IL1937 Datasheet, PDF (1/6 Pages) IK Semicon Co., Ltd – Uses tiny 1mm Tall Inductors

TECHNICAL DATA
White LED Step-Up Converter
Description
The IL1937 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 battery. Series connection of the
LEDs provides identical LED currents resulting in
uniform brightness and eliminating the need for ballast
resistors. The IL1937 operates at 1. 2MHz, allowing
the use of tiny external components. The output
capacitor can be as small as 0.22uF, saving space
and cost versus alternative solutions.
A low 95mV feedback voltage minimizes power loss in
the current setting resistor for better efficiency.
The device can used in mobile phones, PDAs,
Handheld Computers, calculators, digital cameras,
MP3-players, GPS-receivers
Features
 Internally determined LED current
 High Efficiency: 84% Typical
 Drives Up to 4 LEDs from a 3.2V Supply
 Drives Up to 6 LEDs from a 5V Supply
 36V rugged bipolar switch
 Fast 1.2MHz switching frequency
 Uses tiny 1mm Tall Inductors
 Requires only 0.22uF output capacitor
Applications
 Cellular Phones
 PDAs, Handheld Computers
 Digital Cameras
 MP3 Players
 GPS Receivers
Pin Description
IL1937
1
2011, April, Ver. 01