Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

bipolar (bjt) transistor families for audio power output stages
bipolar (bjt) transistor families for audio power output stages
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd December 2009, 11:19 PM   #211
stinius is offline stinius
Account disabled at member's request
 
Join Date: Oct 2008
Quote:
Originally Posted by Bob Cordell View Post
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.
Interesting, maybe Roadbagger has some more info?

BTW: I tried to order some samples from Linear Systems
  Reply With Quote
Old 23rd December 2009, 11:22 PM   #212
blueskynis is offline blueskynis  Serbia
diyAudio Member
 
blueskynis's Avatar
 
Join Date: Aug 2007
Location: Niš
bipolar (bjt) transistor families for audio power output stages
Quote:
Originally Posted by wahab View Post
double click on the item as soon as ujnzip, window automaticaly open it with its image displayer..
I still can't open the files. Can you use some more accessible image format?
__________________
Windows-free with Linux
  Reply With Quote
Old 23rd December 2009, 11:29 PM   #213
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by blueskynis View Post
I still can't open the files. Can you use some more accessible image format?
i m sorry, i tried, but the converted image appear black, with no reference
of the components..
i dont understand, as the emf format is a windows one that date back to
windows95...it s simply opened with windows telecopy image displayer which is
native on every windows, since w95...
  Reply With Quote
Old 23rd December 2009, 11:34 PM   #214
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by syn08 View Post

Otherwise, I don't know where the posted curves are, therefore I can't really get into such a discussion.
you only read or look at your own posts? in the same thread?..
  Reply With Quote
Old 23rd December 2009, 11:49 PM   #215
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by syn08 View Post
No. A rigurous definition of Fc is "the frequency at which the current through the imaginary and real part of the input impedance are equal".
.
you dont stick to the issue...
we are talking about absolute values in actual devices..
if you prefer, let s say that the frequency at which real and imaginary parts
are equal are (!) higher in the toshiba devices than in the onsemi s, according
to simulations made using models delivered by the respective manufacturers...

does this kind of formulation suits you?...........
  Reply With Quote
Old 23rd December 2009, 11:55 PM   #216
Bob Cordell is offline Bob Cordell  United States
diyAudio Member
 
Join Date: Sep 2006
Quote:
Originally Posted by homemodder View Post
Whoever does these comparisons please use the latest japanese versions and not 30 year old parts, the new parts for audio outputs by toshiba is 2sa2121 and 2sc5949. These have according to datasheet about the same SOA of the onsemi and are faster than the older parts they replace with much lower the capacitances of the onsemi.
Some comparisons with sankens like 2sa1303 and compl would also be welcome.

Bob, these are some of the more modern japanese transistors you asked about. Other outputs Ive tried is allegro sytems 2sc6011 and compl which perform very well too. From what i understand these are made in the US using sanken process technology.
I think you need to look at the datasheets. The 2SC5949 is a bit of a dog compared to the OnSemi MJL. Its ft is down to 9 MHz at only 4A. At least they show an ft vs. Ic curve. Cob is about the same as the MJL's 260 pF. SOA of the 2SC5949 is only 800 mA at 100V, no better than the MJL. I do not understand how you can assert that this is a better transistor than the MJL based on the datasheet.

I didn't look hard at it, but its beta vs. Ic linearity also looks a bit inferior to the MJL.

Toshiba's 30 year old transistors looked better.

Cheers,
Bob
  Reply With Quote
Old 23rd December 2009, 11:59 PM   #217
Bob Cordell is offline Bob Cordell  United States
diyAudio Member
 
Join Date: Sep 2006
Quote:
Originally Posted by wahab View Post
sorry, bob, i didn t mention the actual testbed...
the ac source is not at fixed frequency...
there a sweep in the programed frequency range, and the soft calculate
the frequency response in the boundaries you choose...


regards
Hi Wahab,

I don't think that answers the question. I know you were sweeping the frequency. Where did you get the idea that the circuit is appropriate for measuring ft? Do you have a reference? Your circuit does not appear to measure AC beta vs. frequency, so I do not believe it is useful for evaluating ft.

Cheers,
Bob
  Reply With Quote
Old 24th December 2009, 12:26 AM   #218
syn08 is offline syn08  Canada
Account disabled at member's request
 
Join Date: Aug 2005
Location: Toronto
Quote:
Originally Posted by wahab View Post
you dont stick to the issue...
we are talking about absolute values in actual devices..
if you prefer, let s say that the frequency at which real and imaginary parts
are equal are (!) higher in the toshiba devices than in the onsemi s, according
to simulations made using models delivered by the respective manufacturers...

does this kind of formulation suits you?...........
No. First, you are comparing simulation models not actual devices, some models are notoriously bad or simply do not have provisions for the Beta(f) dependency. Secondly, you need to explain how you simulated those dependencies.
  Reply With Quote
Old 24th December 2009, 12:39 AM   #219
homemodder is offline homemodder  Portugal
Account disabled at member's request
 
Join Date: May 2006
Quote:
Originally Posted by stinius View Post
The devices you mention here should be compared to the OnSemi NJW (TO-3P) devices and not the MJL (TO-264) devices.
Why in the world would you want to compare to a transistor with a higher SOA package, the toshibas are TO264. For TO3p youll have to look at the sanken range and here youll see even a larger advantage for the japanese devices.


Bob nowhere does onsemi accurately state what the capacitance is, so one wont know for sure but ill only believe it if I test it myself and see it.
  Reply With Quote
Old 24th December 2009, 01:41 AM   #220
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by syn08 View Post
No. First, you are comparing simulation models not actual devices, some models are notoriously bad or simply do not have provisions for the Beta(f) dependency. Secondly, you need to explain how you simulated those dependencies.
so you trust onsemi s datasheets, but not the models they publicly
deliver?..seems bad faith to me..

what is measured by the circuit is the ac voltage gain with a constant
transconductance..
if you prefer, fixed transconductance and variable frequency...

the datasheets show variable transconductance and fixed freaquency,
exactly the contrary....

this is misleading, as the current gain frequency product become
less and less relevant with increasing frequency...
The point is that MJL3281 and 2SC5200 have the same Ft on the datasheets
(you trust datasheets, you said) at 30mhz typical for toshiba, and minimum for on semi..
2SA1302 , the antedeluvian device is credited a meager 10 mhz , but as minimum guaranted..

now, in common emmiter mode, with constant current AC source and low
impedance load on the collector, in the aim to reduce to very little
the influence of the parasistic capacitors, i.e , Cbe and Cbc , the toshiba devices show better bandwith performances , which
tell that beta(f) deacrease sooner on the onsemi s device..

have you an explanation other than the easy one that is to blame the
models wich i said it ad nauseam are those of the manufacturers...
  Reply With Quote

Reply


bipolar (bjt) transistor families for audio power output stagesHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Output transistor power dissipation. nigelwright7557 Solid State 11 26th May 2008 01:55 PM
Power horizontal deflection transistors work fine in output stages ? aldovan Solid State 7 31st August 2007 01:31 PM
sziklai-darlington diamond buffer (SDDB) for power output stages mtlin12 Solid State 5 1st April 2005 06:55 AM
power transistor output capacitance hienrich Solid State 3 26th December 2004 07:18 AM


New To Site? Need Help?

All times are GMT. The time now is 08:36 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki