IGBT's as power stage? - 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 28th January 2001, 01:31 PM   #1
diyAudio Member
 
Join Date: Jan 2001
Location: UK
What are everyones opinions on IGBT's as the power stage in a power amp, also does anyone know where I can find a supplier for the Toshiba IGBTs GT20D101 and GT20D201, and bipolars BC617 and BC560C. Any help would be great.

Chris
  Reply With Quote
Old 28th January 2001, 05:16 PM   #2
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Blog Entries: 1
Send a message via Yahoo to vdi_nenna
I know you can find IGBT's at Digi-Key and you may also find the BC's there too. International Rectifiers (IRF) is the maker of the IGBT's at Digi-Key. I know I've seen the BC's at Mouser Electronics. Both of these comapanies are in the USA though.

[Edited by vdi_nenna on 01-28-2001 at 12:18 PM]
  Reply With Quote
Old 29th January 2001, 11:25 AM   #3
diyAudio Member
 
Join Date: Dec 2000
Location: Önnarp, Söderslätt
Concerning where to buy the IGBT`s in the UK, try through this link : http://www.irf.com/whoto-call/distributors/britain.html
Good luck ;o)
__________________
Regards
Hoffmeyer ;0)
  Reply With Quote
Old 4th February 2001, 07:08 AM   #4
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
Default IGBTs

IGBTs are designed for switching.They have very poor power handling when forward biased in an audio circuit.The problem is their SOA ratings at high voltage.Some types have their wattage de-rating line fold back at only 10 volts.
  Reply With Quote
Old 5th February 2001, 05:31 AM   #5
diyAudio Member
 
Join Date: Feb 2001
Location: Silicon Valley
Send a message via Yahoo to thespeakerguy
Analog devices has an app note using IGBTs as the output drivers for one of their opamps. The circuit is patented by Mark Alexander, assigned to ADI. You may be able to find the note in an older ADI databook or on their website.

The amp uses a FET input opamp, (OP42, slightly better than an LF356 or TL072) as the input buffer to a current feedback amplifier. the supplies of the op42 are generated from the emitter of a transistor. The collector of same transistor feeds into a complementary current mirror. The quiescent current of the opamp is balanced and biases the current mirrors. Any output current from the opamp is mirrored into the current mirrors as an error signal. The high impedance junction of the current mirrors is connected to a typical output buffer, albiet with IGBTs as the final driver. The original circuit was designed and patented with MOSFETs.
  Reply With Quote
Old 25th October 2001, 01:26 PM   #6
diyAudio Member
 
Join Date: Oct 2001
Default Best output device

Sorry, IGBTs are poor candidates for linear applications.
They have inherent advvantages over both BJTs and MOSFETs in high-power switching circuits. Indeed, there are numerous technical problems in using them in the audio amplifiers.

But the last word seems to be the sound quality.

It is true fact: IGBT, SIT, vertical and lateral MOSFETS, all of these devices are inherently inferior in this respect to those old BIPOLAR TRANSISTORS!
  Reply With Quote
Old 26th October 2001, 05:59 PM   #7
sonnya is offline sonnya  Denmark
diyAudio Member
 
sonnya's Avatar
 
Join Date: Oct 2001
Location: Denmark
The IGBT's used in the application note from AD IS MADE FOR AUDIO USE. It is the types mentioned :
GT20D101 and GT20D201 from Toshiba if i recall Farnell should have them.
By the way High Fidelity in denmark did make a project some years ago with the CFB design from AD but with more output devices.
This design has a highend soundQ. if it has a big PS and slightly higher current limit.
I did a design myself with a pair of GT20D101/D201 per channel and they did do thermal runaway. Use them as multiple.

Regards

Sonny
  Reply With Quote
Old 26th October 2001, 06:55 PM   #8
km is offline km
diyAudio Member
 
Join Date: May 2001
Location: dk
Smile toshiba igbts

hi.

we stock the toshiba igbts and they are splendid for audio.

the amplifier you refer to is a bad rebuild of mark alexanders current feedback amplifier.

the original use these igbts and is a very good amplifier indeed , for several reasons the high fidelity project turned into a power oscillator (and an expensive one you could add) , its not recommended!

mail me if you want more info or want to buy some of the igbts.

k madsen - km_cad@yahoo.com
  Reply With Quote
Old 26th October 2001, 07:22 PM   #9
sonnya is offline sonnya  Denmark
diyAudio Member
 
sonnya's Avatar
 
Join Date: Oct 2001
Location: Denmark
I think the problem with the High Fidelity design Was to long wires from the driverstage to the igbt. Afterall it is a 1 MHz design even if you try to lower its bandwith by compensating in the feedback loop (Be carefull with CFB design .. Check some papers from AD about designing with CFB).

My own design is also a CFB but without the opamp.
I don't like the idear in the Alexander design. We always learn that opamp should have a low impedance supply even by 100MHz. That can't be achived by the alexanderdesign.
But the alexander amp works. who cares!?

<8O)

I am on to build a new amp with a lot of currentsources. But it is still CFB design ... i think .. .lets see!?

Regards ... Have fun designing...

Sonny
  Reply With Quote
Old 26th October 2001, 08:11 PM   #10
km is offline km
diyAudio Member
 
Join Date: May 2001
Location: dk
Smile alexander cfb amp

hi.

>I don't like the idear in the Alexander design.>

and??

>But the alexander amp works. who cares!? >

it not only works , its a splendid amplifier and it compares very well to other designs , you could add it has a very fine grained hi freq reproduction , it plays very good midrange and quite acceptable bass.

it has very good transient response and in the same time it has quite low bias current.

i think its a combination of very good specs and very good performance.

make a better one (before you dis the alexander amp)

k madsen - cadaudio.dk



  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
Has somebody used IGBT in power amp boske Solid State 32 30th November 2013 12:23 AM
IGBT amplifiers Bama Slamma Solid State 46 29th September 2010 11:24 AM
Balanced compound-IGBT power amp idea revintage Solid State 10 21st January 2008 04:27 PM
IGBT for Aleph power ben goh Pass Labs 2 19th December 2002 05:28 PM


New To Site? Need Help?

All times are GMT. The time now is 12:40 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