Tom E, thanks for those pictures. There are a few differences compared to suspected fake SIR800.
1.The big dot on fake SIR800 is printed, I use a big magnifier and confirm that. While your pictures shows it should be engraved.
2.The big dot position on fake SIR800 is higher from the bottom edge.
It could be the older 800's had the big dot because mine shown above date back quite a while. Even in the last 2 years, if I used them, it was to deplete old inventory. I haven't bought SIR800DP's in years because they were first obsoleted by the 404 then the A20, plus the Infineon.
Yes, I can see this picture. Is there supposed to be a difference between the left one and the right one? They look the same to me.
Some of Tom E’s pictures show the molded dot, but not all. His pic below shows a laser etched dot. I think the manufacturers vary how they label the chips. Vishay may also have more than one factory making the chips with slight differences in the labeling or one factory might do a molded dot and one a laser dot, etc… It is all quite complex.
There may not be a way to tell a real from a fake unless it’s through electrical measurements. You could have a real manufacturer crank out cheaply made, untested chips and put real, legit looking markings on them. Most will work properly so long as you don’t push it too close to it’s rated limits (the real chips rated limits). Some might have some “leakage” when off.
Here is your original picture of the leaky FET.
If I compare it to your picture of two chips I can see that the laser etched dot is quite a bit higher than the laser etched dot in Tom E’s picture. Is that the point you are trying to make?
I don’t know if that’s proof of a fake or just a slight difference in manufacturing.
I wonder if Vishay keeps a catalog of fake chips or pictures of fakes that they collect over the years? That would be interesting.
Molded dots don’t typically change color. Laser etched dots look more white because it burns into the surface. Same reason the lettering looks white. Who knows, it’s hard to tell by pictures.
They won’t most likely. I tried contacting a few manufactures about fakes in the past all to no avail. They either ignored me completely or gave me a run around and ended up saying I need to talk to the distributor I got it from, which was not possible of course. :person_facepalming:
I spent a few months trying to track down fake attiny85’s at one point, they were super slow to respond and after all that ended up getting no where and just saying to contact the distributor.
Some manufactures might be better to work with but the big ones just don’t seem to care for small orders like ours (small being anything sub ~100k units).
I’ve just sent an email to Vishay. Most likely they won’t reply me with helpful answer though.
On the webpage, Vishay acknowledge there are a lot counterfeits and advise their direct customer to buy from approved distributors only. But I think that doesn’t solve the problem of indirect customers buying a circuits having counterfeit Vishay components.
Having mosfet fever, so I bought 3 mosfet. Checking the resistance between D and S, they are all non measurable, that means they can be considered completely open. I will use the Infineon mosfet to repair another Haikelite TA driver and put it into my old MT03 12000lm.
And the two Haikelite SIR800 are each about 42Mohm and 55Mohm. This is good indicator it is not open enough.
Two SIR800, BSC009NE2LS5ATMA1, SIRA22DP-T1-RE3, NTMFS4H01NT1G
Was too excited and forgot to mention this.
Both Haikelite TA driver having glowing during off with SIR800 mosfet. They are out of box defect, without extended use.
Both are successfully repaired by swapping with Vishay SIRA60 and Infineon BSC009.