The 2SC3601E are ultra expensive ...That's not surprising - Rochester Electronics also has 2SA1407E and 2SC3601E....
... and they don't even answer business emails ...KEC Semiconductor manufacturing some famous old device, such as 2SC3423/2SA1360 (KTC3423/KTA1360), but I didn't found any distributor for them
...i
Here's what I'm seeing on the KSA1220A. Backordered till September at Mouser ... and I placed the order in December 2018. Oh Geez.
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I bought 60 in 12/2017, hope more become available.
KSA1220 Price & Stock | DigiPart
trust any of them?
I go to Rochester, they want you to buy all 918 that are in stock = stupid
trust any of them?
I go to Rochester, they want you to buy all 918 that are in stock = stupid
Quasi sat to consider: https://www.diyaudio.com/forums/sol...i-saturation-measured-data-7.html#post5774185
KSC2690A did very well
KSC2690A did very well
I find the ex-Sanyo stuff has been relatively consistent in batches.How well do these compare with the KSC/KSA variety?
Consistent in gain etc?
I'm looking for a good SMD equivalent..
S
As for SOA, yeah the dies in the 160V devices are small. It is pretty much a trade off between Cob and SOA. You can get devices with more SOA like the 2SB1275/D1918 but they are comparatively heavyweight, much like TTA(C)004.
I use the 100V devices in CFP configuration, only with 37V rails. 2SA2205 and C6099 which are NRND in those packages, or 2SB1215/D1815. However in a CFP the value of low as possible Cob is important and the driver idle current is a lot lower than in EF.
Nexperia also do 100V devices as PHPT61002*, but I have never tried them. It also comes in NPN+NPN PNP+PNP and NPN+PNP copack varieties. I mused about trying them as a bias coupling device but never bothered. However with these you'd have to do your own tests to check where their SB limits will be - I'm not sure if their LFPAK56 package's copper sandwich construction practically inhibits SB, or if they just don't bother in their datasheet because they're not expecting people to use it where SB is a problem.
When designing around SMD devices for this, it's pertinent to consider the 100ms pulse rating rather than just looking at DC. Whilst you do need to make sure the dissipation is sufficient, because the manufacturer ratings are often on relatively small naturally cooled lands you do gain a lot by differentiating. On something like a TO-252 if the device were actually plotted using Tc 25 the curves look very different, so there is a lot of scope for increased cooling over the Ta 25 lines.
For those that are not "high rollers", can you say group buy?
mlloyd1
Please check PM.
Patrick
I'm trying to buy these:
KSC3503 only D beta grade is available
KSA1381 E grade is available
Anyone found a source for both type in E's?
This has been an ongoing issue for years. In the sx-Amp You had to match them and the guys were already struggling in 2013 with this issue.
On the nx- amp and later designs, I use beta enhancers so the hFE deltas between the complements are less exposed.
I think the biggest issue we will face in the coming years will be the lack of decent complementary VAS devices - high Vce, low Cob, flat hFE vs Ic etc etc.
I don’t see anyway out of this other than to use a cascode since there are plenty of high voltage bipolars around and feed it with a beta enhanced low voltage stage.
Another challenge awaits us . . .
On the nx- amp and later designs, I use beta enhancers so the hFE deltas between the complements are less exposed.
Hi, would you please circle the "beta enhancers" in green, on the attached nx- amp schematic? Thanks very much.
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Attachments
How about UTC, UNISONIC TECHNOLOGIES CO
Apparently all I could ever need lol
http://www.unisonic.com.tw/datasheet/2SB649_A.pdf
http://www.unisonic.com.tw/datasheet/2SD669_A.pdf
Apparently all I could ever need lol
http://www.unisonic.com.tw/datasheet/2SB649_A.pdf
http://www.unisonic.com.tw/datasheet/2SD669_A.pdf
Has anyone considered nte2633/nte2634 (a bit low voltage) as VAS and nte373/nte374 as predrivers?
https://www.nteinc.com/specs/300to399/pdf/nte373.pdf
https://www.nteinc.com/specs/2600to2699/pdf/nte2633.pdf
https://www.nteinc.com/specs/300to399/pdf/nte373.pdf
https://www.nteinc.com/specs/2600to2699/pdf/nte2633.pdf
Anybody had sim problems with the models for the above? When I sim with 3503/1381 I get good distortion results. When I sim with the models below, its about 5x worse.
The static ciurves look much worse on this part than for the 3503/1381 so I would think these have more distortion in a circuit - which is what you've found.
Good news: they're in stock & on the shelf, today. Buy a few tubes now when you can get them easily.
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I wrote this on another thread, I'm not in the business but these parts coming back seem to support the claim:
I was told, probably 30 years ago, that semi companies "set up" the fab line to do
a run of wafers for a given part type. I don't know how many they make but I'd
assume it is based on some minimum and perhaps anticipated large orders. Those
parts go out to distributors and it could be several years before it comes around
again to make that particular part number. Obviously, parts that are discontinued
are not in the lineup for production.
Seems they were a bit late but finally came around to producing them again.
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