POWER LOSS (W) LTC3621/LTC3621-2 17V, 1A Synchronous Step-Down Regulator with 3.5A Quiescent Current FEATURES DESCRIPTION n Wide V Range: 2.7V to 17V The LTC 3621/LTC3621-2 is a high efficiency 17V, 1A IN n Wide V Range: 0.6V to V synchronous monolithic step-down regulator. The switch- OUT IN n ing frequency is fixed to 1MHz or 2.25MHz with a 40% 95% Max Efficiency n synchronizing range. The regulator features ultralow quies- Low I < 3.5A, Zero-Current Shutdown Q n cent current and high efficiencies over a wide V range. Constant Frequency (1MHz/2.25MHz) OUT n Full Dropout Operation with Low I Q The step-down regulator operates from an input voltage n 1A Rated Output Current range of 2.7V to 17V and provides an adjustable output n 1% Output Voltage Accuracy range from 0.6V to V while delivering up to 1A of output IN n Current Mode Operation for Excellent Line and Load current. A user-selectable mode input is provided to allow Transient Response the user to trade off ripple noise for light load efficiency n Synchronizable to External Clock Burst Mode operation provides the highest efficiency at n Pulse-Skipping, Forced Continuous, Burst Mode light loads, while pulse-skipping mode provides the lowest Operation voltage ripple. The MODE pin can also be used to allow the n Internal Compensation and Soft-Start user to sync the switching frequency to an external clock. n Overtemperature Protection LTC3621 Options n Compact 6-Lead DFN (2mm 3mm) Package or PART NAME FREQUENCY V OUT Thermally-Enhanced MS8E Package with Power LTC3621 1.00MHz Adjustable Good Output and Independent SGND Pin LTC3621-3.3 1.00MHz 3.3V n AEC-Q100 Qualified for Automotive Applications LTC3621-5 1.00MHz 5V LTC3621-2 2.25MHz Adjustable APPLICATIONS LTC3621-23.3 2.25MHz 3.3V n Portable-Handheld Scanners LTC3621-25 2.25MHz 5V n Industrial and Embedded Computing All registered trademarks and trademarks are the property of their respective owners. Protected n Automotive Applications by U.S. patents, including 5481178, 6580258, 6498466, 6611131, 6177787, 5705919, 5847554. n Emergency Radio TYPICAL APPLICATION Efficiency and Power Loss vs Load at 1MHz 100 0.6 2.5V V with 400mA Burst Clamp, f = 1MHz OUT SW V = 12V IN 90 4.7H 0.5 V EFFICIENCY OUT V 80 IN V SW 2.5V IN 2.7V TO 17V 1A 70 10F 604k 22pF LTC3621 0.4 60 RUN 22F FB MODE/SYNC 191k 3621 TA01a 50 0.3 INTV POWER LOSS CC 40 GND 1F 0.2 30 20 V = 5V OUT 0.1 V = 3.3V OUT 10 V = 2.5V OUT 0 0 0 0.2 0.4 0.6 0.8 1 LOAD CURRENT (A) 3621 TA01b Rev. D 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3621/LTC3621-2 ABSOLUTE MAXIMUM RATINGS (Note 1) V Voltage ................................................. 17V to 0.3V Operating Junction Temperature Range (Notes 3, 6, 7) IN RUN Voltage................................................ V to 0.3V LTC3621E, LTC3621I .......................... 40C to 125C IN MODE/SYNC, FB Voltages ............................ 6V to 0.3V LTC3621H .......................................... 40C to 150C PGOOD Voltages .......................................... 6V to 0.3V Storage Temperature Range .................. 65C to 150C PIN CONFIGURATION TOP VIEW TOP VIEW 1 6 MODE/SYNC SW SW 1 8 SGND 7 V 2 9 7 MODE/SYNC IN 5 INTV V 2 IN CC GND GND RUN 3 6 INTV CC PGOOD 4 5 FB FB RUN 3 4 MS8E PACKAGE 8-LEAD PLASTIC MSOP DCB PACKAGE T = 150C, = 40C/W, = 10C/W JMAX JA JC 6-LEAD (2mm 3mm) PLASTIC DFN EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 64C/W, = 9.6C/W JMAX JA JC EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3621EDCB PBF LTC3621EDCB TRPBF LGDG 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621IDCB PBF LTC3621IDCB TRPBF LGDG 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621EDCB-3.3 PBF LTC3621EDCB-3.3 TRPBF LGQF 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621IDCB-3.3 PBF LTC3621IDCB-3.3 TRPBF LGQF 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621EDCB-5 PBF LTC3621EDCB-5 TRPBF LGQC 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621IDCB-5 PBF LTC3621IDCB-5 TRPBF LGQC 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621EMS8E PBF LTC3621EMS8E TRPBF LTGDH 8-Lead Plastic MSOP 40C to 125C LTC3621IMS8E PBF LTC3621IMS8E TRPBF LTGDH 8-Lead Plastic MSOP 40C to 125C LTC3621HMS8E PBF LTC3621HMS8E TRPBF LTGDH 8-Lead Plastic MSOP 40C to 150C LTC3621EMS8E-3.3 PBF LTC3621EMS8E-3.3 TRPBF LTGNY 8-Lead Plastic MSOP 40C to 125C LTC3621IMS8E-3.3 PBF LTC3621IMS8E-3.3 TRPBF LTGNY 8-Lead Plastic MSOP 40C to 125C LTC3621HMS8E-3.3 PBF LTC3621HMS8E-3.3 TRPBF LTGNY 8-Lead Plastic MSOP 40C to 150C LTC3621EMS8E-5 PBF LTC3621EMS8E-5 TRPBF LTGNX 8-Lead Plastic MSOP 40C to 125C LTC3621IMS8E-5 PBF LTC3621IMS8E-5 TRPBF LTGNX 8-Lead Plastic MSOP 40C to 125C LTC3621HMS8E-5 PBF LTC3621HMS8E-5 TRPBF LTGNX 8-Lead Plastic MSOP 40C to 150C LTC3621EDCB-2 PBF LTC3621EDCB-2 TRPBF LGHY 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621IDCB-2 PBF LTC3621IDCB-2 TRPBF LGHY 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621EDCB-23.3 PBF LTC3621EDCB-23.3 TRPBF LGQG 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621IDCB-23.3 PBF LTC3621IDCB-23.3 TRPBF LGQG 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621EDCB-25 PBF LTC3621EDCB-25 TRPBF LGQD 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LTC3621IDCB-25 PBF LTC3621IDCB-25 TRPBF LGQD 6-Lead (2mm 3mm) Plastic DFN 40C to 125C Rev. D 2 For more information www.analog.com