The AAT3103 is a constant frequency charge-pump based current-source white LED driver capable of driving one to three LEDs up to 30mA, each. The charge pumps automatically switch between 1x mode and 2x mode to maintain the highest efficiency and optimal LED current accuracy and matching. A low external parts count (one 1µF flying capacitor, two small 1µF capacitors at IN and OUT and one current setting resistor) makes the AAT3103 ideally suited for small battery-powered applications. The AAT3103-1/-2 uses AnalogicTech's Simple Serial Control™ (S²Cwire™) interface to enable, disable, and program the LED driving current. The AAT3103-4 employs a Pulse Width Modulation (PWM) signal with up to 50kHz frequency, 10% to 100% duty cycle to program the LED current. A low-current shutdown feature disconnects the load from IN and reduces quiescent current to less than 1µA. Built-in soft-start circuitry prevents excessive inrush current during start-up. Integrated short circuit and thermal protection circuitry protects the device from damage. The AAT3103 is available in a 2x2.1mm thermally enhanced Pb-free 10-lead SC70JW-10 package.