AnalogicTech – High-current charge pump simplifies dual flash / movie mode designsApr 5 2006 - Semiconductors [More Semiconductors Articles]
Offering ease of design and enhanced functionality, a high-current, high-efficiency charge pump for multi-function LED applications, has been unveiled by AnalogicTech.
Recognising that a serial bus is a powerful tool for driving LEDs – albeit a method that requires the designer to take time to learn how to program it and develop a solution - the AAT3174 facilitates designers who want to quickly and easily develop a solution that supports both flash and movie mode operation and importantly, can move between the two modes using a simple on/off toggle switch, says the company.
The device dramatically simplifies the design of applications supporting both flash and movie modes by allowing designers to control the LEDs via either the company’s Simple Serial Control (S2Cwire) interface or by the RSET pin. This novel capability also allows designers to support current levels as high as 800mA with an external resistor.
The AAT3174 also helps maximise 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 1uF 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 extensive 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 -40C to +85C temperature range, the AAT3174 is available in a Pb-free, 12-pin 3mm x 3mm TDFN package, says the comapny.More news from Analogictech