You have successfully added from to your part list.
BD9421F is high efficiency driver for white LED. This is designed for large sized LCD. BD9421F is built-in DCDC converters that supply appropriate voltage for light source. BD9421F is also built-in protection function for abnormal state such as OVP: over voltage protection, OCP: over current limit protection of DCDC, SCP: short circuit protection, open detection of LED string. Thus this is used for conditions of large output voltage and load conditions.