POWER LOSS (W) LTC3621/LTC3621-2 17V, 1A Synchronous Step-Down Regulator with 3.5A Quiescent Current Fea T Descrip T 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 LTC3621-5 1.00MHz 5V a T LTC3621-2 2.25MHz Adjustable n Portable-Handheld Scanners LTC3621-23.3 2.25MHz 3.3V n Industrial and Embedded Computing LTC3621-25 2.25MHz 5V n Automotive Applications L, LT, LTC, LTM, Burst Mode, Linear Technology, the Linear logo and LTSpice are registered n Emergency Radio trademarks and Hot Swap and LTpowerCAD are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6498466, 6611131, 6177787, 5705919, 5847554. Typical a T 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 3621fc 1 For more information www.linear.com/LTC3621 EFFICIENCY (%) ion pplica ions pplica ion uresLTC3621/LTC3621-2 a Te Maxi Mu M r a T (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 p in c F T 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 o r Der i n F Ma T 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 40C to 125C 6-Lead (2mm 3mm) Plastic DFN LTC3621IDCB-3.3 PBF LTC3621IDCB-3.3 TRPBF LGQF 40C to 125C 6-Lead (2mm 3mm) Plastic DFN 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 40C to 125C 6-Lead (2mm 3mm) Plastic DFN LTC3621IDCB-23.3 PBF LTC3621IDCB-23.3 TRPBF LGQG 40C to 125C 6-Lead (2mm 3mm) Plastic DFN 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 3621fc 2 For more information www.linear.com/LTC3621 ion or ion igura on ings bsolu