AAT3156

www.DataSheet4U.com AAT3156 High Efficiency 1X/1.5X/2X Charge Pump For White LED Applications General Description The AAT3156 is a low noise, constant frequency charge pump DC/DC converter that uses a trimode load switch (1X), fractional (1.5X), and doubling (2X) conversion to maximize efficiency for white LED applications. The AAT3156 is capable of driving six-channel LEDs at a total of 180mA from a 2.7V to 5.5V input. The current sinks may be operated individually or in parallel for driving higher-current LEDs. A low external parts count (two 1µF flying capacitors and two small 1µF capacitors at VIN and VOUT) make this part ideally suited for small battery-powered applications. AnalogicTech's AS2Cwire™ (Advanced Simple Serial Control™) serial digital input is used to enable, disable, and set current for each LED with a 16-level logarithmic scale plus four low-current settings down to 50µA for optimized efficiency, with a low housekeeping current of only 50µA. Each output of the AAT3156 is equipped with builtin protection for VOUT short circuit and auto disable for LED failure condition. Built-in soft-start circuitry prevents excessive inrush current during start-up. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1µA. The AAT3156 is available in a space-saving, thermally-enhanced 16-pin 4x4mm QFN package. Features ChargePump™ VIN Range: 2.7V to 5.5V Fully Programmable Current with Single ...