A RFID transit pass teardown from Electronupdate:
Here is the die photo: super tiny. I bet they get thousands of dice off of each wafer. Looks like it’s a protocol called MIFARE. Vendor of the chips is NXP. I think it’s their ultra light family
The amazing bit is that a card is printed with conductive ink, a semiconductor added (with a transistor count in the tens of thousands), a vendor-specific ID placed on the outside with another layer of paper, spooled in to giant rolls, vended for a single trip and then thrown away…..
More details at Electronupdate blog.
Check out the video after the break.