The LM2755 is a charge-pump-based, constant current LED driver capable of driving 3 LEDs with a total output current up to 90mA. The diode current waveforms of each LED can be trapezoidal with timing and level parameters (rise time, fall time, high level, low level, delay, high time, low time) programmed via an I2 C compatible interface. The 32 brightness levels found on the LM2755 are exponentially spaced (as opposed to linearly spaced) to better match the response of the human eye to changing brightness levels.
The LM2755 evaluation board is designed to display the functionality of the LM2755. With a charge-pump-based boost converter, and three highly programmable constant current LED drivers, the LM2755 is ideal for driving RGB LEDs. The timing and level parameters (rise time, fall time, high level, low level, delay, high time, low time) of each LED can be programmed to create a large number of different color and lighting schemes. The LM2755 is available in TI's 18-bump µ SMD package.