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Old 23rd January 2003, 12:59 PM   #1
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Default Counterfeit Mosfets

I recently got the opportunity to purchase a quantity of IRFP240's at a very reasonable price ( under half the price of my usual suppliers )
I ordered and received a couple o dozen of these, and then it occurred to me that maybe I'd been stung with fakes.

Has anybody encountered counterfeit IRFP240's ?

These look reasonable, the tabs are nice and flat and the packages look clean and tidy, but the markings don't quite line up with the markings in the IR .pdf datasheet.

The IR logo isn't in the centre ( like it shows on the datasheet) but smaller and offset to the left and is printed within a recessed rectangular window.

Am I being unnecessarily paranoid ? does anyone else have any IRFP240's which look like these ?

I guess the next step is to crack one open to look at the die.
I really hope these are kosher because I'm about to make quite heavy demands of them and I don't want to have to replace 20 in one amp!

cheers

Ray
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Old 23rd January 2003, 01:20 PM   #2
halojoy is offline halojoy  Sweden
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Default Re: Counterfeit Mosfets

Quote:
Originally posted by TheFettler
Has anybody encountered counterfeit IRFP240's ?

These look reasonable, the tabs are nice and flat and the packages look clean and tidy, but the markings don't quite line up with the markings in the IR .pdf datasheet.
Am I being unnecessarily paranoid ? does anyone else have any IRFP240's which look like these ?
I don't want to have to replace 20 in one amp!

cheers
Ray
Well, you are to blaim a little yourself.
Why use the bad MOSFETs in the first place.
When you know they are not as Good as Bipolar.

This is what happens, when you do not use your thinking
in the right way.

So instead of beeing "brainwashed" into using bad MOSFET
you should stick to transistors with real Quality
that is Bipolar High Output Current Devices.

how badly brainwashed can we get ....
noone knows - they are out to get your money .....

Regards
to you Ray - I pity you.... poor fellow
--------------------------------------------

halo - clever enough to understand the datasheets
- prevents him from being fooled into MOSFET troubles
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Old 23rd January 2003, 01:34 PM   #3
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Default Well, you are to blaim a little yourself.

well now , it's clearly time to don the 'ol asbestos suit

of course it's my fault that I chose 'fets . as for your mean slurs against mosfets , well I'm over it It's an old argument that I'm not going to persue here.

suffice to say that the design is an upgrade of an existing design which calls for multiple output devices ....

my last design used 2SC2625's ....erm... because I had some kicking about.


have you seen IRFP240 's like these ? please tell me that I'm just whingeing over nothing 'cos I'd hate to have to go out and buy another 30-odd from another supplier!

Ray
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Old 23rd January 2003, 01:38 PM   #4
halojoy is offline halojoy  Sweden
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Poor friend
you are forced into using them
even worse

I feel real sad for you
and the likes of you

Easily fooled into giving money away, for fakes...
Can it be worse?

halo - likes his TO3 Bipolar devices
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Old 23rd January 2003, 02:17 PM   #5
HDTVman is offline HDTVman  United States
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"halo - likes his TO3 Bipolar devices " A lot of fakes of these around also.

Any time the price is to good to be true, it is to good to be true. If you have FETS from a trusted source you can compair to, I would test the parts in question and compair to known good ones by doing a matching test and see what you get.

You could try contacting the manufacturer and asking them about the part as well. Perhaps by e-mail with a photo of the part. If they are fake they will want to know about it.

As for "halojoy" you are free to press the ignore button if you wish.

Later
Bruce
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Old 23rd January 2003, 02:27 PM   #6
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Default Re: Counterfeit Mosfets

Quote:
Originally posted by TheFettler
The IR logo isn't in the centre ( like it shows on the datasheet) but smaller and offset to the left and is printed within a recessed rectangular window.
Forget those nice looking pictures in the datasheets. Very often (always?) they are drawings not photos. Compare with Burr-Brown for instance.
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Old 23rd January 2003, 02:27 PM   #7
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Bruce , these came from a trusted source , and I think that they are ok , but I can't ignore a nagging doubt in my guts - the consequences of having them fail in service could be very expensive.

I'll order some from a different supplier and compare the two lots.

cheers

Ray

BTW when I tried matching them into sets the range of values was exactly as I would have expected from genuine ones, but thats not really any real evidence is it. I guess pretty much any n-channel fet would give a similer result.
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Old 23rd January 2003, 02:34 PM   #8
UrSv is offline UrSv  Sweden
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how about posting a picture and let the masses be the judge?
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Old 23rd January 2003, 02:39 PM   #9
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Default how about posting a picture and let the masses be the judge?

ok, thats a good idea, I'll take a couple of snaps tonight and post them here. I might even break one open and take a pic of the die too.


cheers,

ray
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Old 23rd January 2003, 02:43 PM   #10
UrSv is offline UrSv  Sweden
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Default Re: how about posting a picture and let the masses be the judge?

Quote:
Originally posted by TheFettler
ok, thats a good idea, I'll take a couple of snaps tonight and post them here. I might even break one open and take a pic of the die too.


cheers,

ray
Sounds like it would help. Can't blame you for wanting the real thing. Everybody knows that "Good FETs die hard" so one cracked open would be good...
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