The LM3530, a member of National’s PowerWise energy-efficient product family, drives up to 11 high-current LEDs in series, illuminating larger displays in portable media devices such as smartphones. The LM3530 is offered in a 12-bump micro SMD package measuring 1.615×1.215×0.425mm.
LM3530 current-mode boost converter can supply up to 29.5mA of power to 11 white LEDs from a single-cell Lithium-Ion battery. A wide degree of programmability via an I2C compatible interface enables the designer to adjust to lighting effects such as fading, external ambient conditions and lighting level, as well as brightness and image performance.
The LM3530’s programmable ambient light response along with a separate pulse-width modulation (PWM) dimming input, enable the backlight LED driver to intelligently determine lighting requirements and choose from various dimming options, optimizing the light output for the given conditions. Logarithm and linear LED brightness mapping provides flicker-free dimming. A fixed-frequency, 500 kHz boost converter provides high efficiency over the LED current range.
Priced at $1.99 in 1,000-unit quantities, the LM3530 brings power savings to the serial implementation of large display backlighting. For parallel charge pumps, National will offer a product with a similar feature set, in October 2009.