topology similar to BCA - diyAudio
Go Back   Home > Forums > Amplifiers > Class D
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 15th July 2009, 08:09 PM   #1
81bas is offline 81bas  Germany
diyAudio Member
Join Date: Jan 2006
Location: Kiel
Default topology similar to BCA


Simulated the following schematics (in attachment) in LTspice. It is very similar to BCA topology in first look, but works others. Mosfets are switched in antiphase - similar to usual class d output stage (had no spice model for IR2110, so had to build own driver ). Output inductors are on the _same_ core. There is no dead time at all. Even little bias required to avoid distortions. Advantage is that body diode does not limits the dV/dt of opposite mosfet. Also, usual halfbridge driver can be used here. I have not built it yet, but simulation does not shows any problems. Don't know, where I have seen this.
Any thoughts?
Attached Images
File Type: gif classd.gif (12.0 KB, 452 views)
  Reply With Quote
Old 15th July 2009, 10:25 PM   #2
Pafi is offline Pafi  Hungary
diyAudio Member
Join Date: May 2004
Location: Budapest

I'd say this is BCA topology yet, only different modulation. Output inductors can be on the same core, but they have to be coupled weakly. I've built this some years ago, it works fine.

In reality I had a little trouble with dead-time, because I used IR2110 to drive 140 nC gate-charge with Vcc=12V, and it could switch the mosfets on almost immediately, but gate discharge needed much more time, so I had to make a little dead-time, wich was not so easy since I haven't prepared the PCB for this.
  Reply With Quote
Old 21st July 2009, 03:20 PM   #3
diyAudio Moderator Emeritus
lumanauw's Avatar
Join Date: Oct 2002
Location: Bandung
Send a message via Yahoo to lumanauw
What happen if the inductors are separated / not on the same core?

What is the purpose of R1=100ohm?
  Reply With Quote
Old 22nd July 2009, 09:08 PM   #4
81bas is offline 81bas  Germany
diyAudio Member
Join Date: Jan 2006
Location: Kiel

Sorry for the long silence... had no possibility to simulate and investigate this more precisely...

Now I have tried various configurations with this schematics. There is no practical purpose of R1, as I found from simulations. Also, when L1/L2 are not on the same core, then opposite side periodically goes into free wheeling state (i.e. has no any current). This causes a big distortions then. In attached image the blue line is the input signal (corrected in phase) and yellow is output signal from NOT coupled variant.
Attached Images
File Type: jpg not_coupled.jpg (28.6 KB, 280 views)
  Reply With Quote
Old 10th September 2014, 09:37 AM   #5
diyAudio Member
Workhorse's Avatar
Join Date: Dec 2004
Have you taken into consideration the circulated currents in the freewheeling diodes with this topology?
  Reply With Quote


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
C37 similar material tube-lover Multi-Way 27 22nd July 2013 06:14 PM
ZRT 2.5 in TL enclosure or similar ST7677 Multi-Way 14 29th September 2008 10:44 PM
similar to SKA djk Solid State 6 7th June 2007 03:28 PM
looking for similar FET Ahmad_tbp Solid State 5 6th May 2006 09:26 PM
Similar DC/DC coverters? eeka chu Digital Source 1 20th April 2004 08:49 AM

New To Site? Need Help?

All times are GMT. The time now is 12:30 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2