Rebuilt my old Tripath TA0104-based ampifier - Page 2 - 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 20th February 2009, 01:07 PM   #11
Luco is offline Luco  Italy
diyAudio Member
 
Join Date: Feb 2009
Default EMI problem with Tripath

Hi
i'm still having a RF prob with TAA4100A and 41Hz PCB layout (AMP9).
I built an omnidirectional amplified sound source for room-acoustics measurments controlled by an FM module at 433.9 MHz that I use to turn on/off the ampli.
RF emitted by tripath interferes with FM module and makes it not working. With traditional class AB amplifier instead I have no problems.
I look with a spectrum analyzer and a biconic antenna near the amp, but no RF is produced at 433.9 by tripath, while a big amount of RF is produced from 60 to 300 MHz.
I tryed to random put any big ferrites at the outputs and I improved a little the working distance..
Do you have any other suggestions to solve my problem?
  Reply With Quote
Old 20th February 2009, 05:55 PM   #12
jahonen is offline jahonen  Finland
diyAudio Member
 
jahonen's Avatar
 
Join Date: Jan 2002
Location: Kuopio, Finland
Hi Luco,

My standard advice would be that add more ground layers to your PCB but in this case that would not be very practical.

Only effective way to get rid of that common-mode EMI you are experiencing is to put that amplifier into shielded box and running all the wires through feedthrough capacitors. Once created, this type of EMI is painstakingly difficult to get rid of.

Without I/O-filtering, the shielding box is quite useless, as the radiator are the wires connected to the amplifier. The amplifier just provides the RF voltage what makes the wires radiate. I guess that EMI-levels drop if cables are disconnected. When you put the ferrites in the cables, common-mode currents are reduced and EMI levels drop.

Regards,
Janne
  Reply With Quote
Old 21st February 2009, 02:40 PM   #13
Luco is offline Luco  Italy
diyAudio Member
 
Join Date: Feb 2009
thank you Janne,

why do you think not pratical a 4 layers pcb?
I verifyed, as you say, that most radiated EM comes from input and mostly output wires.
I also tryed to twist output cables before loudspeakers, but nothing changed.
  Reply With Quote
Old 21st February 2009, 06:10 PM   #14
jahonen is offline jahonen  Finland
diyAudio Member
 
jahonen's Avatar
 
Join Date: Jan 2002
Location: Kuopio, Finland
Quote:
Originally posted by Luco
thank you Janne,

why do you think not pratical a 4 layers pcb?
I verifyed, as you say, that most radiated EM comes from input and mostly output wires.
I also tryed to twist output cables before loudspeakers, but nothing changed.
Yes, it is very practical (actually, much more practical than full EMI-containment) if you can take the afford it needs to re-design the board and of course, it costs a little more than double-sided PCB. But the results are usually worth it. I just thought that is something you don't want to do.

However, if you anyway do, then assign one layer to contiguous ground plane. Then place all high edge rate and power feeds signals next to this plane. And placing all the external connection points close to each other reduces common mode difference between them, reducing emissions further. Though that was not problem with my TA0104 design.

Regards,
Janne
  Reply With Quote
Old 23rd February 2009, 01:37 PM   #15
diyAudio Member
 
Join Date: Dec 2008
Default Class T TA0102A module

Hello, I am new to this site and first want to say hello to everyone and give a little info of my electronics background. I have 2 degrees in electronics, 1 for an electronics tech and 1 for an electronic engineer so I have knowledge of electronics. That being said I would like to ask, any one who can tell me,
what exactly is this module in a class T amp. Also I don't have experience in class T amps yet so I need all the knowledge I can get. I buy broken car amps and some working ones, depending what kind they are. I repair them and resale them or keep which ever ones I like cause I also collect car amps. I have about 62 of them. been collecting for years, older ones and some newer ones from the mid 1980's to now. Anyway I bought a Clarion car amp and opened it up and seen this big black square looking module thing and it says Tripath TA0102A, but now all I know it's called a module. Well I found a bad zener diode and now the amp turns on but no audio output. No nothing from the speaker terminals when an input signal is applied. No current draw at all and all transistors are good, the power supply transistors and output transitors are all fine as well. so I am wondering if this module can burnout easily and create this problem of no output signal and also what it does. Please let me know as soon as anyone can. Thank you
  Reply With Quote
Old 23rd February 2009, 03:52 PM   #16
diyAudio Member
 
theAnonymous1's Avatar
 
Join Date: Feb 2004
Location: Anonymityville
The module contains the Tripath DPP IC and the hi and low MOSFET drivers. These modules tend to die an undignified death if any of the output MOSFETs go bad. They don't seem to have any internal protections in this regard. They are not serviceable.

Inside the module
  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
A Tripath TA3020 based amp ehien Class D 48 27th July 2010 03:55 PM
WTB: Tripath TA0104 Module laugoo Swap Meet 1 21st July 2008 03:48 AM
Tripath TA0104 Eval Board Problem - Help! laugoo Class D 0 2nd June 2008 06:06 AM
FS: 3 Tripath TA0104 eval boards and PS parts guyv Swap Meet 4 25th December 2007 07:34 AM
Tripath TA0104 board - wanna buy blmn Swap Meet 2 9th March 2006 08:23 PM


New To Site? Need Help?

All times are GMT. The time now is 04:02 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