AAT2869

PRODUCT DATASHEET AAT2869 SystemPowerTM General Description The AAT2869 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 AAT2869 is capable of driving 4 white LEDs at a total of 124mA 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 IN and OUTCP) makes the AAT2869 ideally suited for small battery-powered applications. The fade-in/fade-out feature makes backlight turn-on/turn-off more visual comfortable. The AAT2869 also includes two 150mA low, drop-out linear regulators as additional power supplies for display and related camera power. The LDO voltage is also programmable. AnalogicTech’s Advanced Simple Serial Control™ (AS2Cwire™) serial digital input is used to enable, disable and set the maximum LED current to one of 32 levels for the LEDs, to enable/disable the LDOs, and to set the LDO's output. The programmable LED current ranges from 31mA to 0.4mA. Each output of the AAT2869 is equipped with built-in protection for short-circuit and auto-disable for load short-circuit conditions. The soft-start circuitry prevents excessive inrush current at charge pump start-up and mode transitions. The AAT2869 is available in the Pb-free, space-saving TQFN3.0x2.2-18L package, and operates ov...