Depends on whether you really need a JFET or simply a normally-on device. If the latter, and if N channels will suffice, you could look at static-induction transistors or depletion-mode MOSFETs.
Or if you really need JFETs, don't mind a bit of extra complexity, or need both P's and N's, how about using JFETs and maintaining a constant, safe VDS across them by adding bootstrapped cascodes?
regards, jonathan carr
Or if you really need JFETs, don't mind a bit of extra complexity, or need both P's and N's, how about using JFETs and maintaining a constant, safe VDS across them by adding bootstrapped cascodes?
regards, jonathan carr
This is being used in an application where they will be used to switch a bi-directional AC signal on or off(max 140v @ 500uA). JFETs are nice for this purpose!
The application invloves a large array of piezo actuators that need to be indivually charged and discharged. We want to have one Driver and a row/column switch matrix to select the piezo actuator. Essentially what we have is a large matrix of capacitors. We cant use MOSFETs. The body diode in a MOS FET causes problems with isolation between elements. There is an array of 256 elements. the array has to be scanned at a 6hz rate (about 650uS per element). Switch has to be fast.
The application invloves a large array of piezo actuators that need to be indivually charged and discharged. We want to have one Driver and a row/column switch matrix to select the piezo actuator. Essentially what we have is a large matrix of capacitors. We cant use MOSFETs. The body diode in a MOS FET causes problems with isolation between elements. There is an array of 256 elements. the array has to be scanned at a 6hz rate (about 650uS per element). Switch has to be fast.
Tokin's static-induction transistors may possibly do the job. AFAIR, these are all N-ch depletion mode (normally on) devices, so I hope that is OK with you.
http://tokin.intercraft.co.jp/pdf/sit000001.pdf
Warning. Text is in Japanese.
Incidentally, some of these devices would be interesting to use in an audio power amp, I reckon. For instance, the 2SK181 has a drain voltage of 800V, a max drain current of 20A, and a power dissipation of 300W. OTOH, Gm is 10S, and the Cis is 2500pF, so the driver and bias circuitry may require some thought...
hth, jonathan carr
http://tokin.intercraft.co.jp/pdf/sit000001.pdf
Warning. Text is in Japanese.
Incidentally, some of these devices would be interesting to use in an audio power amp, I reckon. For instance, the 2SK181 has a drain voltage of 800V, a max drain current of 20A, and a power dissipation of 300W. OTOH, Gm is 10S, and the Cis is 2500pF, so the driver and bias circuitry may require some thought...
hth, jonathan carr
Hi! Perhaps I may have downloaded that data sheet originally, but I have been through multiple computer changes since 2002, and I only have a limited number of Tokin SIT datasheets (2SK180~2SK183, TC-20/TC-30, THF51, TKS45F323, and an overall leaflet).
If that device that you are interested in is none of the above, but you know its name, you could search for that, if not I would simply perform a web search for "Tokin SIT pdf".
SITamp
Otherwise, perhaps you could try sending a PM to Nelson Pass, asking him what he keeps in the way of Tokin SIT datasheets.
kind regards, jonathan
If that device that you are interested in is none of the above, but you know its name, you could search for that, if not I would simply perform a web search for "Tokin SIT pdf".
SITamp
Otherwise, perhaps you could try sending a PM to Nelson Pass, asking him what he keeps in the way of Tokin SIT datasheets.
kind regards, jonathan
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Thank you for the response!!
I was interested in that document because it's referenced here:
SIT Power Amplifier
That particular file name has exactly 3 hits on Google - that page, its copy on some Russian web, and this thread.
I have quite a few different Tokin docs, and I also did try some more generic searches, but found nothing that would match the file size they specifically mention there (4,862kB).
Oh well, I was just curious...
I was interested in that document because it's referenced here:
SIT Power Amplifier
That particular file name has exactly 3 hits on Google - that page, its copy on some Russian web, and this thread.
I have quite a few different Tokin docs, and I also did try some more generic searches, but found nothing that would match the file size they specifically mention there (4,862kB).
Oh well, I was just curious...
InterFet in Dallas has a couple of parts with 300V breakdown. Their website isn't working for me, so maybe you should call.
Website: InterFET - The JFET Company
Website: InterFET - The JFET Company
Petoluk,s post and comment --"exactly 3 hits on Google " is of high interest to me as I have zero Google on my Linux PC and have barred many of its network ports .
I do have many small independent search engines with servers based in the EU or elsewhere that don't "phone home " nor subversively "acquire your data " from using their server and with just one of those I have several webpages just punching in --Sit Power Amplifier .
Having said that there is a search engine totally devoted to technical matters , I found it once but haven't looked for it for a long time , I think I bookmarked it and will have a look.
I do have many small independent search engines with servers based in the EU or elsewhere that don't "phone home " nor subversively "acquire your data " from using their server and with just one of those I have several webpages just punching in --Sit Power Amplifier .
Having said that there is a search engine totally devoted to technical matters , I found it once but haven't looked for it for a long time , I think I bookmarked it and will have a look.
Umm, I didn't want to cause so much activity in this ~20-year old thread!
But I was referring to the file name of the document I'm interested in - "sit000001.pdf" - that (enclosed in quotes to get only exact matches) returns just 3 results.
In general, I will use any search engine I can get my hands on because - despite popular belief - not everything is on Google. E.g. I found ample stock of those precious Toshiba parts (genuine AND cheap!) via Yandex.ru that no other search engine knew of.
Does KGB have my data now? Most certainly. Was it worth it? Definitelyeah!
Ookay, we should let this thread go back to sleep now...
But I was referring to the file name of the document I'm interested in - "sit000001.pdf" - that (enclosed in quotes to get only exact matches) returns just 3 results.
In general, I will use any search engine I can get my hands on because - despite popular belief - not everything is on Google. E.g. I found ample stock of those precious Toshiba parts (genuine AND cheap!) via Yandex.ru that no other search engine knew of.
Does KGB have my data now? Most certainly. Was it worth it? Definitelyeah!
Ookay, we should let this thread go back to sleep now...
Reading the top section of Kamijo-san's Evolve amplifier webpage suggests that the linked pdf was a general catalog to introduce Tokin's range of SIT devices that are potentially suitable for audio amplification, rather than a detailed document that went into great detail.
It therefore wouldn't surprise me if the following link is the same document
https://www.tezukuri-amp.org/evo/amp/device/TOKIN_SIT.pdf
Pity that the original Nymeria server that housed Kamijo-san's data seems to have vaporized.
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It therefore wouldn't surprise me if the following link is the same document
https://www.tezukuri-amp.org/evo/amp/device/TOKIN_SIT.pdf
Pity that the original Nymeria server that housed Kamijo-san's data seems to have vaporized.
Device Lists
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