how many of IRFP240 will match in one batch of 100 units? - diyAudio
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Old 16th February 2013, 05:37 PM   #1
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Default how many of IRFP240 will match in one batch of 100 units?

I am about to order the IRFP240 and 9240 with 610 and 9610 I just wanted to know that in the reel of 100 how many of them are matching in how many sets? just to order the quantity.
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Old 16th February 2013, 08:51 PM   #2
Nisbeth is offline Nisbeth  Denmark
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43

You don't really know that until you get them and start measuring, do you?

/U.
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Old 17th February 2013, 02:57 PM   #3
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How tightly are you matching them, and what is the group size?

For .1v Vgs and pairs, it will be nearly all of them.

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Old 17th February 2013, 03:58 PM   #4
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I bought 50 to get four groups of 6 for an Aleph 4 build.
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Old 17th February 2013, 04:10 PM   #5
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it would be a set of 7 but tolerances... I believe Nelson sir you should tell us how good it has to be how many millivolts
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Old 17th February 2013, 04:11 PM   #6
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original IRF and Vishay both are same or different?
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Old 17th February 2013, 04:30 PM   #7
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Are you after 7 matches ? Seems like an odd number.

In the Pass amps only the MOSFETs in one leg need to be matched, not one leg to another.

Unless you are building an Aleph X which is a different kettle of fish.

Last edited by KatieandDad; 17th February 2013 at 04:33 PM.
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Old 17th February 2013, 04:56 PM   #8
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I have never found the need to match 240/9240's
The source resistor should help balance things.
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Old 17th February 2013, 11:02 PM   #9
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It is rare that anyone bothers to try to match P to N's. In an output
stage the big thing is to get DC current sharing so that no one device
hogs the current.

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Old 17th February 2013, 11:07 PM   #10
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I just went through this exercise with just the 240's for an Aleph X build. I was shooting for quads within 0.010V of each other or better and was able to get matches for about 80% of them. There were a few that were pretty far off for whatever reason (edge of the die?) and a few that were grouped tightly for 3 or a pair, but not four.
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