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Old 19th December 2009, 12:40 AM   #111
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Bob,
Quote:
You know not of what you speak. Have you worked at Moto? BTW, not all transistors designed primarily for the switching market are unsuitable for audio. This same ignorance applies to those who think you cannot make a good audio amplifier out of HEXFET vertical MOSFETs.
Pardon my ignorance, but I cannot see why just make a bad copy if a skill is there.
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Old 19th December 2009, 01:44 AM   #112
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stinius,
maybe you should use what you got now, but next time make sure your specimens are fabricated by Toshiba or Sanken, free from switch-ion implantation and 3055-doping.
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Old 19th December 2009, 02:19 AM   #113
Bigun is offline Bigun  Canada
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Originally Posted by Lumba Ogir View Post
switch-ion implantation and 3055-doping.
what are these things ????
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Old 19th December 2009, 11:15 AM   #114
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Wahab is the only one that nearly got it right......

If some googling is done youll soon find out that the range of onsemi and fairchild output devices are near copies of the japanese 2sa1302. This shouldnt be any new news as it was even clearly stated on some of their datasheets and on their websites. These companies didnt just suddenly start making better output devices from their own technology, its 100 percent japanese technology, and even the equipment used to manufacture them. The US and Japan reached a technology transfer deal as part of a trade equalisation deal some years years ago. Japan would reveal some of their manufacturing and process technology and in exchange the US would allow more goods from Japan.

The deal was made was made because Japan was killing silicon valley with its far superior manufacturing abilities and knowhow so to counter this and running out of options and excuses to give on exactly why they were restricting trade from the east which they were doing so to keep their semiconductor industry and a lot of others from colapse ,the US politians struck this deal and silicon valley was given the technology to be able to manufacture these same goods or die a slow death.

This has given Onsemi and fairchild and a host of other companies a huge jump in manufacturing and process technology, Onsemi and motorola output devices and others were of mediocre performance at best and now they could at least compete, for the japanese they see no problem with it as its technology they were already in the process of diskarting anyway as can be seen from their vastly reduced range of traditional semis.

Didnt anyone ever wonder why suddenly american companies were producing near copies of some of the excellent japanese parts or why new semiconductor manufacturers were suddenly popping up all over silicon valley, manufacturing semiconductors according to japanese processes and technology. Look whats happening in the JFET industry ......., how exactly did the LSK parts come about or interfet.

Read this book, it will help explain some things << U.S.-Japan Strategic Alliances in the Semiconductor Industry: Technology Transfer, Competition, and Public Policy >>
Written out of American point of view but be sure to find some literature on the japanese point of view, interesting stuff. A Better title would have been <<< Japan comes to the rescue of the American semiconductor industry>>

I dont think the american parts are yet up to Japanese standards, I dont think anyone can ever replicate their precise high standards so if a I had to choose between Onsemi and original japanese parts for a first class circuit I think Id stick with the originals.
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Old 19th December 2009, 05:33 PM   #115
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Originally Posted by homemodder View Post
Wahab is the only one that nearly got it right......

If some googling is done youll soon find out that the range of onsemi and fairchild output devices are near copies of the japanese 2sa1302. This shouldnt be any new news as it was even clearly stated on some of their datasheets and on their websites. These companies didnt just suddenly start making better output devices from their own technology, its 100 percent japanese technology, and even the equipment used to manufacture them. The US and Japan reached a technology transfer deal as part of a trade equalisation deal some years years ago. Japan would reveal some of their manufacturing and process technology and in exchange the US would allow more goods from Japan.

The deal was made was made because Japan was killing silicon valley with its far superior manufacturing abilities and knowhow so to counter this and running out of options and excuses to give on exactly why they were restricting trade from the east which they were doing so to keep their semiconductor industry and a lot of others from colapse ,the US politians struck this deal and silicon valley was given the technology to be able to manufacture these same goods or die a slow death.

This has given Onsemi and fairchild and a host of other companies a huge jump in manufacturing and process technology, Onsemi and motorola output devices and others were of mediocre performance at best and now they could at least compete, for the japanese they see no problem with it as its technology they were already in the process of diskarting anyway as can be seen from their vastly reduced range of traditional semis.

Didnt anyone ever wonder why suddenly american companies were producing near copies of some of the excellent japanese parts or why new semiconductor manufacturers were suddenly popping up all over silicon valley, manufacturing semiconductors according to japanese processes and technology. Look whats happening in the JFET industry ......., how exactly did the LSK parts come about or interfet.

Read this book, it will help explain some things << U.S.-Japan Strategic Alliances in the Semiconductor Industry: Technology Transfer, Competition, and Public Policy >>
Written out of American point of view but be sure to find some literature on the japanese point of view, interesting stuff. A Better title would have been <<< Japan comes to the rescue of the American semiconductor industry>>

I dont think the american parts are yet up to Japanese standards, I dont think anyone can ever replicate their precise high standards so if a I had to choose between Onsemi and original japanese parts for a first class circuit I think Id stick with the originals.
Thanks. Interesting story and I'm sure there is some truth to it. However, generalizations can always be dangerous, especially when making claims about the superiority or technology of one country vs another without qualifying it to a business sector. The Japanese are much more driven by consumer electronics than the US, so some of that is reflected in discrete semiconductors for audio. I'm pretty sure they were the first with Ring Emitter Transistors almost 30 years ago, for example. I think they were also first with Lateral MOSFETs. They were definitely NOT the first with the HEXFET-type vertical MOSFET technology.

As far as Moto/On doing their own thing with perforated emitter technology, I'd guess it is just as likely that some Japanese patents ran out.

I believe that the Linear Systems LSK389 is a copy of the famous National NPD5564 that was available beginning in the 1970's.

BTW, beware that just because someone uses some of the same numbers does not mean the transistor is a copy or even has the same specs.

The fully complementary junction-isolated BJT IC process was invented and developed at Bell Laboratories and subsequently adopted by Analog Devices.

The 32 nm process at Intel is at least as advanced as Japanese ULSI processes.

There are numerous other examples that show that it is dangerous to make generalizations.

Cheers,
Bob
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Old 19th December 2009, 05:52 PM   #116
wahab is offline wahab  Algeria
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bob, according to onsemi own specifications, their bjts are inferior to the
japanese ones, even in the devices that are second sourced...
thus MJL1302/3281 are inferior to the 2SA1302/2SC3281 they are supposed
to second source...this is reflected by onsemi s pulished spice models..

here the sims used each manufacturer spice models..
the figure for the MJL21193/21194 is particularly ugly...
the test is done with a forced beta of 20, not a high value..

wahab
Attached Files
File Type: zip EF SWITCHING TIME.zip (18.3 KB, 55 views)
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Old 19th December 2009, 06:33 PM   #117
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Bob its not that there is some truth to it, its the full truth, youre welcome to read the book, it was written by a comitee created by the us goverment after being asked by the semiconductor industry for help to investigate ways to counter the takeover by the japanese manufacturing industry, this not only happened to the semi industry it happened to nearly all other high tech industries.

I dont see anything dangerous about claiming japanese superiority in manufacturing process, it is very well known and studied subject, at varsity during my course we had a subject called industrial relations and it was nearly all devoted to this problem, the only cure being keeping up with advanced circuit design.

No one is claiming they were the first, but that they perfected the known techniques is of no doudt, read the book, even that comitee admits it. The deal also not only involved silicon valley but europe too which was in the same boat, look what happened to european semi manufacturers too.



Patents is exactly what the deal was about, the west was allowed to manufacture according to japanese process technology.

Well after you learned how to do it and youre using the same equipment off course you can do it yourself which is the case with the 90 45 and now 32nm process, but you ever wonder why even these are being manufactured in the east, because of price ???? partially, if you cant beat them buy them out and claim it as yours.

The fairchild range of ksa transistors are 100 percent copies of the japanese devices manufactured in the us according to japanese proceses, the same applies to the newer onsemi output devices that suddenly leaped from being mediocre to pretty good. Changing from package does not make it a new innovation.

Last edited by homemodder; 19th December 2009 at 06:43 PM.
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Old 19th December 2009, 09:53 PM   #118
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Quote:
Originally Posted by homemodder View Post
Read this book, it will help explain some things << U.S.-Japan Strategic Alliances in the Semiconductor Industry: Technology Transfer, Competition, and Public Policy >>
Written out of American point of view but be sure to find some literature on the japanese point of view, interesting stuff. A Better title would have been <<< Japan comes to the rescue of the American semiconductor industry>>
I dont think the american parts are yet up to Japanese standards, I dont think anyone can ever replicate their precise high standards so if a I had to choose between Onsemi and original japanese parts for a first class circuit I think Id stick with the originals.
Thank you for your advice to this book. Here an excerpts (read sample) of this book about "books.nap" and "Google Books":
http://books.nap.edu/openbook.php?re...d=2021&page=67
U. S. Japan Strategic Alliances in ... - Google Books
and delivery sources:
http://www.politicos.co.uk/books/425...ctor-Industry/
http://openlibrary.org/b/OL10357256M...uctor_Industry

Last edited by tiefbassuebertr; 19th December 2009 at 10:02 PM.
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Old 19th December 2009, 11:05 PM   #119
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Originally Posted by wahab View Post
bob, according to onsemi own specifications, their bjts are inferior to the
japanese ones, even in the devices that are second sourced...
thus MJL1302/3281 are inferior to the 2SA1302/2SC3281 they are supposed
to second source...this is reflected by onsemi s pulished spice models..

here the sims used each manufacturer spice models..
the figure for the MJL21193/21194 is particularly ugly...
the test is done with a forced beta of 20, not a high value..

wahab
As a strong proponent of the use of SPICE in power amplifiers, I wish I could tell you that the SPICE models provided by manufacturers are accurate. They usually are not. Just ask Andy_C. Secondly, a simulation of switching time is not appropriate for evaluating the audio performance of a power transistor.

Compare the actual datasheet information for the MJL3281 and the 2SC3281 for those parameters most important for an output stage.

Beta at 100 mA and peak beta are about the same, at about 110.

Beta at 10A (beta droop) and 5V is about 70 for both.

Peak ft for the MJL is about 60 MHz, while that of the 2SC is 30 MHz.

Now for the biggie: ft droop at high current and only 5V;
MJL is 30 MHz at 4A; 2SC is only 8 MHz at 4A.
ft of the 2SC3281 really crashes at high current.

Output capacitance of the MJL is specified at 600 pF, while the 2SC is specified at 270 pF. However, OnSemi specifies the same max Cout for the NPN and PNP. The PNP will usually be larger. Note that the Cout of the 2SA1302 is spec'd at 470 pF, much closer to the OnSemi number.

DC SOA at 100V for the MJL and 2SC is about 0.8A for each.

Looks to me like the MJL is a better part at less than half the price.

Cheers,
Bob
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Old 20th December 2009, 12:08 AM   #120
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Quote:
Originally Posted by Bob Cordell View Post
As a strong proponent of the use of SPICE in power amplifiers, I wish I could tell you that the SPICE models provided by manufacturers are accurate. They usually are not. Just ask Andy_C. Secondly, a simulation of switching time is not appropriate for evaluating the audio performance of a power transistor.

Compare the actual datasheet information for the MJL3281 and the 2SC3281 for those parameters most important for an output stage.

Beta at 100 mA and peak beta are about the same, at about 110.

Beta at 10A (beta droop) and 5V is about 70 for both.

Peak ft for the MJL is about 60 MHz, while that of the 2SC is 30 MHz.

Now for the biggie: ft droop at high current and only 5V;
MJL is 30 MHz at 4A; 2SC is only 8 MHz at 4A.
ft of the 2SC3281 really crashes at high current.

Output capacitance of the MJL is specified at 600 pF, while the 2SC is specified at 270 pF. However, OnSemi specifies the same max Cout for the NPN and PNP. The PNP will usually be larger. Note that the Cout of the 2SA1302 is spec'd at 470 pF, much closer to the OnSemi number.

DC SOA at 100V for the MJL and 2SC is about 0.8A for each.

Looks to me like the MJL is a better part at less than half the price.

Cheers,
Bob
I agree no simulation is going to tell you anything about these parts but one thing is for sure Onsemi datasheets have errors, Bob you have much better equipment than me, compare the capacitances as stated by onsemi, actually the the p cob is much higher as it should be, given the structure, little datasheet errors, please also keep in mind you compairing 30 year old japanese component to a recent onsemi one, and overall one shouldnt forget that the onsemi is a 1302 with a little bit bigger die, so will obviously have better SOA but worse cob. I can think of more modern bigger die japanese transistors which are better if you want to compare apples with apples, here youll see better SOA than ONsemi with half the cob. Also youll notice that japanese datasheets are very very accurate unlike the western datasheets which are very optimistic sometimes, use curvetracer and do some comparisons and youll get interesting results.

Onsemi devices are not bad, they are copies of the japanese with much better quality control than like comparing chinese manufactured copies.

Through the channels I get the japanese devices the onsemi would cost me more than double the price, the US goverment still have heafty own industry protection taxation on goods coming in from japan, through the channels I use they are on equal footing and this way the japanese parts are much cheaper so it all depends on where you live and if your goverment is trying to protect your own industry, on level footing its a very different ball game.

Theres some interesting things written about ,,buy local practices,, still being used in the US.
Through tiefbassuebertrlinks you can get some details about the toshiba motorola onsemi marriage.

Last edited by homemodder; 20th December 2009 at 12:22 AM.
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