Inductive Boost DC-DC Converter Powers Series-Connected White LEDs

July 26, 2006
Advanced Analogic Technologies’ AAT1231 high-frequency, high-efficiency inductive boost dc-dc converter controls white LEDs in portable systems operating from single-cell lithium-ion/polymer batteries. Delivering 50 mA up to 24 V, it can drive up to six w

Advanced Analogic Technologies’ AAT1231 high-frequency, high-efficiency inductive boost dc-dc converter controls white LEDs in portable systems operating from single-cell lithium-ion/polymer batteries. Delivering 50 mA up to 24 V, it 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 (S(2)Cwire) single-wire interface.

Traditional pulse-width modulation (PWM) techniques used to control series-connected LEDs can produce variations in current and therefore LED brightness. In addition, PWM control methods consume microcontroller processing resources, require general-purpose I/O interfaces, and demand additional components.

LED output current on the AAT1231 is controlled using the S(2)Cwire interface in 16 linear steps. By changing the feedback voltage with the SEL pin, designers can extend the output voltage another 16 levels. This lets designers “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 flicker-free LED output.

The AAT1231’s high 2-MHz switching frequency provides fast response to load transients and permits the use of small external components, including a 2.2-µH inductor. Overall efficiency can be up to 82%. A true load disconnect feature 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 from –40°C to 85°C, the AAT1231 is immediately available in a lead-free, 12-pin TSOPJW. The device costs $0.94 each in 1000-piece quantities.

AnalogicTech
www.analogictech.com

Sponsored Recommendations

Highly Integrated 20A Digital Power Module for High Current Applications

March 20, 2024
Renesas latest power module delivers the highest efficiency (up to 94% peak) and fast time-to-market solution in an extremely small footprint. The RRM12120 is ideal for space...

Empowering Innovation: Your Power Partner for Tomorrow's Challenges

March 20, 2024
Discover how innovation, quality, and reliability are embedded into every aspect of Renesas' power products.

Article: Meeting the challenges of power conversion in e-bikes

March 18, 2024
Managing electrical noise in a compact and lightweight vehicle is a perpetual obstacle

Power modules provide high-efficiency conversion between 400V and 800V systems for electric vehicles

March 18, 2024
Porsche, Hyundai and GMC all are converting 400 – 800V today in very different ways. Learn more about how power modules stack up to these discrete designs.

Comments

To join the conversation, and become an exclusive member of Electronic Design, create an account today!