特点
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)
典型应用
典型应用
描述
The LT3591 is a fixed frequency step-up DC/DC converter speci? cally 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 components are needed: open-LED protection and the Schottky diode are all contained inside a low pro? le 3mm × 2mm DFN package.