Hi fangfang,
I checked both sites you recommended as well the others on the list. They all don't have the AV3 available in small qtys.
I literally went down the list of Arrow, Avnet, Digikey, Mouser, Newark (and others) and nobody sells the MF4SAM3 line in any form in less than full reel/6k/25k qtys.
Is there any other arrangement available? We are already active implementers of your Desfire EV2 RFID cards and would be interested in getting the right SAM AV3 integrated into our system.
Jeff