LT3663 1.2A Step-Down Switching Regulator with Output Current Limit FeaTuresDescripTion 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 fSW = 1.5MHz LT3663-X f The LT3663 includes a low current shutdown mode, input SW = 1MHZ n Low Switch V overvoltage and undervoltage lockout, and thermal shut- CESAT: 275mV at 1A n Internally Compensated down. Internal compensation and boost diode minimize the n Thermal Protection number of external exponents. 3.3V and 5V fixed output n Thermally Enhanced 8-Pin 2mm × 3mm DFN and voltage versions are available. MSOP Packages The LT3663 is available in 8-lead DFN and MSOP packages with exposed pads for low thermal resistance. applicaTions 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 applicaTion5V Step-Down ConverterEfficiency 100 VIN VIN BOOST 2.2µF 90 LT3663 0.1µF VIN = 8V SW 80 VIN = 15V V ON OFF RUN 6.8µH IN = 30V 70 ISENSE EFFICIENCY (%) 60 ILIM VOUT VOUT 28.7k 59k 22µF 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 For more information For more information www.linear.com/LT3663 1 Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Operation Applications Information Package Description