LT3479 3A, Full Featured DC/DC Converter with Soft-Start and Inrush Current Protection FEATURESDESCRIPTION n Wide Input Voltage Range: 2.5V to 24V The LT®3479 is a current mode, fi xed frequency step-up n 3A, 42V Internal Switch DC/DC converter with an internal 3A, 42V switch. Effi cien- n High Effi ciency Power Conversion: Up to 89% cies of up to 89% can be achieved in typical applications. It n Soft-Start features a programmable soft-start function to limit induc- n Frequency Set by External Resistor: 200kHz to tor current during start-up and inrush current protection 3.5MHz to protect the LT3479 during shorts and line transients. n Protection Against Input Short Circuits and Both inputs of the error amplifi er are available to the user Hot Plugging allowing positive and negative output voltages. Through n Low VCESAT Switch: 0.3V at 2.5A (Typical) an external resistor, the user can program the switch- n Capable of Positive and Negative Outputs ing frequency from 200kHz to 3.5MHz. The low profi le n Available in Thermally Enhanced 14-Lead (0.75mm) 14-pin, 4mm × 3mm DFN package provides (4mm × 3mm) DFN and 16-Lead TSSOP Packages excellent thermal performance in a small footprint. The LT3479 is also available in a thermally enhanced 16-pin APPLICATIONS TSSOP package. n High Power LED Driver 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 DSL Modems n Distributed Power TYPICAL APPLICATION5V to 12V Boost Converter5V to 12V Effi ciency 4.7μH V 90 V OUT IN 12V 5V 0.8A 2.2μF 85 200k 10μF V V L SW IN S FBN 80 SHDN 23.2k LT3479 V 75 REF SS EFFICIENCY (%) 70 10nF FBP R GND V T C 65 10k 17.8k 2.2nF 60 0 0.2 0.4 0.6 0.8 3479 TA01 IOUT (A) 3479 TA02 3479fc 1
