The SM8134A is a charge pump type white LED driver. It can drive 1 to 4 backlight white LED connected in parallel and 1 flash white LED, making the device ideal for camera-equipped cellular phones. The charge pump switches between x1 to x1.5 boost mode in response to LED drive current requirements to extend battery life to the maximum. The boost switching occurs in response to the drive current of all the connected LED and thus supports variations in LED forward-bias voltage drop (VF). Each LED drive current is controlled by a 5-channel LED drive current control circuit. The backlight LED drive current and ON/OFF control, and flash LED drive current and ON/OFF control are all set by 3-wire serial interface data input. Also, an under voltage lockout (UVLO) circuit is built-in to prevent incorrect operation when the battery voltage drops.