High-Current Charge Pump Targets Photo-Flash LED Drivers

The AAT3170 from Advanced Analogic Tech is a high-output-current, high-efficiency, low-noise, low-profile charge pump dc-dc converter that is well suited for multifunction LED photo-flash applications. Running on a 2.7- to 5.5-V supply, the device's dual charge pump can deliver 600 mA of output current. Two current-controlled paths are available for users of dual flash LEDs that prefer current matching. Each LED channel can be programmed in 32 steps with one GPIO output through the AS²Cwire (Advanced Simple Serial Control) interface. The tri-mode (1X, 1.5X, 2X) operation of the internal charge pump delivers excellent power efficiency for both flash and movie modes. This and a low external parts count (no inductors are needed) make the AAT3170 a good fit for small, battery-powered devices.

The IC has a thermal management system to protect the device in the event of a short circuit at the output pin. Built-in soft-start circuitry prevents excessive in-rush current during start-up. The shutdown feature disconnects the load from V\[subscript\]IN and reduces quiescent current to less than 1.0 µA. Rated temperature range is -40°C to +85°C. The AAT3170 comes in a lead-free, thermally enhanced, 12-pin 3- by 3-mm TDFN package.