AnalogicTech LED Driver Supports Flash and Movie Lighting
Advanced Analogic Technologies Inc. now offers the AAT3174, a high current charge pump for multi-function LED applications. This new device simplifies the design of applications supporting both flash and movie modes by allowing designers to control the LEDs via either AnalogicTech's Simple Serial Control™ (S²Cwire™) interface or by the Rset pin. This capability also allows designers to support current levels as high as 800mA with an external resistor.
"A serial bus offers a powerful tool for driving LEDs, but it also requires that the designer take time to learn how to program it and develop a solution," notes Kin Shum, Product Line Director for AnalogicTech. "Designers who want to quickly and easily develop a solution that supports both flash and movie mode operation can use the AAT3174 to move between the two modes using a simple on/off toggle switch."
The AAT3174 also helps maximize power efficiency during extended torch mode operations by using a tri-mode charge pump that combines 1X, 1.5X, and 2X operation modes with an internal sensing circuit. This allows the AAT3174 to deliver power more efficiently than a simple voltage doubling (2X) charge pump.
Designed for small-footprint portable applications, the AAT3174 requires only four external capacitors (two 1µF flying capacitors and two small bypass capacitors on Vin and Vout), plus a resistor to program the maximum regulated output current. The device also offers protection circuitry, including a thermal management system which protects the AAT3174 in the event of a short-circuit condition at the output pin. In addition, integrated soft-start circuitry protects the device from excessive inrush current during start-up by disconnecting the load from Vin and reducing quiescent current to less than 1µA.
Specified over the -40°C to +85°C temperature range, the AAT3174 is available in a Pb-free, 12-pin 3x3mm TDFN package. The device sells for $1.82 in 1000-unit quantities.
