Inside every AVR device is a silicon chip that contains the actual electronics that perform all the duties of the microcontroller. That integrated circuit (IC) or chip is then packaged in a plastic body with almost-microscopic wires running from the edges of the chip to the package pins. Several packaging options are available for AVR devices, accommodating a wide range of end-user applications. Mobile devices naturally put a premium on small size and low weight, whereas hobbyists generally prefer larger-format parts that are easier to handle by hand.
The most popular packaging option for the ATmega328 chip is the plastic dual-inline package (PDIP). The last two letters of the complete part number indicate the ...