POWER LOSS (W) LTC3417A-1 Dual Synchronous 1.5A/1A 4MHz Step-Down DC/DC Regulator with POR FEATURES DESCRIPTION n High Ef ciency: Up to 95% The LTC 3417A-1 is a dual constant frequency, synchro- n 1.5A/1A Guaranteed Minimum Output Current nous step-down DC/DC converter. Intended for medium n Synchronizable to External Clock power applications, it operates from a 2.25V to 5.5V input n Power-On-Reset Output voltage range and has a constant programmable switching n No Schottky Diodes Required frequency, allowing the use of tiny, low cost capacitors n Programmable Frequency Operation: 1.5MHz or and inductors 2mm or less in height. Each output voltage Adjustable From 0.6MHz to 4MHz is adjustable from 0.8V to 5V. Internal synchronous, low n Low Ripple (< 35mV ) BurstMode Operation R power switches provide high ef ciency without DS(ON) P-P n Low R Internal Switches the need for external Schottky diodes. DS(ON) n Short-Circuit Protected The open drain POR pin goes low when either output n V : 2.25V to 5.5V IN voltage falls 6% below regulation. The output will remain n Current Mode Operation for Excellent Line and Load low 150ms longer than the duration of the out of regula- Transient Response tion condition. n 125A Quiescent Current in Sleep Mode n A user selectable mode input allows the user to trade Ultralow Shutdown Current: I < 1A Q n off ripple voltage for light load ef ciency. Burst Mode Low Dropout Operation: 100% Duty Cycle n operation provides high ef ciency at light loads, while Phase Pin Selects 2nd Channel Phase Relationship pulse skip mode provides low ripple noise at light loads. with Respect to 1st Channel n A phase mode pin allows the second channel to operate Internal Soft-Start with Individual Run Pin Control n in-phase or 180 out-of-phase with respect to channel 1. Available in Small Thermally Enhanced Out-of-phase operation produces lower RMS current on (3mm 5mm) DFN and 20-Lead TSSOP Packages V and thus lower stress on the input capacitor. IN APPLICATIONS To further maximize battery life, the P-channel MOSFETs n GPS/Navigation Systems are turned on continuously in dropout (100% duty cycle) n Automotive Instrumentation and both channels draw a total quiescent current of only n PC Cards 100A. In shutdown, the device draws <1A. n Industrial Power Supplies L, LT, LTC and LTM and Burst Mode are registered trademarks of Linear Technology n Corporation. All other trademarks are the property of their respective owners. Protected by U.S. General Purpose Point of Load DC/DC Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6144194. OUT2 Ef ciency TYPICAL APPLICATION (Burst Mode Operation) V 100 10 IN REFER TO FIGURE 4 2.5V TO 5.5V 10 F 100k V IN 95 1 POR RESET FREQ EFFICIENCY 1.5H 2.2H V V OUT1 OUT2 90 1.8V SW2 2.5V SW1 22pF 22pF 0.1 1.5A 1A RUN2 V RUN1 V IN IN 85 LTC3417A-1 511k 866k 0.01 V V FB2 POWER LOSS FB1 80 47 F 412k 412k 22F 0.001 75 I V = 3.6V I TH2 IN TH1 V = 2.5V OUT 5.9k 2.87k GND FREQ = 1MHz 0.0001 70 0.001 0.01 0.1 1 2200pF 6800pF LOAD CURRENT (A) 3417A-1 TA01 3417A-1 TA01a 3417a1fa 1 EFFICIENCY (%)LTC3417A-1 ABSOLUTE MAXIMUM RATINGS (Note 1) V , V Voltages ...................................... 0.3V to 6V POR Voltage ................................................ 0.3V to 6V IN1 IN2 SYNC/MODE, SW1, SW2, RUN1, Operating Temperature Range (Note 2) RUN2, V , V , PHASE, FREQ, LTC3417AE-1 ...................................... 40C to 85C FB1 FB2 I , I Voltages........ 0.3V to ((V or V ) + 0.3V) LTC3417AI-1 ..................................... 40C to 125C TH1 TH2 IN1 IN2 V V , V V .......................................... 0.3V Junction Temperature (Notes 7, 8) ...................... 125C IN1 IN2 IN2 IN1 Storage Temperature Range ................... 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 POR I 6 11 POR TH2 TH2 RUN2 8 13 SW2 RUN2 7 10 SW2 V 8 9 SYNC/MODE V 9 12 SYNC/MODE IN2 IN2 PGND2 10 11 PGND2 DHC PACKAGE 16-LEAD (5mm 3mm) PLASTIC DFN FE PACKAGE 20-LEAD PLASTIC TSSOP T = 125C, = 43C/ W JMAX JA EXPOSED PAD (PIN 17) IS PGND2/GNDD T = 125C, = 38C/ W JMAX JA MUST BE SOLDERED TO PCB 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 LTC3417AEDHC-1 PBF LTC3417AEDHC-1 TRPBF 3417A1 16-Lead (3mm 5mm) Plastic DFN 40C to 85C LTC3417AIDHC-1 PBF LTC3417AIDHC-1 TRPBF 3417A1 16-Lead (3mm 5mm) Plastic DFN 40C to 125C LTC3417AEFE-1 PBF LTC3417AEFE-1 TRPBF LTC3417AFE-1 20-Lead Plastic TSSOP 40C to 85C LTC3417AIFE-1 PBF LTC3417AIFE-1 TRPBF LTC3417AFE-1 20-Lead Plastic TSSOP 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: