AAT3121

DATA SHEET AAT3121 High Efficiency 1.5X Fractional Charge Pump for White LED Applications General Description The AAT3121 is a low noise, constant frequency charge pump DC/DC converter that uses fractional (1.5X) conversion to increase efficiency in white LED applications. With input voltages ranging from 2.7V to 5.5V, the device can produce an output current of up to 120mA. A low external parts count (two 1µF flying capacitors and two small bypass capacitors at VIN and OUT) makes the AAT3121 ideally suited for small battery-powered applications. Skyworks' Simple Serial Control™ (S2Cwire™) interface is used to enable, disable, and set the LED drive current with a 32-level logarithmic scale LED brightness control. The AAT3121 has a thermal management system to protect the device in the event of a short-circuit condition on any of the output pins. Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small exter...