The SM8133B is a charge pump type white LED driver. It can drive 1 to 6 backlight white LED connected in parallel and 1 flash white LED. The output voltage circuit has a 3.0V LDO (Low Dropout Regulator), 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 7-channel LED drive current control circuit. The 6 backlight channels can be subdivided into 2 groups, with each group having independent dimming and lighting control. The backlight grouping, backlight LED drive current and ON/OFF control, flash LED drive current and ON/OFF control, and LDO output ON/OFF control are all set by 3-wire serial interface data input. Also, the RESETB pin can be connected to the microcontroller supply for a system-wide shutdown function.