1.2MHz White LED Step-Up Converters with Built-In Schottky in ThinSOT

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 LT3465 has internal soft-start.

The LT3465 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 LT3465 and LT3465A are available in low profile (1mm) 6-lead SOT-23 (ThinSOT™) packages.

Applications

* Cellular Phones

* PDAs, Handheld Computers

* Digital Cameras

* MP3 Players

* GPS Receivers

* 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