AAT3131

The AAT3131 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 maximize efficiency for white LED applications. The device can be used to produce current levels up to 20mA in three of its outputs, and 30mA in one of its outputs to drive LEDs from a 2.7V to 5.5V input. Outputs may be operated individually or paralleled for driving higher-current LEDs. Low external parts counts (two 1F flying capacitors and two small 1F capacitors at V_IN and OUT) make the AAT3131 ideally suited for small battery-powered applications. AnalogicTech Simple Serial Control(S²Cwire) interface is used to enable, disable, and set the LED drive current in two groups: the three 20mA outputs and the single 30mA output with multiple level logarithmic scales. The AAT3131 has a thermal management system to protect the device in the event of a short circuit condition at the output pin. Built-in soft-start circuitry prevents excessive inrush current during start-up. A high charge pump switching frequency enables the use of very small external capacitors. A low current shutdown feature disconnects the load from V_IN and reduces quiescent current to less than 1A. The AAT3131 is available in very small 12-pin TSOPJW package.