OM5448

Data Sheet INTEGRATED CIRCUIT 2004 Oct 15 OM5448 m o .c U 4 t e e h S a t a .D w Low w Voltage LED Driver and Boost Converter w Integrated Electronic Solutions 1 Butler Drive Hendon SA 5014 Australia m o .c U 4 t e e h S a at .D w w w Integrated Electronic Solutions, Hendon, South Australia Data Sheet Low Voltage LED Driver and Boost Converter CONTENTS 1 2 3 4 5 5.1 5.2 6 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 8 9 10 10.1 10.2 10.3 10.3.1 10.3.2 FEATURES GENERAL DESCRIPTION QUICK REFERENCE DATA ORDERING INFORMATION PINNING INFORMATION Pinning layout Pin description BLOCK DIAGRAM FUNCTIONAL DESCRIPTION OM5448 function Voltage reference Enable input (EN pin) Set output current threshold (SETI pin) Saturation voltage threshold detector Monostable time delay Output drive transistor Choke selection: Efficiency LIMITING VALUES CHARACTERISTICS APPLICATION INFORMATION Circuit design considerations Simple pulse driven LED circuit DC LED drive Performance graphs for DC led drive, efficiency SETI graphs against LED current 10.4 10.5 10.6 10.7 10.8 10.9 10.10 10.11 10.12 10.13 10.14 10.15 11 12 12.1 12.2 12.2.1 12.2.2 12.3 12.3.1 12.3.2 12.3.3 13 14 15 OM5448 Switched LED brightness Series and parallel LED connection Supply voltage sensitivity Compensation of output drive current against supply voltage variation LED drive temperature sensitivity Voltage boost power supply Regulated boost power supply Voltage multiplier power supply Regulated voltage multiplier power supply Negative reg...