• 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: 70uA
• Matches LED Current
• Require Tiny Inductors and Capacitors
• Tiny SOT23-5 and TSOT23-5 Packages

• Cellular Phones
• PDAs
• Digital Still Cameras
• Handheld Devices
• White LED Display Backlighting

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.
AIC1647 is a step-up PWM converter, which includes an internal N-channel MOSFET switch for high efficiency. The high switching frequency, 1.2MHz, allows the use of tiny external components, saves the layout space and cost.
AIC1647 is available in space-saving, SOT23-5 and TSOT23-5 packages.