AF1937 Datasheet | Alfa-MOS

Alfa-MOS Technology AF1937 20V White LED Step UP Converter General Description The AF1937 is a step-up DC/DC converter specifically designed to drive white LEDs with a constant current. The device can drive two, three or four LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The output capacitor can be as small as 0.22µF, saving space versus alternative solutions. A low 95mV feedback voltage minimizes power loss for better efficiency. Features Inherently Matched LED Current High Efficiency: 84% Typical Drives Up to Four LEDs from a 3.2V Supply Drives Up to Six LEDs from a 5V Supply 36V Rugged Bipolar Switch Fast 1.2MHz Switching Frequency Uses Tiny 1mm Tall Inductors Requires Only 0.22µF Output Capacitor Application Battery Power Equipment Notebook puters PDA Cellular Phone Digital Cameras MP3 Players GPS Receivers Pin Define SOT-23-5L Marking...