Sigma Delta ICs - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

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 31st October 2007, 11:35 PM   #1
d1983 is offline d1983  Canada
diyAudio Member
 
Join Date: Mar 2007
Default Sigma Delta ICs

I was curious if any of you knew of any Sigma-Delta chips that would have an output of the sigma-delta modulated signal rather than a 2's compliment serial out. Or, am I best off to try and design up my own?
Thanks!
  Reply With Quote
Old 2nd November 2007, 02:23 AM   #2
fdeck is offline fdeck  United States
diyAudio Member
 
Join Date: Feb 2006
Location: Wisconsin
It's not a chip, but Tekko has it here:

Another classd from Tekko Audio Labs

Remove the "power output" stage, and you've got a basic sigma delta.

Remove the flip-flop and it is a self-oscillating Class D.
  Reply With Quote
Old 2nd November 2007, 07:12 AM   #3
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
Designing a sigma-delta loop is not that difficult in theory but practical implementation can be a PITA.

There was once a two-chip delta sigma ADC by Burr-Brown that consisted of the delta-sigma modulator/converter and the decimation filter in two seperate ICs. But the delta-sigma converter was 4 bit - I guess that you are looking for a one-bit solution, don't you ?

Regards

Charles
  Reply With Quote
Old 2nd November 2007, 11:33 AM   #4
d1983 is offline d1983  Canada
diyAudio Member
 
Join Date: Mar 2007
Yeah. A one bit stream is really what I'm looking for.
Thanks for the point to the post though. I thought I'd looked through just about all the posts here.
  Reply With Quote
Old 2nd November 2007, 12:19 PM   #5
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
Since you are a student of engineering you probably have access to the JAES, have you ?

There was an interesting article in Vol 52 March 2004 of the JAES called: "One-Bit audio: An Overview"

This is a good article to give you some basic understanding of DS modulators.

Regards

Charles
  Reply With Quote
Old 2nd November 2007, 12:39 PM   #6
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
And here is a nice paper by Bruno Putzeys showing some interesting design -details/-decisions of a practical implementation of a high quality audio ADC :

http://www.grimmaudio.com/whitepaper...0converter.pdf

Regards

Charles
  Reply With Quote
Old 2nd November 2007, 02:07 PM   #7
d1983 is offline d1983  Canada
diyAudio Member
 
Join Date: Mar 2007
I just re-read my post and realized that it sounded sort of.... abrupt.
I read through that thread and it was amazingly helpful, I haven't noticed it before.
And I am looking for a single bit stream. I've started plugging away in OrCAD to try and design one up.
If anyone has any hints about designing the integrator or choosing components I'd love to hear about them, or even if I could be pointed towards another good thread or site that'd be great!
Thanks everyone for your help.
  Reply With Quote
Old 2nd November 2007, 02:16 PM   #8
diyAudio Member
 
Join Date: May 2002
Location: Switzerland
What I could offer you is a simulation model for a DS amp with fourth order loop and a 8 Ms/s sampling rate.

It uses just basic models like voltage controlled voltage sources.

If this is of any help let me know.

Regards

Charles
  Reply With Quote
Old 3rd November 2007, 08:49 PM   #9
d1983 is offline d1983  Canada
diyAudio Member
 
Join Date: Mar 2007
phase_accurate :
That would be so great! I would definitely appreciate that! would you like to email it to me, or what's best?
  Reply With Quote
Old 4th November 2007, 01:04 PM   #10
Gorilla is offline Gorilla  United Kingdom
diyAudio Member
 
Join Date: Jan 2004
Location: London
Analog's AD7400 or AD7401 output a raw 2nd order stream.

The 16-bit rating they are given is from AFAIK the decimation filter they use for performance analysis in the datasheet.
  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
Sigma Delta Bandwidth d1983 Class D 1 14th November 2007 02:17 AM
Nth Order Sigma-Delta Tim__x Class D 30 21st July 2005 04:08 PM
Delta-Sigma Class D contitek Class D 16 10th March 2005 12:10 PM
How does a delta sigma DAC work? Bricolo Digital Source 21 5th June 2003 05:29 PM


New To Site? Need Help?

All times are GMT. The time now is 07:30 AM.


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