From time to time on these fora the subject of transistor "fakes" keep appearing. In this case, I am specifically looking at various sources for IRF and IRFP 240s and 9240s, but there is also a more general side to my question.
As it used to be also during the valve era, there will always be an "original" manufacturer of a specific transistor type. If this part gets widely used, the part will very often end up being second sourced by other manufacturers, on a licence, often with the original die films and chemistry, rather like a cooking recipee.
In my specific case, the two sources likely at hand is IR, and Fairchild. On scrutinizing the spec sheets of the two, there are minute differences in specs, but so small that in my opinion they fall under the case of normal production spread.
I do not question the fact that there might be manufacturers that do not adhere to the original spec's as closely as we wish, nor that there are situations of unlicenced copying going on also in the semiconductor industry.
I have myself seen on several occations where particularly "general substitution" parts does not work, but sometimes even commercial productions stretch the parts parameters beyond reason. An example in this cathegory could be the different hFE groups of bipolars.
Along with general comments along these lines, I would very much appreciate your comments on my specific issue, - do you really believe that Fairchilds IRFPs are inferior to the original IR..??
BTW---I do not dispute the different tempco of IRFs vs IRFPs.....
As it used to be also during the valve era, there will always be an "original" manufacturer of a specific transistor type. If this part gets widely used, the part will very often end up being second sourced by other manufacturers, on a licence, often with the original die films and chemistry, rather like a cooking recipee.
In my specific case, the two sources likely at hand is IR, and Fairchild. On scrutinizing the spec sheets of the two, there are minute differences in specs, but so small that in my opinion they fall under the case of normal production spread.
I do not question the fact that there might be manufacturers that do not adhere to the original spec's as closely as we wish, nor that there are situations of unlicenced copying going on also in the semiconductor industry.
I have myself seen on several occations where particularly "general substitution" parts does not work, but sometimes even commercial productions stretch the parts parameters beyond reason. An example in this cathegory could be the different hFE groups of bipolars.
Along with general comments along these lines, I would very much appreciate your comments on my specific issue, - do you really believe that Fairchilds IRFPs are inferior to the original IR..??
BTW---I do not dispute the different tempco of IRFs vs IRFPs.....
"Second source" doesn't exist in real world. Check for instance BC55x and LM324 from different sources. Can differ a lot!
You should allways read the datasheets from each manufacturer.
Second source means: Parts are almost alike but usually differs in one respect, the one which makes your design to get into trouble!
You should allways read the datasheets from each manufacturer.
Second source means: Parts are almost alike but usually differs in one respect, the one which makes your design to get into trouble!
if you're in the government
somethings you want to second source -- a lot of the Unitrode controllers are licensed out to other manufacturers, International Rectifier holds many of the key MOSFET patents and licenses the product out, AMD wouldn't be around except for a licensing agreement with Intel from the 1980's.
When I sell stuff on my website (like the lateral MOSFETs or the abovementioned IRF devices) I put a picture of the original manufacturer's packaging --
somethings you want to second source -- a lot of the Unitrode controllers are licensed out to other manufacturers, International Rectifier holds many of the key MOSFET patents and licenses the product out, AMD wouldn't be around except for a licensing agreement with Intel from the 1980's.
When I sell stuff on my website (like the lateral MOSFETs or the abovementioned IRF devices) I put a picture of the original manufacturer's packaging --
Attachments
IRFP240
INTERNATIONAL RECTIFIER 25 TUBE
25+ :1.125
50+ :1.013
125+ :0.862
I only buy genuine IRF parts in sealed packaging from an IRF authorized distributor. One tube is only $28.
Why would you want to do anything else?
If I was driving a solenoid and used 10,000 a month I might be tempted to save $0.02 a part; but even then, that's only $200, and it might not be worth it in the long run.
INTERNATIONAL RECTIFIER 25 TUBE
25+ :1.125
50+ :1.013
125+ :0.862
I only buy genuine IRF parts in sealed packaging from an IRF authorized distributor. One tube is only $28.
Why would you want to do anything else?
If I was driving a solenoid and used 10,000 a month I might be tempted to save $0.02 a part; but even then, that's only $200, and it might not be worth it in the long run.
Thank you all, and NP in particular....
The reason for my question, is that on an international basis, different manufacturers have a rather various form of representation and price policies, as have also been pointed out by especially asian members of these fora.
Also, the representative agents change quickly these days, and many have fairly large minimum orders, even for registered companies, not to mention DIYers.
Luckily, I do work in the electronics field, and so have my ways around....
The reason for my question, is that on an international basis, different manufacturers have a rather various form of representation and price policies, as have also been pointed out by especially asian members of these fora.
Also, the representative agents change quickly these days, and many have fairly large minimum orders, even for registered companies, not to mention DIYers.
Luckily, I do work in the electronics field, and so have my ways around....
Sometimes you have to buy an entire reel (small signal transistors for instance) if you want to pay pennies per part --AuroraB said:Also, the representative agents change quickly these days, and many have fairly large minimum orders, even for registered companies, not to mention DIYers.
Luckily, I do work in the electronics field, and so have my ways around....
Data sheets for 2sk1058 2sj162
for some reason the datasheets for the above seem to be more difficult to find from the original website. i put them up on my website: http://www.tech-diy.com/2sk1058.pdf and http://www.tech-diy.com/2sj162.pdf
for some reason the datasheets for the above seem to be more difficult to find from the original website. i put them up on my website: http://www.tech-diy.com/2sk1058.pdf and http://www.tech-diy.com/2sj162.pdf
peranders said:
I sold semiconductors for a manufacurer once. (Strange for a valve/tube guy eh?):
Second source can also mean the identical part produced by a different manufacurer with supplied duplicate masks. This is done to please the buyers who otherwise would be concerned about batch failures, catastrophe, and industrial action.
The differing spec's of some of these can be explained by alternative measuring and reporting methods.
In those days counterfeit devices were unknown. What surprises me is that any manufacturer could find profit in it. It seems much more likely to me, that the devices are genuine, but re-marked from a lesser(cheaper) type, or stolen failed batch by small counterfeiters.
Cheers,
article in Spanish on counterfeits
the link was posted to rec.audio.tech
http://transfal.tripod.com/
the link was posted to rec.audio.tech
http://transfal.tripod.com/
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