Description
Description
The LT3465/LT3465A devices are step-up DC/DC converters designed to drive up to six LEDs in series from a Li-Ion cell. Connecting the LEDs in series provides identical LED currents and eliminates the need for ballast resistors. These devices have the Schottky diode required externally on competing devices built in. Additional features include output voltage limiting when LEDs are disconnected, one-pin shutdown and dimming control. The LT3465 has internal soft-start.
The LT3465 switches at 1.2 MHz, allowing the use of tiny external components. The faster LT3465A switches at 2.4 MHz. Constant frequency switching results in low input noise and a small output capacitor. Just 0.22 µF is required for 3-LED, 4-LED or 5-LED applications.
The LT3465 and LT3465A are available in low profile (1 mm) 6-lead SOT-23 (ThinSOT™) packages.
Characteristics
• Inherently matched LED current
• Drives up to six LEDs from a 3.6-V supply
• No external Schottky diode required
• 1.2-MHz switching frequency (LT3465)
• 2.4-MHz switching frequency above AM broadcast band (LT3465A)
• Automatic soft start (LT3465)
• Open LED protection
• High efficiency: 81% (LT3465) 79% (LT3465A) typical
• Requires only 0.22-µF output capacitor
• Low profile (1 mm) SOT-23 packaging
