National semiconductor white LED driver reduces power consumption by 55%

National Semiconductor Corporation Ns (National Semiconductor; NS) announced the launch of a flexible control screen backlight brightness of small white LED driver. National Semiconductor PowerWise series high efficiency energy chip LM3530 boost converter for driving high current LED as high as 11 series, backlighting power sufficient for portable multimedia electronic products such as intelligent mobile phone screen.

LM3530 LED driver using ambient light sensing algorithm and advanced control technology for video content should adjust the backlight, can not only ensure that the picture is clear and bright, but also can reduce the power consumption, a reduction of up to 55% backlight system of actual power consumption than the general brightness invariant constant.

National semiconductor has 3.5 inch iPod touch screen backlight system power consumption test, which were divided into two groups, one group with national semiconductor LM3530 LED drive, while the control group did not use this driver. The videos used in the test are multimedia videos that can be easily downloaded from the Internet, such as the test of a TV series and a movie trailer. The test results show that the LM3530 backlight system consumes less power, and the actual power consumption is reduced by 43% and.

The national semiconductor LM3530 current mode boost converter can use a lithium battery for 11 white LED to provide up to 29.5mA drive current. System design engineers can set up a variety of different functions through the I2C interface, such as the gradual darkening, the external environment and the output of light, as well as brightness and image effects.

Another advantage of the LM3530 chip can be set the ambient light reaction time, but also have independent PWM dimming input function, so this LED backlight driver can flexibly set the backlight brightness according to actual conditions required, and then make a different degree of dimming control, so as to provide the light output with the most suitable.

In addition, this chip through the logarithmic function and linear LED brightness mapping technology to ensure that when the flicker does not appear. The boost converter uses a fixed 500kHz frequency operation, so as long as the LED current does not exceed the specified range, efficiency can be maintained at a high level. LM3530 chip using 12 pin micro SMD package, the size of only 1.615mm x 1.215mm x 0.425mm.

Series LED configuration of large screen display backlight system as long as the use of LM3530 chips, you can reduce system power consumption. As for the use of parallel current screen, the United States National Semiconductor will be launched in October 2009 with another feature similar products.