LT3591 Datasheet | Linear Technology

.. Features - - - - - - - - - - - LT3591 White LED Driver with Integrated Schottky in 3mm × 2mm DFN DESCRIPTION The LT®3591 is a fixed frequency step-up DC/DC converter specifically designed to drive up to ten white 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 device Features a unique high side LED current sense that enables the part to function as a “one wire current source;” one side of the LED string can be returned to ground anywhere, allowing a simpler one wire LED connection. Traditional LED drivers use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string. The high switching frequency allows the use of tiny inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. Few external ponents are needed: open-LED protection and the Schottky diode are all contained inside a low profile 3mm × 2mm DFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Drives Up to Ten White LEDs from a 3V Supply High Side Sense Allows “One Wire Current Source” Internal Schottky Diode One Pin Dimming and Shutdown 80:1 True Color PWMTM Dimming Range 42V Open LED Protection 1MHz Switching Frequency ±5% Reference Accuracy VIN Range: 2.5V to 12V Requires Only 2.2µF Output Capacitor Low Profile 8-Lead DFN Package (3mm × 2mm × 0.75mm) APPLICATIONS - - - - - Cellular Phones PDAs, Handheld puters Digital Cameras MP3 Players GPS Receivers TYPICAL APPLICATION Li-Ion Driver for Ten White LEDs SHUTDOWN AND DIMMING CONTROL CTRL EFFICIENCY (%) VIN 3V TO 5V 22µH SW GND 1µF VIN LT3591 LED 2.2µF CAP RSENSE 10Ω 80 Conversion Efficiency VIN = 3.6V 10 LEDs 10 LED CURRENT (m...