Go Back   Home > Forums > >

Class D Switching Power Amplifiers and Power D/A conversion

TPA3251d2
TPA3251d2
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
Old 6th July 2016, 10:46 PM   #1001
Eldam is offline Eldam  France
Banned
 
Join Date: Sep 2012
Location: France
Btw, where can we find Dr M. 3521 pcb offer ? (be it populated or not)...,? I have not been following the thread lately !
  Reply With Quote
Old 6th July 2016, 10:51 PM   #1002
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
@cloud, did you got your boards up and running?
  Reply With Quote
Old 6th July 2016, 11:28 PM   #1003
cloud1972 is offline cloud1972  United Kingdom
diyAudio Member
 
Join Date: Sep 2014
yes one of them still not put it in case and using a 32v smps of poor quality and yet im still very impressed with the sound considering i have only had 5 hours of listening i have a feeling it will replace my trupath ta3020 in my system waiting for connexelectronic power supply then it's time to make it really sing
do you think a LDR pre amp stage would make a good partner for this build?

Last edited by cloud1972; 6th July 2016 at 11:29 PM. Reason: spell mistake
  Reply With Quote
Old 7th July 2016, 08:41 PM   #1004
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
Never used an LDR stage.
  Reply With Quote
Old 3rd August 2016, 12:04 AM   #1005
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
Finally managed to get my case done.

TPA3251 (TPA3255) aka ?Model Tiny? in Aluminiumgehäuse ? #360customs

TPA3251 "Model Tiny":

Class D Amp Photo Gallery-img_8844_1200-jpg

Class D Amp Photo Gallery-img_8838_1200-jpg

Class D Amp Photo Gallery-img_8849_1200-jpg

Hope to get the revision done on the blue board soon to order some new boards. (Finally for the DIYers)
  Reply With Quote
Old 3rd August 2016, 12:54 AM   #1006
easp is offline easp
diyAudio Member
 
Join Date: May 2016
Nice, Doctormord!

I'm curious about the thermal bridge. I've seen the photos on your site, but I'm not clear on a few things. Is there just one? Is it affixed to the case, or the board/chip? Is there just one silicone pad? You refer to the plates as "soldered" do you solder them to the top of the chip, or did you build them up be soldering together thinner sheets?

Thanks.
  Reply With Quote
Old 3rd August 2016, 01:11 AM   #1007
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
Thanks for the question. The heat bridge consists of 3 copper sheets which are polished first and then soldered together by reflow and solder paste. This then gets connected to the case by the thin thermal pad as the case isn't that flat due to the manufacturing process of extruding. The thermal connection between the 3251's thermal pad and the heat bridge is just "press fit" without any grease as the thin top copper sheet is rather soft.

Doing so, the heat bridge sits straight and tight on the 3251's top pad with minimal thermal resistance, any non-flatness is carried out by the thermal pad.

The solution is able to handle 100Wrms (or 2x50Wrms) continuous output power at 30°C ambient. Thermal flow is quite good as the case is heating up quickly to about 60°C. With an efficiency of 90% there's 10W thermal loss at 100W output power, so the solution is at ~3K/W. When listening to music higher output power isn't a problem due to "burst"/crest factor.

The only limiting factor then is the inductors saturation current limit at ~8A.

Last edited by doctormord; 3rd August 2016 at 01:19 AM.
  Reply With Quote
Old 3rd August 2016, 01:23 AM   #1008
easp is offline easp
diyAudio Member
 
Join Date: May 2016
Cool, thanks for the details!
  Reply With Quote
Old 3rd August 2016, 03:37 AM   #1009
Kindhornman is offline Kindhornman  United States
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
TPA3251d2
doctoemord are you selling the small boards or just the larger boards to diy'ers. I would love to get a pair of boards to go with some prototype work I am doing. It will be one part of a development project using the ADAU1701 chip.

Thank you,
Steven
  Reply With Quote
Old 16th August 2016, 01:03 PM   #1010
jencelo is offline jencelo  United States
diyAudio Member
 
Join Date: May 2009
@doctormord: Do you have any update on the amps/boards? Thanks.
  Reply With Quote

Reply


TPA3251d2Hide this!Advertise here!
Thread Tools

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


New To Site? Need Help?

All times are GMT. The time now is 03:37 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki