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 31st January 2016, 05:48 PM   #601
gmarsh is offline gmarsh  Canada
diyAudio Member
 
gmarsh's Avatar
 
Join Date: Apr 2004
Location: Halifax, NS
Finally got a couple hours to spend on the TPA3250D2 card.

Click the image to open in full size.

Breakout's figured out, going for the same "stupidly low power supply Z" strategy as the Wiener card. With the heatsink no longer on the card, I've got all this extra room, trying to figure out what to do with it. Probably gonna shrink the card a little, right now it's 8x12cm.
  Reply With Quote
Old 2nd February 2016, 01:56 PM   #602
impuls60 is offline impuls60  Norway
diyAudio Member
 
Join Date: Apr 2011
Nice! Is the AVDD pin 9 on this comparable in function to the tpa3116 pin 17? If so which RC values are you going for for hiss dampening? My experienses with the tpa3116 is that higher values than recommended (10R 1uF) works a lot better.
  Reply With Quote
Old 3rd February 2016, 12:44 AM   #603
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
There's actually no hiss at the 3251 as the AVDD is generated separately, so PSRR (normally) is way better on this rail until you set the system voltage so low that the regulators get into dropout.

I did a short test with the new heatsinks+fan for the small boards mounted on the (bigger) blue board. Without fan it seems that the amp will run "forever" with music program. (Set to light clipping, tested with Drum n Bass -> small crest factor)

Haven't tested for longer period of time as my load resistors desoldered.

Output power (both channels) was at an average of 100W with bursts at 250W.

(But: free air, 20C ambient, bigger pcb)
  Reply With Quote
Old 3rd February 2016, 12:45 PM   #604
impuls60 is offline impuls60  Norway
diyAudio Member
 
Join Date: Apr 2011
Nice that TI upgraded the AVDD feature! The hiss on the 3116 chip is quite annoying for nearfield use. Doctormord, have you noiticed any distinct tonality differences between 3316 and 3251? I guess they would be similar but isn't the 3251 supposed to be more advanced?
  Reply With Quote
Old 3rd February 2016, 02:29 PM   #605
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
Can't tell as i never heard a "chinese made" 3116 board. My 3132 board (which is a 3116 in qfn package) does not hiss.

Spec-wise, the 3251 is (a magnitude) better than the older generation 31XX ics.

For the AVDD, it's a total different story, as the 3151 has "virtually" no input stage. (Just 20dB inverting amplifier per channel, where the 3116 got a PGA and Diffamp)
So care must be taken in design of the "dicrete" analog frontend feeding the 3251.

PCBs are in the mail. (should arrive in 3 weeks i guess)

TPA3251d2-28766-jpg
Attached Images
File Type: jpg 28766.jpg (98.0 KB, 791 views)

Last edited by doctormord; 3rd February 2016 at 02:33 PM.
  Reply With Quote
Old 3rd February 2016, 10:23 PM   #606
noah katz is offline noah katz  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Mountain View, CA
Quote:
Originally Posted by doctormord View Post
Output power (both channels) was at an average of 100W with bursts at 250W.
What voltage and impedance gave 250W?
__________________
-----------------------------------------
Noah
  Reply With Quote
Old 3rd February 2016, 10:51 PM   #607
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
Default TPA3251d2

PVCC=36V, 4R load.

Both channels combined.
  Reply With Quote
Old 4th February 2016, 01:42 AM   #608
noah katz is offline noah katz  United States
diyAudio Member
 
Join Date: Jul 2004
Location: Mountain View, CA
Ah, thanks
__________________
-----------------------------------------
Noah
  Reply With Quote
Old 4th February 2016, 12:06 PM   #609
Eldam is offline Eldam  France
Banned
 
Join Date: Sep 2012
Location: France
Hello DrMord,

Do you plan a pins plug with strap to swap from BLT to PBLT mode ?
  Reply With Quote
Old 4th February 2016, 12:53 PM   #610
doctormord is offline doctormord  Germany
diyAudio Member
 
doctormord's Avatar
 
Join Date: Oct 2007
It's configured by solder jumpers.
  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 06:03 PM.


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