iPad - Wikipedia

1st generation: Apple A4 2nd generation: Apple A5 3rd generation: Apple A5X 4th generation: Apple A6X 5th generation: Apple A9 6th generation: Apple A10 Air: Apple A7 Air 2: Apple A8X Mini 1st generation: Apple A5 Mini 2 and 3: Apple A7 Mini 4: Apple A8 Pro 12.9-inch 1G and 9.7-inch: Apple A9X Pro 12.9-inch 2G and 10.5-inch: Apple A10X Fusion

Apple A5 - Wikipedia

The Apple A5 is a 32-bit system-on-a-chip designed by Apple Inc. and manufactured by Samsung and is the successor to the Apple A4.The A5 commercially debuted with the release of Apple's iPad 2 tablet, and also powers the iPhone 4S, iPod Touch fifth generation, Apple TV third generation, and the iPad mini.This is consistent with how Apple debuted the A4 chip: first in the original iPad