Questions about Transistors with high beta (hfe) up to 3000 without Darl.-Topology - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 11th December 2011, 09:05 AM   #21
diyAudio Member
 
Join Date: Dec 2005
Location: Kuala Lumpur
Nice device at around 100mA. Only 60V (80V for A suffix) so good for +/- 25V rails. The ft curve is at 12V and is likely to drop a lot at lower voltage typical of cascode for higher rail voltages
  Reply With Quote
Old 11th December 2011, 12:08 PM   #22
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by Sch3mat1c View Post
Oh, my mistake it's 2SD1273!
Short form spec from datasheetarchive:
Surprisingly Vce(sat) is tested at only 40 hFE, however it will gladly do the same with much less base current. It starts to look like a FET with Vgs(th) = Vbe, in that you hardly need any current to drive it -- enough that, whatever peak capacity a gate drive source would supply (even logic level), it's more than enough to turn this thing on.
Tim
thank you.
2SD1273/2SD1273A - hFE Rank classification:
Q: hFe = 500 to 1000
P: hFE = 800 to 1500
O: hFE = 1200 to 2500

The outline is TO220F.

http://www.datasheetcatalog.org/data...c/2SD1273A.pdf
http://www.datasheetcatalog.org/data...JD00065BED.pdf

Are there also an TO220 version sourced from the same process in a non isolated outline ??
  Reply With Quote
Old 12th December 2011, 03:12 PM   #23
diyAudio Member
 
Join Date: Sep 2004
Location: virginia
In a 2007 article I can't find, Bob Pease pointed out that as transistor beta increases the transistor mu decreases. As the beta increases the Hre increases (becomes worse) and the early voltage decreases. Mu is the inverse of Hre and the theoretical maximum voltage gain is the early voltage divided by the thermal voltage. High beta isn't all good.
  Reply With Quote
Old 12th December 2011, 05:17 PM   #24
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by rayfutrell View Post
In a 2007 article I can't find, Bob Pease pointed out that as transistor beta increases the transistor mu decreases. As the beta increases the Hre increases (becomes worse) and the early voltage decreases. Mu is the inverse of Hre and the theoretical maximum voltage gain is the early voltage divided by the thermal voltage. High beta isn't all good.
mean you this author?
Bob Pease - Wikipedia, the free encyclopedia
http://www.eeweb.com/spotlight/interview-with-bob-pease

Last edited by tiefbassuebertr; 12th December 2011 at 05:21 PM.
  Reply With Quote
Old 13th December 2011, 03:03 PM   #25
diyAudio Member
 
Join Date: Sep 2004
Location: virginia
Yes, that's him. I think his article was in EDN magazine in late 2006 or early 2007, but I can't find it. If I recall, he said that too much beta would adversly affect the transistor voltage amplification. I emailed him requesting an explanation because I had never heard that before. He explained that the higher the beta, the lower the mu. If you have ever seen a superbeta transistor on a curve tracer, the early voltage is very low.
  Reply With Quote
Old 13th December 2011, 04:00 PM   #26
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by rayfutrell View Post
Yes, that's him. I think his article was in EDN magazine in late 2006 or early 2007, but I can't find it. If I recall, he said that too much beta would adversly affect the transistor voltage amplification. I emailed him requesting an explanation because I had never heard that before. He explained that the higher the beta, the lower the mu. If you have ever seen a superbeta transistor on a curve tracer, the early voltage is very low.
perhaps the article is mentioned in one of the TOC's about
2007 Print Archives | EDN
or
2006 Print Archives | EDN

Unfortunatly only from this year there are to find cover images of this magazine about
2011 Print Archives | EDN

here a photo galerie of the author from this article:
http://www.edn.com/blog/Anablog/4116...to_gallery.php

Last edited by tiefbassuebertr; 13th December 2011 at 04:14 PM.
  Reply With Quote
Old 13th December 2011, 05:33 PM   #27
diyAudio Member
 
Join Date: Sep 2004
Location: virginia
I think the article may be in ED not EDN, but I can't find it.
Author : Bob Pease
  Reply With Quote
Old 13th December 2011, 06:01 PM   #28
diyAudio Member
 
Join Date: Sep 2004
Location: virginia
Found this, but I still can't find the article. It has to be there somewhere.
http://www.electronicdesign.com/arti...lbox18153.aspx

Last edited by rayfutrell; 13th December 2011 at 06:08 PM. Reason: link to article didn't work
  Reply With Quote
Old 13th December 2011, 07:21 PM   #29
diyAudio Member
 
Join Date: Sep 2004
Location: virginia
Finally found it. I looked all afternoon for this.
What's All This V<sub>BE</sub> Stuff, Anyhow? (Part 2)
  Reply With Quote
Old 13th December 2011, 08:09 PM   #30
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by rayfutrell View Post
Finally found it. I looked all afternoon for this.
What's All This V<sub>BE</sub> Stuff, Anyhow? (Part 2)
Thank you very much for your efforts to find this paper.
Part 1 you will find about:
What's All This VBE Stuff, Anyhow?

Best of Bob Pease - overview
The Best of Bob Pease
Book "Analog Circuits" read samples:
Analog circuits - Bonnie Baker - Google Bücher
Attached Images
File Type: gif Fig 1 vbe1.gif (47.1 KB, 114 views)
File Type: gif Fig 2 vbe2.gif (45.9 KB, 114 views)
File Type: gif Fig 3 vbe3.gif (53.9 KB, 113 views)
Attached Files
File Type: pdf Bob Pease Whats All This VBE Stuff Anyhow Part1+2.pdf (54.7 KB, 24 views)

Last edited by tiefbassuebertr; 13th December 2011 at 08:32 PM.
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
measuring hfe / beta gain Parts 10 12th October 2013 01:43 PM
Matching transistors - Measuring hfe TomWaits Solid State 118 3rd March 2007 06:22 PM
Need low power high beta transistors - please drop me a few part numbers... peufeu Solid State 37 3rd November 2006 12:22 AM
Confused over hfe variation in BC559 transistors Beggar Parts 5 29th September 2002 06:13 AM


New To Site? Need Help?

All times are GMT. The time now is 12:25 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2