Mystery International Rectifier part

[finite_state_machine]

I have a bunch of these parts from a grab bag, and I can't seem to find any information about them. They're in a sort of power MOSFET/voltage regulator package, and they have the following written on them:

50012LB
I*R 937C
84 49 <- I believe this is the date code, they're not all the same.

I've done my best to find datasheets for this, but no luck at all. I'm not even sure which part is the model number, so any help you can offer would be much appreciated .

 

[CocaCola]

50012LB is the part number
937C is the assembly date = year 1999 or 2009 week 37 line C
84 49 is the lot number

Beyond that you will have to dig further, seems like it might be an OEM part number, have you tried emailing IR?

I came across one post (sorry didn't save it) that suggested that it was a FET, the only difference was the last letter in the part number...

 

[shrtrnd]

I didn't Gioogle this part, but I've got a comment.
With the advent of RoHS (lead-free) requirements, I've noticed a lot of manufacturers
are now adding a one or two letter suffix to their part numbers, to designate them as
lead-free. That may not be the issue here, but a trivia comment.
If CocaCola found this part number, with only a single letter changed at the end of the
suffix, it might be the explanation.