LM5050-1: What the difference of LM5050-1 and LN5050-2 ?

Dear all:

       What the difference of LM5050-1 and LN5050-2？　

       I found that Lm5050-1 is power supply from MOS. Lm5050-2 is internal power supply；what difference of the two type power supply?

       and LM5050-2 is the upgrade version of lm5050-1？Why is their power supply not on the same side?

　　many thanks;