Member Since: October 14, 2008

Country: United States

  • This reminds me of a cool video I saw by the EEV blog guy, Dave Jones where he was blowing up DMMs with a 4000V source which was very entertaining. The Fluke had actual protection in it (an MOV) and didn't get toasted like some of the cheaper ones.

  • There is a working example here:

  • Regarding measurement of the 500V, it was covered in the tutorial but I had to think about it again too. When you are putting your meter in between the tube Vcc and ground (tube case) you are making a voltage divider with the 10 Meg resistor. Normally you don't have to think about the impedance of your meter much since its usually so much higher than anything normally measured.

  • Counterfeit shops are all over, even Taiwan unfortunately. Some use older packaging equipment which is probably used and resold equipment. Others are made with state of the art equipment which indicates that some high end contract shops may have "rogue employees."

  • Just a couple of counterpoints based on experience:
    I was talking about the die being salvaged from scrap. The die are often at least partially tested prior to packaging. Whole wafers may be scrapped due to results of those tests. Normally they are destroyed, but not if they are stolen first. This is not hypothetical.
    Laser markings can be remarked. The top surface is sanded (blacktopped) and then remarked. It is noticeable when you see it though. In this case that doesn't seem to have happened

  • There are many kinds of counterfeit, but this is one kind. They were sold as to sparkfun as Atmel parts and they are not.
    Other counterfeits types include empty packages, marginally failing devices, or devices marked to indicate that they have expensive testing done on them when it has not been done. In all cases fraud is involved.
    It's serious issue and there are confernces on this topic (for example

  • Nice photos of the setup. Unfortunately this incident is not uncommon in the industry with all the counterfeit parts out there. I doubt most developers who get them do failure analysis. Be careful who you buy from.
    Just one nitpick with your letter, the photo is of the die. There is a die identifier AG20 and then probably a date code that shows what lot the wafer came from. Lots of die are cut from the large circular wafer.
    It's likely these got stolen from a low yield lot that was in the scrap bin.

  • To continue... the article SHOULD scare you because it is a scary part of our world today. The funny named Hakkmuddin and her lack of technical knowledge is a red herring and not a major point to discuss, but the fact that these reclaimed and conterfeit parts come from China is not funny either. While these guys make a few bucks off the parts they sell, they drive up the cost of our defense and space programs since we have to work harder to weed out the crappy parts and deal with test failures. It's cheaper than hiring spies to sabotage our factories. Whether it's on purpose or not is hard to prove, but the problem is real and it affects the defense of your nation. And off the soap box.

  • It probably seems funny, but unfortunately you are off the mark with your comments about the article. It is a big deal and it is exactly products like the F15 where this matters most. "Fake" chips have been found in all the categories that you describe. Many points I would make have been made by other posters (tin whiskers, etc). I would add that a mature design for aerospace does easily allow other parts to be substituted so manufacturers end up desperately trying to find older mil-grade (really just highly tested) parts. Due to rigorous design requirements its often more expensive to over pay for an IC than to redesign.

No public wish lists :(