Texas Instruments N suffix, for BQ2201SN-N

Comparing the Texas Instruments SRAM IC chip BQ2201SN and BQ2201SN-N, what difference does the -N make?

The -N, which is the last digit of the part number, is for the Temperature range.

blank = Commercial (0 to +70°C)
N = Industrial (-40 to +85°C)

Click here for the datasheet, and this information is on page 11.