It's in a TO-92 package and has three lines of text on the flat side.
43AD
4040A
1Z10.0
I've ordered several small packages of semiconductors lately, but I have no idea what this is. Googling for it hasn't produced anything useful. Is there someplace else I can look. There are no markings on the bag, and everything on the package, except my address is in Chinese.
The LM4040 is a precision two-terminal shunt mode, bandgap voltage reference available in fixed reverse breakdown voltages of 2.048V, 2.500V, 3.000V, 3.3V, 4.096V, and 5.000V.