AnalogicTech痴 I2C-based LED driver IC offers total handset lighting solution
(Technology News, 07 Jul 2008 )
Advanced Analogic Technologies Inc. (AnalogicTech), a developer of power management semiconductors for mobile consumer electronic devices, 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 offers designers a single compact lighting solution for a wide variety of high performance camera phones.
Multiple Configurations Optimized for single-cell Lithium-ion/polymer systems, the AAT2860 operates across a 2.7V 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 mA to 31 mA. To ensure uniform display brightness, current matching is better than 3 percent.
Flash LEDs are programmable across 16 levels up to 300 mA. Current matching for the flash LEDs is better than 5 percent. 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 300 mA load current with 150 mV dropout. Ground pin current is 80 オA. Each output is programmable via I2C from 1.5 to 3.0-V.