LTC3453

Cell phones and PDAs of LTC3453 are approaching the limit for small form factors, but their feature sets are growing with new functions such as built-in cameras and even video cameras. The initial in-phone cameras were basic, low resolution devices with little in the way of usable flash capability. However, cell phone camera resolutions have improved and sophisticated flash technology is expected to keep pace.

There are two flash technologies used in digital still cameras. The first uses a Xenon flash lamp to provide a very short, high lumen flash with excellent spectral characteristics. LTC offers Xenon photoflash solutions that are simple, compact and efficient (see Design Note 345).

The second flash technology of LTC3453 uses LEDs. LED solutions hold the upper hand when simplicity and space is at a premium and they are the only choice when 'torch' or video-mode lighting is required. LED flash units fit into spaces where even the smallest Xenon photoflash cannot. Until recently, LEDs could not compete with Xenon solutions in light output and spectral performance, relegating them to the realm of low resolution (sub 1 megapixel) cameras. However, recent (>10*) performance improvements have made LEDs an attractive solution for the now popular 1 megapixel and higher cell phone cameras.

Linear Technology of LTC3453 offers many simple and extremely compact solutions for driving the latest high-light-output LEDs, including Lumileds Luxeon Flash LEDs. These LEDs are up to 12 times brighter than conventional LEDs