anananh, i got the same problem as you before. Then i mail to the info@ maxim-ic.com to check for my sample request. After a few days, Alice replied, informing me that the samples have been shipped. Then, after another the 2 weeks, the samples finally arrived! (Late... better than never ;) ). Maybe it's because we are registered under the title of "student", that's why they are not interest in ship us any samples.