LT3498

The LT3498 is a dual output boost converter featuring a 2.3MHz PWM LED Driver and PFM OLED Driver. It includes an internal power switch and Schottky diode for each driver. Both converters can be independently shut down and modulated. This highly integrated power solution is ideal for dual display electronic devices.

The 2.3MHz step-up converter is designed to drive up to six white LEDs in series from a Li-Ion cell. 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. Traditional LED drivers use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string.

The PFM OLED driver is a low noise boost converter that features a novel control technique.* The converter controls power delivery by varying both the peak inductor current and switch off time. This technique results in low output voltage ripple, as well as, high efficiency over a wide load range. The off time of the switch is not allowed to exceed a fixed level, guaranteeing a switching frequency that stays above the audio band.

Applications

• Cellular Phones
• PDAs, Handheld Computers
• Digital Cameras
• MP3 Players
• GPS Receivers