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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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30th Jul 2022, 7:12 am | #1 |
Pentode
Join Date: Dec 2019
Location: Egersund, Norway
Posts: 208
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Mosfet NTMFS4899NF
Hello, anybody who know where to buy 8 pieses of the above mosfet?
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30th Jul 2022, 11:46 am | #2 |
Octode
Join Date: Jul 2004
Location: Evesham, Worcestershire, UK.
Posts: 1,422
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Re: Mosfet NTMFS4899NF
Our old friends aliexpress have them, quality unknown...
Greg.
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31st Jul 2022, 7:55 am | #3 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
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Re: Mosfet NTMFS4899NF
Doesn't look anything special apart from an intergrated schottky 30v 75A would another similar type not do the job?. Always amazes me when little parts like this are rated at such high current.
Andy.
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31st Jul 2022, 4:31 pm | #4 | |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
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Re: Mosfet NTMFS4899NF
Quote:
This very badly caught a company out. Their Chief of Electronics was actually Chief of designing by data sheet and missed this important point and threatened to sue ST over misleading specs because they even ignored the prorotype testing stage before ordering a production size batch. When they did do some testing, the lids came off. The specs were fine, he was clueless that's all. |
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31st Jul 2022, 6:33 pm | #5 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
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Re: Mosfet NTMFS4899NF
Aye, sounds about right Duncan, obviously any parts wattage rating is only as good as how much heat you can get rid of.
I've had a dig around and found some 75N03 fets - https://pdf1.alldatasheet.com/datash...EMI/75N03.html , pulls, but test good if you want them. I think I have about 7. Andy.
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31st Jul 2022, 7:01 pm | #6 |
Moderator
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Location: Fife, Scotland, UK.
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Re: Mosfet NTMFS4899NF
They are listed as obsolete.
It is possible that the same die is available in a different package. It is possible that it went obsolete because it has been superseded by an improved part. These mean that you need to look for a different part number having different specifications which meets or improves on those of the original part. In order to progress, you need to understand the circuit the original device was used in, so that you can judge which specifications are important, and which give you some freedom. As it's a surface mount part, you will need something in the same package as a definite 'must have' requirement. Onsemi would be the logical place to start searching to see if they have a suggested replacement. There is no easy answer which can be given without even knowing the application. There may be some stocks somewhere in the world left at a distributor, but large authorised distributors are required by their accountants to minimise inventory of parts without mass turnover, so they dump them on the market. This secondary market is where the chip fakers operate. You don't know whether you're dealing with someone who has real ones, or with a faker ready to write that part number on anything in what looks like the right package. The safest route is to find a current part which will do the job, and which you can still get from an authorised distributor. Additionally, this sort of MOSFET does not usually die quietly, there may be other damage around it. A long answer because of a short wquestion. David
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31st Jul 2022, 8:01 pm | #7 | |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
Posts: 2,532
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Re: Mosfet NTMFS4899NF
Quote:
Without knowing the application it's not possible to know which parameters are important. The nature of the load, whether it's simply on / off or linear, etc etc. Without knowing which parameters are important to match, especially if the device is being operated in the linear (not fully on or off) region. All of the applications I have been involved with have been fairly straightforward loads being simply on off switches for low voltage non-inductive loads, or straightforward brushed DC motors. Sometimes they failed simply open circuit. But other times they failed low resistance D-S. I say low resistance but R of 1 or 2 ohms, which is much higher than the RDSon. So the die got hot. VERY hot. So there was other damage but it was simply by melting. On the other hand although not in my field of experience they are often used for inductive things like SMPSUs, and the intrinsic body diode is important, so nasty EMFs that would be clamped by this aren't when the FET fails. In this type of application, a failure does indeed wreak havoc. So again, it's important to know the application. |
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31st Jul 2022, 8:10 pm | #8 |
Pentode
Join Date: Feb 2018
Location: Nottingham, Nottinghamshire, UK.
Posts: 229
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Re: Mosfet NTMFS4899NF
You could try alltransistors.com to try and find a suitable equivalent.
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2nd Aug 2022, 8:26 pm | #9 |
Pentode
Join Date: Dec 2019
Location: Egersund, Norway
Posts: 208
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Re: Mosfet NTMFS4899NF
Ok fine! Thanks to all answers§
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