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Updated: July 8th, 2008 05:26 PM CDT

National Semiconductor Introduces World's Smallest, Fully Integrated Flash LED Driver

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via PRNewswire

SANTA CLARA, Calif., Oct. 31 /PRNewswire-FirstCall/ -- National Semiconductor Corporation (NYSE: NSM), the worldwide leader in powermanagement technology, today introduced the world's smallest fully integrated flash light-emitting diode (LED) driver. The LM2754, featuring low inputnoise, adjustable output power control and automatic LED shutdown, delivers upto an 800 mA load in handheld applications.

Many of today's cellular phones feature built-in digital cameras capable of both high-resolution still and video images. Gains in camera technologie shave created the need for a high-power white-light source for camera useindoors or in dim ambient light. White LEDs, already popular for backlighting color displays, have emerged as the flash light source in camera phones. National's LM2754 charge-pump-based, high current, flash LED driver boasts aunique circuit design that enables several exclusive system-level features,such as reduced noise spikes on the input and adjustable output power control to prevent battery drain. The LM2754 also features automatic LED shutdown to avoid excessive heat from the LED if it stays on longer than it should. In addition, National's LM2754 can effectively drive one, two, three or four LEDsat the same time. This makes the LM2754 well-suited for both multiple- and single-die flash LED technologies in cell phone cameras.

National's LM2754 will be shown in National's booth in hall A4, stand #506at the Electronica trade show in Munich , Germany , from November 14-17.

Technical Features of National's LM2754 Flash LED Driver

National's LM2754 drives up to an 800 mA load with an input voltage as lowas 3.0V. A unique circuit design enables several exclusive technical features.

National's LM2754 reduces noise spikes on the input battery, a common problem when pulling high flash currents from the battery. To drive a highoutput current in a cell phone design for example, switched capacitor boosts must pull an even higher current from a portable device's battery. Thiscauses large current spikes at the battery terminals that interfere with sensitive RF and analog circuitry also supplied by the battery. In typical high-power boost converters, the input current and associated noise levels cancause the mobile device to be knocked off of the network, resulting in a dropped call. National's LM2754 features unique circuitry that draws currentfrom the battery using a graduated and controlled regime, resulting insignificantly lower peak current levels on the input line.

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