AnalogicTech’s Introduces New Inductive Boost dc-dc Converter
Advanced Analogic Technologies Inc. (AnalogicTech) announced the AAT1231, a high frequency, high efficiency inductive boost dc-dc converter for controlling white LEDs in portable systems operating from single-cell lithium-ion/polymer batteries. Delivering 50mA up to 24V, this new device is capable of driving up to six white LEDs in series or up to 12 white LEDs in a parallel/series configuration using AnalogicTech's digital Simple Serial Control™ (S2Cwire™) single-wire interface.
"The former de facto standard PWM techniques to control series-connected LEDs produce variations in current and therefore LED brightness. In addition, PWM control methods consume microcontroller processing resources, require GPIO interfaces, and demand a large number of additional components," said Adolfo Garcia, Product Line Director for AnalogicTech. "With the AAT1231, designers can use a single wire to digitally control the LEDs, which provides flicker-free light output, reduces MCU clock cycles, saves GPIO resources, and builds a complete solution with fewer components."
LED output current on the AAT1231 is controlled using AnalogicTech's S2Cwire interface 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 high 2MHz switching frequency provides fast response to load transients and permits the use of small external components including a 2.2µH inductor. The AAT1231 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 1µA, this function extends battery life and system standby time. The AAT1231 also offers a wide variety of standard protection features, including integrated soft-start, current limit, over-temperature, and over-voltage protection.
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.
