There is a package called 100-LQFP that contains it, and you can find it there. It is very easy to carry because of the Tray-shaped packaging. With a 3.3VV power source, you should be able to use it. A AT43320 number belongs to the family of numbers.
AT43320-AC Features
AT43320-AC Applications
There are a lot of Microchip Technology AT43320-AC Controllers Interface ICs applications.