POWER LOSS (W) LTC3615/LTC3615-1 Dual 4MHz, 3A Synchronous Step-Down DC/DC Converter Fea T Descrip T n High Efficiency: Up to 94% The LTC 3615/LTC3615-1 are dual 3A synchronous step- n Dual Outputs with 2 3A Output Current Capability down regulators using a current mode, constant-frequency n Low Output Ripple Burst Mode Operation: I = 130A architecture. The DC supply current is only 130A (Burst Q n 2.25V to 5.5V Input Voltage Range Mode operation at no-load) while maintaining the output n 1% Output Voltage Accuracy voltages, dropping to zero current in shutdown. The 2.25V n Output Voltages Down to 0.6V to 5.5V input supply range makes the parts ideally suited n Programmable Slew Rate at Switch Pins for single Li-Ion applications. 100% duty cycle capability n Low Dropout Operation: 100% Duty Cycle provides low dropout operation, which extends operating n Shutdown Current 1A time in battery-operated systems. n Adjustable Switching Frequency Up to 4MHz The operating frequency is externally programmable up to n Internal or External Compensation 4MHz, allowing the use of small surface mount inductors. n Selectable Pulse-Skipping/Forced Continuous/ 0, 90, or 180 (LTC3615) or 140/180 (LTC3615-1) of Burst Mode Operation with Adjustable Burst Clamp phase shift between the two channels can be selected to n Optional Active Voltage Positioning (AVP) with minimize input current ripple and output voltage ripple in a Internal Compensation dual 3A or single 6A output configuration. Programmable n Selectable 0/90/180 (LTC3615) or selectable slew rate limiting reduces EMI, and external synchroniza- 140/180 (LTC3615-1) Phase Shift Between Channels tion can be applied up to 4MHz. n Fixed Internal and Programmable External Soft-Start n The internal synchronous switches increase efficiency Accurate Start-Up Tracking Capability n and eliminate the need for external catch diodes, saving DDR Memory Mode I = 1.5A OUT n external components and board space. Available in 4mm 4mm QFN-24 and TSSOP-24 Packages The LTC3615/LTC3615-1 are offered in leadless 24-pin a T 4mm 4mm QFN and thermally enhanced 24-pin TSSOP n packages. Point-of-Load Supplies n Distributed Power Supplies L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective n Portable Computer Systems owners. Protected by U.S. Patents, including 5481178, 5994885, 6304066, 6498466, 6580258, 6611131. n DDR Memory Termination n Handheld Devices Efficiency and Power Loss vs Load Current Typical a T 100 10 V IN 90 100F SV PV PV IN IN1 IN2 0.47H V OUT1 80 1 RUN1 1.8V/3A SW1 70 TRACK/SS1 47F 422k PGOOD1 60 0.1 ITH1 LTC3615 FB1 50 SRLIM 210k R /SYNC T 40 0.01 MODE 0.47H V OUT2 30 SW2 2.5V/3A PHASE 47F 20 0.001 RUN2 665k V = 3.3V IN TRACK/SS2 2.25MHz V = 4V 10 IN FB2 PGOOD2 V = 2.5V V = 5V OUT IN 0 ITH2 SGND PGND 0.0001 210k 0.001 0.01 0.1 1 3615 TA01a OUTPUT CURRENT (A) 3615 TA01b 3615fb 1 For more information www.linear.com/LTC3615 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3615/LTC3615-1 a T e Maxi Mu M r a T (Notes 1, 11) PV , PV Voltages ....................0.3V to SV + 0.3V Operating Junction Temperature IN1 IN2 IN SV Voltage ................................................ 0.3V to 6V Range (Notes 2, 11) ............................... 55C to 150C IN SW1 Voltage .............................0.3V to (PV + 0.3V) Storage Temperature.............................. 65C to 150C IN1 SW2 Voltage ..............................0.3V to (PV + 0.3V) Lead Soldering Temperature (eTSSOP) .................300C IN2 PGOOD1, PGOOD2 Voltages ........................ 0.3V to 6V Reflow Peak Body Temperature (QFN) ..................260C All Other Pins .............................. 0.3V to (SV + 0.3V) IN p c F T TOP VIEW TOP VIEW 1 MODE PHASE 24 FB2 2 23 FB1 24 23 22 21 20 19 3 22 ITH1 ITH2 ITH1 1 18 PGOOD1 TRACK/SS2 4 21 TRACK/SS1 FB1 2 17 SRLIM SGND 5 20 SV IN MODE 3 16 PGOOD2 6 PV 25 PV 19 IN2 IN1 25 PGND PHASE 4 15 R /SYNC T PV 7 18 PV IN2 PGND IN1 FB2 5 14 RUN1 8 17 SW1 SW2 ITH2 6 13 RUN2 SW2 9 16 SW1 7 8 9 10 11 12 RUN2 10 15 PGOOD1 11 SRLIM RUN1 14 R /SYNC 12 13 PGOOD2 T FE PACKAGE UF PACKAGE 24-LEAD (4mm 4mm) PLASTIC QFN 24-LEAD PLASTIC eTSSOP T = 150C, = 33C/W T = 150C, = 37C/W JMAX JA JMAX JA EXPOSED PAD (PIN 25) IS PGND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 25) IS PGND, MUST BE SOLDERED TO PCB o r D i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3615EFE PBF LTC3615EFE TRPBF LTC3615FE 24-Lead Plastic TSSOP 40C to 125C LTC3615IFE PBF LTC3615IFE TRPBF LTC3615FE 24-Lead Plastic TSSOP 40C to 125C LTC3615HFE PBF LTC3615HFE TRPBF LTC3615FE 24-Lead Plastic TSSOP 40C to 150C LTC3615MPFE PBF LTC3615MPFE TRPBF LTC3615FE 24-Lead Plastic TSSOP 55C to 150C LTC3615EUF PBF LTC3615EUF TRPBF 3615 24-Lead (4mm 4mm) Plastic QFN 40C to 125C LTC3615IUF PBF LTC3615IUF TRPBF 3615 24-Lead (4mm 4mm) Plastic QFN 40C to 125C LTC3615HUF PBF LTC3615HUF TRPBF 3615 24-Lead (4mm 4mm) Plastic QFN 40C to 150C LTC3615MPUF PBF LTC3615MPUF TRPBF 3615 24-Lead (4mm 4mm) Plastic QFN 55C to 150C LTC3615EFE-1 PBF LTC3615EFE-1 TRPBF LTC3615FE-1 24-Lead Plastic TSSOP 40C to 125C LTC3615IFE-1 PBF LTC3615IFE-1 TRPBF LTC3615FE-1 24-Lead Plastic TSSOP 40C to 125C LTC3615HFE-1 PBF LTC3615HFE-1 TRPBF LTC3615FE-1 24-Lead Plastic TSSOP 40C to 150C LTC3615MPFE-1 PBF LTC3615MPFE-1 TRPBF LTC3615FE-1 24-Lead Plastic TSSOP 55C to 150C LTC3615EUF-1 PBF LTC3615EUF-1 TRPBF 36151 24-Lead (4mm 4mm) Plastic QFN 40C to 125C LTC3615IUF-1 PBF LTC3615IUF-1 TRPBF 36151 24-Lead (4mm 4mm) Plastic QFN 40C to 125C LTC3615HUF-1 PBF LTC3615HUF-1 TRPBF 36151 24-Lead (4mm 4mm) Plastic QFN 40C to 150C LTC3615MPUF-1 PBF LTC3615MPUF-1 TRPBF 36151 24-Lead (4mm 4mm) Plastic QFN 55C to 150C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: