This document introduces a high power LED camera flash solution for cell phone applications. The solution uses LED flash lights, which are small and efficient, and can meet the various needs of cell phones for flash lights.
The document addresses the need for small form factor high-power LED drivers for cell phones with built-in cameras. It highlights that while Xenon lamps offer high lumen output, LEDs are preferred for their simplicity and space efficiency, particularly for 'torch' or video-mode lighting.
Linear Technology offers four specific devices to solve constant-current driving problems: the LTC3216 charge pump, the LTC3453 buck-boost regulator, the LT1618 constant-current/constant-voltage converter, and the LT3479 boost regulator. The text details circuit configurations for driving Lumileds LXCL-PWF1 and LXCL-PWF2 LEDs with these drivers.
| LTC3453 LED flash current | up to 500mA |
|---|---|
| LTC3216 LED flash current | 800mA |
| LT3479 LED flash current (PWF2) | up to 700mA |
| LTC3453 efficiency | 90% |
The LT3479 boost regulator can provide up to 700mA constant-current flash to the PWF2.
LED solutions are preferred when simplicity and space are at a premium, and they are required for 'torch' or video-mode lighting.