LT3663 1.2A Step-Down Switching Regulator with Output Current Limit FeaT DescripT n Wide Input Range: The LT 3663 is a current mode step-down switching regu- Operation from 7.5V to 36V lator with programmable output current limit. The current Overvoltage Lockout Protects Circuit through 60V limit accurately controls the system power dissipation and Transients reduces the size of the power path components. n Programmable Output Current Limit (0.4A to 1.2A) The wide operating input voltage range of 7.5V to 36V (60V n 3.3V and 5V Fixed Output Voltage Options transient) suits the LT3663 to a variety of input sources, n Integrated Boost Diode including unregulated 12V wall adapters, 24V industrial n Fixed Frequency, Peak Current Mode Control supplies, and automotive power. LT3663 f = 1.5MHz SW The LT3663 includes a low current shutdown mode, input LT3663-X f = 1MHZ SW n overvoltage and undervoltage lockout, and thermal shut- Low Switch V : 275mV at 1A CESAT n down. Internal compensation and boost diode minimize the Internally Compensated n number of external exponents. 3.3V and 5V fixed output Thermal Protection n voltage versions are available. Thermally Enhanced 8-Pin 2mm 3mm DFN and MSOP Packages The LT3663 is available in 8-lead DFN and MSOP packages with exposed pads for low thermal resistance. Ta L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Distributed Supply Regulation n Automotive Battery Regulation n Industrial Supplies n Wall Transformer Regulation Typical Ta 5V Step-Down Converter Efficiency 100 V V BOOST IN IN 2.2F 90 0.1F LT3663 V = 8V IN SW V = 15V 80 IN V = 30V IN RUN 6.8H ON OFF 70 I SENSE 60 I V V LIM OUT OUT 28.7k 59k 22F 50 FB GND 40 11k 0.1 0.3 0.5 0.7 0.9 1.1 1.3 3663 TA01 OUTPUT CURRENT (A) 3663 TA01b 3663fc 1 For more information For more information www.linear.com/LT3663 EFFICIENCY (%) ion pplica ions pplica ion uresLT3663 Ta e MaxiMMu Tar (Note 1) Operating Junction Temperature Range (Note 3) Input Voltage (V ) (Note 2) ......................................60V IN LT3663E ............................................. 40C to 125C BOOST Pin Voltage ...................................................50V LT3663I .............................................. 40C to 125C BOOST Pin Above SW Pin .........................................25V LT3663H ............................................ 40C to 150C V , V , I , FB Pins .......................................6V OUTS OUT SENSE Storage Temperature .............................. 65C to 150C RUN Pin (Note 2) ......................................................60V in p Fc T LT3663 LT3663-X TOP VIEW TOP VIEW 8 V 1 8 SW V 1 SW IN IN 7 RUN 2 7 BOOST RUN 2 BOOST 9 9 GND GND FB 6 I V 3 6 I 3 OUTS SENSE SENSE I 5 V I 4 5 V 4 LIM OUT LIM OUT DCB PACKAGE DCB PACKAGE 8-LEAD (2mm 3mm) PLASTIC DFN 8-LEAD (2mm 3mm) PLASTIC DFN = 64C/W = 64C/W JA JA EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB LT3663 LT3663-X TOP VIEW TOP VIEW V 1 8 SW IN V 1 8 SW IN RUN 2 7 BOOST 9 7 BOOST RUN 2 9 FB 3 GND 6 I SENSE V 3 GND 6 I SENSE OUTS I 4 5 V 5 V LIM OUT I 4 LIM OUT MSE PACKAGE MSE PACKAGE 8-LEAD PLASTIC MSOP 8-LEAD PLASTIC MSOP = 35C/W = 35C/W JA JA EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB Der inFMTa LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3663EDCB PBF LT3663EDCB TRPBF LDVK 8-Lead (2mm 3mm) Plastic DFN 40C to 125C LT3663IDCB PBF LT3663IDCB TRPBF LDVK 8-Lead (2mm 3mm) Plastic DFN 40C to 125C LT3663EDCB-3.3 PBF LT3663EDCB-3.3 TRPBF LFMW 8-Lead (2mm 3mm) Plastic DFN 40C to 125C LT3663IDCB-3.3 PBF LT3663IDCB-3.3 TRPBF LFMW 40C to 125C 8-Lead (2mm 3mm) Plastic DFN LT3663EDCB-5 PBF LT3663EDCB-5 TRPBF LFMY 8-Lead (2mm 3mm) Plastic DFN 40C to 125C LT3663IDCB-5 PBF LT3663IDCB-5 TRPBF LFMY 8-Lead (2mm 3mm) Plastic DFN 40C to 125C LT3663EMS8E PBF LT3663EMS8E TRPBF LTDWT 8-Lead Plastic MSOP 40C to 125C LT3663IMS8E PBF LT3663IMS8E TRPBF LTDWT 8-Lead Plastic MSOP 40C to 125C LT3663HMS8E PBF LT3663HMS8E TRPBF LTDWT 8-Lead Plastic MSOP 40C to 150C LT3663EMS8E-3.3 PBF LT3663EMS8E-3.3 TRPBF LTFMX 8-Lead Plastic MSOP 40C to 125C LT3663IMS8E-3.3 PBF LT3663IMS8E-3.3 TRPBF LTFMX 8-Lead Plastic MSOP 40C to 125C LT3663HMS8E-3.3 PBF LT3663HMS8E-3.3 TRPBF LTFMX 8-Lead Plastic MSOP 40C to 150C LT3663EMS8E-5 PBF LT3663EMS8E-5 TRPBF LTFMZ 8-Lead Plastic MSOP 40C to 125C 3663fc 2 For more information www.linear.com/LT3663 ion or or ion igura on ings bsolu