The KF9907 is a step-up DC/DC converter specifically designed to drive up to 5 series white LEDs with constant current. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminates the need for ballast resistors. The KF9907 switches at 1.4MHz， allowing the use of tiny external components. A low 0.25V feedback voltage minimizes power loss in the current setting resistor for high efficiency. The OVP pin monitors the output voltage and turns off the converter whenever the LEDs are open.
The KF9907 is available in low profile SOT-23-6 package.
Features
Inherently Matched LED Current
High Efficiency:82%
Drives Up to Five LEDs from 2.2V Supply
17V Over Voltage Protection
Fast 1.4MHz Switching Frequency
Requires only 1μF Output Capacitors
SOT-23-6 Package
Application
Communication equipment
White LED Backlight Display for PDA
Pocket PC
Handheld Devices
Cellular Phones
White LED display backlighting