Inductive boost dc/dc converter powers series-connected white LEDs - Embedded.com

Inductive boost dc/dc converter powers series-connected white LEDs

Advanced Analogic Technologies (AnalogicTech) announced the AAT1231, a high-frequency, high-efficiency inductive boost dc-to-dc converter for controlling white LEDs in portable systems operating from single-cell Li-Ion/polymer batteries. Delivering 50 mA up to 24 V, this device can drive up to six white LEDs in series or up to 12 white LEDs in a parallel/series configuration using the company's digital Simple Serial Control (S2Cwire) single-wire interface.

LED output current on the AAT1231 is controlled in 16 linear steps. By changing the feedback voltage with the SEL pin, designers can extend the output voltage another 16 levels. This allows designers to “set and forget” the output across a total of 26 steps (after overlap) from 7.5% to 100%. Digital control improves display readability by providing constant flicker-free LED output.

The AAT1231's 2-MHz switching frequency provides fast response to load transients and permits the use of small external components including a 2.2-μH inductor. The part delivers overall efficiency up to 82%. The AAT1231 also adds a true load disconnect feature which completely isolates the load from the power source. By reducing leakage current to less than 1 μA, this function extends battery life and system standby time.

Specified over the -40°C to +85°C temperature range, the AAT1231 is immediately available in a Pb-free, 12-pin TSOPJW package. The device sells for $0.94 each in 1000-piece quantities. For more information, visit the AnalogicTech Web site at www.analogictech.com.

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