AnalogicTech Offers I²C-Based LED Driver IC For Handset Lighting
Advanced Analogic Technologies, Inc. (AnalogicTech) announced the AAT2860, a new I²C-based Lighting Management Unit (LMU) that integrates up to seven LED drivers and three Low Dropout (LDO) linear regulators in a single IC. By offering these power functions in a variety of configurations, the new IC is said to offer designers a single compact lighting solution for a wide variety of high performance camera phones.
"Most smart phones today require some combination of backlight LED drivers for a main display, sometimes additional LED drivers for a smaller sub-display, one or more flash LED drivers, and LDOs to power the embedded camera," said Phil Dewsbury, Product Line Director at AnalogicTech. "By rolling all these functions in various configurations into a single IC, the AAT2860 allows designers to minimize component count, board space and cost whether they are building a high end PDA-type phone with a single large display or a traditional clamshell design with two displays."
Optimized for single-cell Lithium-ion/polymer systems, the AAT2860 operates across a 2.7 to 5.5V input voltage range. A tri-mode charge pump drives up to seven LEDs in multiple backlight and flash configurations.
The new LMU is initially available in two basic configurations. The AAT2860-1 is configured into either 7 LED drivers for a main display or 4 for a main display and three for a sub-display. The AAT2860-2 offers six LED drivers for a main display and one flash driver or four for a main display, two for a sub display and one flash driver. Other configurations are available upon request.
The current level for each LED is enabled, disabled and set via an I²C compatible serial interface. Backlight LEDs can be programmed across 32 discrete levels from 0.5 to 31mA. To ensure uniform display brightness, current matching is better than 3%.
Flash LEDs are programmable across 16 levels up to 300mA. Current matching for the flash LEDs is better than 5%. To protect the flash LEDs from thermal damage, the AAT2860 also includes a programmable safety timer, which will automatically terminate the flash pulse in the event of a software failure.
The AAT2860 also features three low-noise, low-dropout (LDO) linear regulators. Each LDO can deliver up to 300mA load current with 150 mV dropout. Ground pin current is 80µA. Each output is programmable via I²C from 1.5 to 3.0-V. The AAT2860 also features automatic soft start and integrated thermal protection.
Qualified across the -40 to +85°C temperature range, the AAT2860 is available in a Pb-free, 24-pin TQFN34 package. The device sells for $2.08 in 1K quantities.
