AAT3142

The AAT3142 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 device produces current levels up to 30mA on each of its three current source outputs to drive various arrangements of LEDs from a 2.7V to 5.5V input. Outputs may be operated individually or in parallel for driving higher- current LEDs. A low external parts count (two 1F flying capacitors and two small 1F capacitors at V_IN and CP) make the AAT3142 ideally suited for small battery-powered applications.

AnalogicTech's Simple Serial Control™ (S²Cwire™) digital input is used to enable, disable, and set the LED drive current with a 32-level logarithmic scale LED brightness control. The AAT3142 has a thermal management system to protect the device in the event of a short-circuit condition at an 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. In shutdown mode, the device disconnects the load from V_IN and reduces quiescent current to less than 1A. The AAT3142 is available in the very small, Pb-free 12-pin TSOPJW package.