NCP5050 pdf,datasheet

4.5 W Flash White LED Boost Driver

The NCP5050 is a high powered fixed frequency PWM boost
converter optimized for constant current applications such as driving
high-powered white LEDs. This device has been designed with
high-efficiency for use in portable applications and is capable of
driving up to 5 high power LEDs in series for camera flash or
flashlight (torch) applications. To support the need of driving the
LEDs in a high current pulse mode for flash as well as a continuous
mode for focus or torch, a control pin and support circuitry is
incorporated which allows the user to program two LED currents. The
both output current are fully configurable via the use of 2 external
resistors and this average current can be reduced by applying a PWM
signal to the CTRL pin up to 50 kHz.