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Power chip pumps up handset flashes

An Advanced Analogic Technologies product story

Edited by the Electronicstalk editorial team Nov 29, 2005

By combining 600mA of output current with a digital serial control interface, the AAT3172 offers unprecedented ability to deliver optimal LED flash performance across a wide variety of applications.

Advanced Analogic Technologies has introduced a high output, high efficiency current-output charge pump IC for white LED flash applications.

Cellphone designers embedding higher performance cameras in their next generation products need ICs capable of delivering high power output with excellent control in a small package.

By combining 600mA of output current with a digital serial control interface, the AAT3172 gives designers unprecedented ability to deliver optimal LED flash performance across a wide variety of flash applications.

The device supplies its output current across dual regulated current sinks.

Each LED channel can be programmed in 32 steps with a single GPIO output through AnalogicTech's AS2Cwire (Advanced Simple Serial Control) interface.

The AAT3172 is a trimode device that maximises efficiency by combining a load switch (1x), fractional (1.5x) and doubling (2x) capability with an internal sensing circuit to match output to LED requirements.

The 1x and 1.5x modes allow minimum current draw from the battery during lower LED current operations such as torch or movie light, which operates for a much longer period of time than the flash mode.

Dual current sinks allow system designers to use single or dual (separate cathode) flash LED configurations.

The device's 32-step single wire interface smoothes transitions and gives designers flexible control of brightness in flash or other lighting modes.

The interface can also be programmed to provide a regulated voltage instead of current, for additional system loads.

The AAT3172 requires just four external components: two 1.0uF ceramic capacitors for the charge pump flying capacitors, one 1.0uF capacitor for C(in), and one for C(out).

The device also features a thermal management system and built-in soft-start circuitry, and is immediately available in a Pb-free, thermally enhanced, 12-pin 3 x 3mm TDFN package.