DESCRIPTION

AIC1647 is a fixed frequency step-up DC/DC converter designed to drive white LEDs with a constant current to provide backlight in handheld devices. Series connection of the LEDs provides identical LED currents resulting in uniform brightness. This configuration eliminates the need for ballast resistors. Low 95mV feedback voltage minimizes power loss in the current setting resistor for better efficiency.

FEATURES

• 1.2MHz Fixed Frequency Current-Mode PWM

Operation.

• Efficiency Up to 84 at VIN=4.2V, 3LEDs,

ILED=20mA

• Drives Up to 6LEDs in series

• Low Supply Current: 70µA

• Matches LED Current

• Require Tiny Inductors and Capacitors

• Tiny SOT23-5 Package

APPLICATIONS

• Cellular Phones

• PDAs

• Digital Still Cameras

• Handheld Devices

• White LED Display Backlighting