AAT3122

AAT3122 High Efficiency 1X/1.5X Fractional Charge Pump for White LED Applications General Description The AAT3122 is a low noise, constant frequency charge pump DC/DC converter that uses a dual mode load switch (1X) and 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 AAT3122 ideally suited for small battery-powered applications. AnalogicTech's 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 AAT3122 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 external capacitors. A low shutdown current feature disconnects the load from VIN and reduces quiescent current to less than 1µA. The AAT3122 provides a single current source output that can be used to drive up to six LEDs at 20mA each. The AAT3122 is available in a Pb-free TSOPJW-12 package. Features • • • • • • • • • • • • • • ChargePump™ VIN Range: 2.7V to 5.5V