Toshiba IC naming convention

Howdy, I'm looking for some help if possible. I need to replace a Toshiba TC9163N integrated circuit. I've located both TC9163N as well as the TC9163AN variants.

I believe the N stands for the dip package. But I've just spent over an hour trying to figure out what the difference between the N version and the AN versions are. The datasheets don't mention what the "A" stands for.

Can I replace the N version with the AN version?

Any help would be much appreciated!

Thank you
 
I should also add that I think the "A" might stand for the ambient operating temperature but I haven't been able to find any reference to that so I figured it was better to be safe than sorry and ask.

Thanks in advance for any help!

Steve