The LT3465/LT3465A are step-up DC/DC converters designed to drive up to six LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents and eliminates the need for ballast resistors. These devices integrate the Schottky diode required externally on competing devices. Additional features include output voltage limiting when LEDs are disconnected, onepin shutdown and dimming control. The LT3465ES6#TRPBF has internal soft-start.
The LT3465ES6#TRPBF switches at 1.2MHz, allowing the use of tiny external components. The faster LT3465A switches at 2.4MHz. Constant frequency switching results in low input noise and a small output capacitor. Just 0.22µF is required for 3-, 4- or 5-LED applications.
The LT3465ES6#TRPBF and LT3465A are available in low profile (1mm) 6-lead SOT-23 (ThinSOT™) packages.
Feature
Inherently Matched LED Current
Drives Up to Six LEDs from a 3.6V Supply
No External Schottky Diode Required
1.2MHz Switching Frequency (LT3465)
2.4MHz Switching Frequency Above AM Broadcast Band (LT3465A)
VIN Range: 2.7V to 16V
VOUT(MAX) = 30V
Automatic Soft-Start (LT3465)
Open LED Protection
High Efficiency: 81% (LT3465) 79% (LT3465A) Typical
Requires Only 0.22µF Output Capacitor
Low Profile (1mm) SOT-23 Packaging
Applications
Cellular Phones
PDAs, Handheld Computers
Digital Cameras
MP3 Players
GPS Receivers