Possible fake Toshiba/Sanken transistors?

Alright, I'm working on a couple of new designs and have purchased some transistors from two local suppliers, these are companies, hence not private individuals. These transistors are offered as original Toshiba/Sanken transistors.

I however have my doubts on whether these are original, the fact that they come supplied in a plastic bag, rather than a plastic tube like original Sankens, has gotten me a little worried. The original Sanken's pictured below (STD03P/N) were bought from Profusion in the UK, a certified dealer for Sanken.

2SJ201/2SK1530 supplied in a plastic bag

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Full size image, click to open: http://hardwareanalysis.com/images/articles/large/12207.jpg

Original Sanken STD03P/N supplied in a plastic tube

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Full size image, click to open: http://hardwareanalysis.com/images/articles/large/12206.jpg

And now for the possible fakes, they all are printed Toshiba, all seem to have the proper markings on them, but if you look closer the printing all seems different, as the fonts are not the same, the line width differs etc.

Possible fake Sanken MN2488/MP1620

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Full size image, click to open: http://hardwareanalysis.com/images/articles/large/12203.jpg

Possible fake Toshiba 2SC5200/2SA1943

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Full size image, click to open: http://hardwareanalysis.com/images/articles/large/12204.jpg

Possible fake Toshiba 2SJ201/2SK1530

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Full size image, click to open: http://hardwareanalysis.com/images/articles/large/12204.jpg

Now I've had 2SC5200/2SA1943s before that were not manufactured by Toshiba, they were manufactured by ISC (isc,inchange Semiconductor Company Limited Welcome You) but they were stamped 'ISC' and hence it is clear they are not genuine.

But how about these, what do you guys think? I've bought quite a few of each (25-pcs) and I can send them back if I can prove they're indeed fake.

Looking forward to your replies!

Cheers,

Sander Sassen
Hardware Analysis - Computer hardware news, reviews and forums that provide help and assistance with problems.
 
After having found the datasheets for the Sanken MN2488/MP1620 one thing is immediately apparant, the equivalent circuit as documented in the datasheet shows there's a resistor between B and E pins on both the NPN and PNP transistor, hence a simple check with a DVM should tell us whether these are genuine or not. However there's one catch, is that equivalent circuit meant to illustrate the device in use, or not?

Equivalent circuit MN2488, other transistor is the PNP equivalent

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Measuring the transistors however shows no resistor between pins B and E on either the NPN or the PNP, not even at 10x the value, hence is the datasheet outdated and has the device been changed? Or are these simply fake?

Cheers,

Sander.
 
Ah yes, of course, why didn't I see that on first glance? That actually simplifies things, as with the DVM on diode setting you should only see one PN junction, as the ~70-ohm is less of a voltage drop than the second PN junction. I just verified this and there's indeed just a single diode drop from B to E. So I guess these might afterall be genuine?

Cheers,

Sander.
 
You may simply have gotten devices that because of the limited quantity purchased were bulk packed by the vendor.

Repacking for small quantity orders is a pretty common practice and may also help with shipping expense as it allows the use of a compact square box instead of a long rectangular box.
 
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The only way to be really sure is to sacrifice one and break it open......check out the size of the silicon die. If it is really small then it is a fake.

I don't know the size for 2SJ201/2SK1530 but Rod Elliots site Counterfeit Transistors
will give you a rough guide. you could of course open a good one for comparison but it would be painful to destroy a genuine part. Ouch!!
 
On the 2SJ201/2SK1530 MOSFETs it should be possible to note down capacitances between pins, and compare to someone else's 2SJ201/2SK1530, anybody care to whip out his capacitance tester and a pair of MOSFETs? Here's what I got on mine (averaged on 10 transistors of each type).

Pinout 2SJ201/2SK1530

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2SJ201 MOSFET capacitances

- Csd : 2.08nF
- Cgs : 4.25nF
- Cgd : 4.25nF

2SK1530 MOSFET capacitances

- Csd : 1.54nF
- Cgs : 1.60nF
- Cgd : 1.72nF

Cheers,

Sander.
 
If I repeat the same exercise for the possible fake Toshiba 2SC5200 I arrive at the following values (again averaged over 10 transistors).

2SC5200/2SA1943 pinout

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Possible fake Toshiba 2SC5200 capacitances

- Cbe : 6.23nF
- Cbc : 0.68nF
- Cec : 0.61nF

I also managed to find a few of the ISC branded C5200 transistors I mentioned previously and if measure those in the same way and average their results I find the following values.

ISC C5200 equivalent transistor

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Click for full size image: http://hardwareanalysis.com/images/articles/large/12211.jpg

ISC C5200 capacitances

- Cbe : 6.28nF
- Cbc : 0.71nF
- Cec : 0.60nF

These values are pretty much identical, which would indicate that these have somewhat identical dies? I'm no semiconductor manufacturing process specialist, I'm just an engineer that uses the end product, hence I don't know what conclusions can be drawn from the results?

Cheers,

Sander.
 
Kevin,

They come from two distributors here in Holland that supply retailers and repair shops with spare parts, both electronics as well as mechanics and just about everything in between (from replacement parts for your dishwasher down to semiconductors used in A/V equipment). At this point I prefer not to disclose who they are, as the jury is still out on whether these transistors are genuine or not.

Profusion in the UK provides the genuine article, absolutely no question there, I've bought from them before. Actually I have an order in for some Toshiba 2SC5200/2SA1943 transistors with them already just to ease my mind and have some transistors to compare to (they are more expensive than the ones I bought elsewhere though). Unfortunately they do not stock the Toshiba 2SJ201/2SK1530, nor the Sanken MN2488/MP1620.

Cheers,

Sander.
 
Sander.
I`m not quite certain so maybe I should not make any comment, however my feeling is that these are genuine although I find the shabby appearance disquieting. A smaller die implies smaller capacitances.
Why are you using integrated Darlington devices?
 

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It has always been a mystery to me how a group of people could accumulate the resources necessary to manufacture semiconductors and then choose to sell fakes. This is serious money.
Exactly how difficult is it -- after acquiring the equipment, buildings and personnel -- to make good quality devices. I have a couple of 2sj109bl and 2sk389bl dual jfets that I bought recently and probably will never know for sure if they are genuine. The stenciling on the 109 parts is rather faint and the 389 parts are bright and very legible. And for that matter how far from being good parts could they actually be. Don't some of the fakes test quite well?
Most of the genuine Toshiba and Sanken devices are manufactured in the same region as the fake devices which adds to the confusion.
Sometimes the shipper removes the devices from the rail to fit in a more uniform box.

I never got around to telling you how good a job you did with the ExtemeA amp. Real nice. Tad
 
Those Sanken's (MN2488/MP1620) certainly look authentic, in comparison to the Sanken devices I've culled from vintage receivers. Details, like the way the lead is shaped (unequal radius into the leg) are accurate.
Same for the 2SC5200/1943 - they look genuine.
 
Genuine?

Sander,

I am really sure "the dutch supplier" you bought from is selling different fake items. In the past i bought several fakes from them including fake STK modules. Although i am not sure the items you've bought are fake or not, I would suggest to crack one open.
 
Possible fake Toshiba 2SC5200 capacitances

- Cbe : 6.23nF
- Cbc : 0.68nF
- Cec : 0.61nF

I also managed to find a few of the ISC branded C5200 transistors I mentioned previously and if measure those in the same way and average their results I find the following values.

ISC C5200 equivalent transistor

ISC C5200 capacitances

- Cbe : 6.28nF
- Cbc : 0.71nF
- Cec : 0.60nF

These values are pretty much identical, which would indicate that these have somewhat identical dies? I'm no semiconductor manufacturing process specialist, I'm just an engineer that uses the end product, hence I don't know what conclusions can be drawn from the results?

Cheers,

Sander.

What I'd like to see is test data on the ISC. I've seen some of ISC's clones, and they look like garbage - especially the MT200's which do not have the proper heat spreaders in them. But these are pretty close - the capacitances are right. Maybe they paralleled two dies? Or *gasp* got licensing from Fairchild or ST (who make proper clones of the 5200).
 
Those Sanken's (MN2488/MP1620) certainly look authentic, in comparison to the Sanken devices I've culled from vintage receivers. Details, like the way the lead is shaped (unequal radius into the leg) are accurate.

Same here,They look identical to some I've pulled from a Sony receiver,the leads,the lettering,all of it. Note how the SK logo on the MN2488's has slightly thinner lines,the ones I have here in front of me are the same way.
 
I'm pretty familiar with all the websites dealing with counterfeit transistors, as I've also read through the majority of topics here regarding people having doubts about their transistors being genuine.

However, what most (if not all) of these sites/topics lack in my opinion is a thorough investigation and detailed pictures and measurement data. They basically tell you that 1) fake transistors are real 2) best way to find whether you have a fake is to smash a transistor to bits with a hammer.

I'd like to find a less destructive way of determining whether transistors are genuine or not. Measuring capacitances between pins is a good starting point, as are high resolution scans. If we can build a database of know good, and known false parts we might be able to move beyond the 'hammer' approach.

Cheers,

Sander Sassen
Hardware Analysis - Computer hardware news, reviews and forums that provide help and assistance with problems.