHC PBF LTC3417EDHC TRPBF 3417 16-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3417EFE PBF LTC3417EFE TRPBF LTC3417EFE 20-Lead Plastic TSSOP 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3417EDHC LTC3417EDHC TR 3417 16-Lead (3mm 3mm) Plastic DFN 40C to 85C LTC3417EFE LTC3417EFE TR LTC3417EFE 20-Lead Plastic TSSOP 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. For more information on lead free part marking, go to: