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Old 2nd February 2010, 08:31 PM   #1
ijomojo is offline ijomojo  Austria
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Default semisouth for bosoz?!?

while hunting for better parts for x-ccs-bosoz i found this:

http://www.semisouth.com/products/up...550_rev1.3.pdf

seems to be a newer, lower power version of their jfets

capacitance is about the same as irf610 - but hey, its a jfet

despite the difficulties of getting hands on them - shouldn't one expect some excitement?

regards
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Old 2nd February 2010, 08:36 PM   #2
Magura is offline Magura  Denmark
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Well, one way to get exited about the Semisouth products, is to try to buy some.

High cost, slow service, long lead times, spiced up with an answering machine when you call them.

Such a cocktail at least managed to get me exited


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Old 2nd February 2010, 08:46 PM   #3
ijomojo is offline ijomojo  Austria
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i am sure you know what you are talking about

there is a distributor in italy claiming to have the new jfets availible from beginning of 2010... didnt ask for prices or minimum orders but these critters looked so juicy to me, i had to share my hornyness
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Old 3rd February 2010, 09:21 PM   #4
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The new part look fascinating!
The Ciss of the new 1700V part looks much lower than old 1200V part at VDS of our interest.
Trying too read Ciss at roughly VDS=10V (a little hard due to scale of graph) shows that the new part is about 200pF, while even the smallest old part SJEP120R125 shows like 700pF.
Another thing is the ID vs VGS curve, the new part very linear from ID=3A onwards, while the old part SJEP120R125 needs 10A to be so.
The only disadvantage is RthJC thermal resistance, old part 1.1C/W while new part 2.6C/W. But the ratio is still smaller than 10A to 3A.
The larger thermal resistance with smaller Ciss seems to suggest that this part uses less wafer area, so hope that it is cheaper.
Anyone making a GB?
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Old 3rd February 2010, 09:34 PM   #5
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Quote:
Originally Posted by ijomojo View Post
while hunting for better parts for x-ccs-bosoz i found this:

http://www.semisouth.com/products/up...550_rev1.3.pdf

seems to be a newer, lower power version of their jfets

capacitance is about the same as irf610 - but hey, its a jfet

despite the difficulties of getting hands on them - shouldn't one expect some excitement?

regards
BTW, thanks for the info!
I wrote to them asking about the price.
Hopefully they will entertain our small need and give a reasonable price.
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Old 4th February 2010, 04:51 AM   #6
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It looks like a nice part. I'll have to get some.

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Old 4th February 2010, 06:26 AM   #7
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Quote:
Originally Posted by Nelson Pass View Post
It looks like a nice part. I'll have to get some.

If you are buying, can I piggyback on you and get a few hundreds together?

Looking at the datasheet, do you think the gate current comes in a little too early? (at 175c, there is noticeable gate current from VGS=2.0V, which correlate to ID=2.2A@125C or 1.8A@175C only) If I did not get it wrongly, if we want this part to have peak ID>3A per device or so, we will need to supply IG in the range of tens of mA. Since we are likely to parallel a few of these to get sufficient power dissipation and transconductance, the front end will need to be capable of delivering 100mA or so. If we keep maximum ID per device below 1.5A, this gate current will be gone though.

Last edited by zhoufang; 4th February 2010 at 06:43 AM.
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Old 9th February 2010, 09:43 PM   #8
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I have ordered some (few hundred) SJEP170R550 from semisouth, other than just the old SJEP120R100.
The leadtime is quoted to be 2-3 weeks.

Quote:
Originally Posted by Nelson Pass View Post
It looks like a nice part. I'll have to get some.

Nelson,
In case that Semisouth charge $60/piece instead of giving free samples to ex-customers, may I have the honor to contribute a few pieces of these to you as an appreciation of your generosity?

Quote:
Originally Posted by ijomojo View Post
despite the difficulties of getting hands on them - shouldn't one expect some excitement?
I think so too. Even Papa get interested.

Last edited by zhoufang; 9th February 2010 at 09:47 PM.
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Old 9th February 2010, 09:48 PM   #9
Magura is offline Magura  Denmark
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The 2 to 3 week lead time, is highly optimistic

It's been more than 3 weeks since I placed an order, and I sure have not seen any sign of them yet.

It though varies how long lead time they quote.....One could suspect they throw a dice when asked, and convert the number of eyes to weeks

Anyhow, could be fun to see what they can do soon.

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Old 9th February 2010, 09:58 PM   #10
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Only SJEP170R550 is quoted for 2-3 week, and only for up to 1k quantity.
For SJEP120R100, or for SJEP170R550 at >1k quantity, lead time quote to be 10+ weeks.

So I think what they quote might actually makes sense.

Last edited by zhoufang; 9th February 2010 at 10:01 PM.
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