TPA3121 problems

Cyberzim · 14th January 2010, 11:26 PM

Hello,
I have attemped to make a pcb for tpa3121, but not with success.
So I would be very happy if you maybe could find some errors in my design.
My first attempt at making the board went very well, no shorts at all and everything was connected where they should. The only problem was, that the amplifier almost gave me none output. You could hear little of the music, so I measured the voltage on the pin called "High voltage power supply" and it was zero, so while it was turned on, I just made with a connection with a wire from positive supply to the pins and then it died

I have one last try, so I will post datasheets and pcblayout and cross my fingers for, that you can help me with this problem.

PCB: Imageshack.dk
Datasheets: http://focus.ti.com/lit/ds/symlink/tpa3121d2.pdf

Regards,

Simon H.A.

m-tech · 09:08 AM

Looking at picture everything is OK but, can you show us your pcb ? Some connections are very close to each other so you might have unwanted short's.
What is "High voltage power supply" ?
AVCC and PVCC should be connected to same power supply. If they are not you need to think about mute and shutdown pin because they have compliance to AVCC.

Cyberzim · 15th January 2010, 09:07 AM

When I get home form school, I will upload a picture of the board.

Regards,

Simon H.A.

Cyberzim · 15th January 2010, 10:10 AM

I will also make a new board with more spacing between the connections to be more sure, that there will be no short circuits.

Cyberzim · 15th January 2010, 05:50 PM

Here is the picture of the board.
I have reconized that the copper gets miscolored from my fluxpen, is there a way to remove it without harming the components?

Imageshack.dk

Regards,

Simon H.A.

theAnonymous1 · 15th January 2010, 06:52 PM

You should really try and clean the flux off the board, it's a bit of a mess.

Cyberzim · 15th January 2010, 06:53 PM

It's water soluble, can I just use that for cleaning the board?

theAnonymous1 · 15th January 2010, 06:55 PM

I would use distilled if possible, and get in there around the chip with a toothbrush. Make sure it's completely dry before powering it up.

No isopropyl alcohol or acetone around?

Pano · 15th January 2010, 07:14 PM

If you use alcohol, use the good stuff. It seems that all you can get in the drug store and supermarkets now in the US is 70%. Doesn't work worth a darn.

The stuff that comes in a can at the hardware store is much better. Don't know what they sell in Danmark.

Cyberzim · 15th January 2010, 07:15 PM

I have 93% at my home, so that should do it.

Regards,

Simon H.A.

14th January 2010, 11:26 PM	#1
Cyberzim diyAudio Member Join Date: Apr 2009 Location: Gentofte	TPA3121 problems Hello, I have attemped to make a pcb for tpa3121, but not with success. So I would be very happy if you maybe could find some errors in my design. My first attempt at making the board went very well, no shorts at all and everything was connected where they should. The only problem was, that the amplifier almost gave me none output. You could hear little of the music, so I measured the voltage on the pin called "High voltage power supply" and it was zero, so while it was turned on, I just made with a connection with a wire from positive supply to the pins and then it died I have one last try, so I will post datasheets and pcblayout and cross my fingers for, that you can help me with this problem. PCB: Imageshack.dk Datasheets: http://focus.ti.com/lit/ds/symlink/tpa3121d2.pdf Regards, Simon H.A.

15th January 2010, 09:05 AM	#2
m-tech diyAudio Member Join Date: Feb 2006 Location: Belgrade	Looking at picture everything is OK but, can you show us your pcb ? Some connections are very close to each other so you might have unwanted short's. What is "High voltage power supply" ? AVCC and PVCC should be connected to same power supply. If they are not you need to think about mute and shutdown pin because they have compliance to AVCC. Last edited by m-tech; 15th January 2010 at 09:08 AM.

15th January 2010, 06:52 PM	#6
theAnonymous1 diyAudio Member Join Date: Feb 2004 Location: Anonymityville	You should really try and clean the flux off the board, it's a bit of a mess. __________________ "If you don't like funerals don't kick sand in Ninja's face." - Ninja

15th January 2010, 06:55 PM	#8
theAnonymous1 diyAudio Member Join Date: Feb 2004 Location: Anonymityville	I would use distilled if possible, and get in there around the chip with a toothbrush. Make sure it's completely dry before powering it up. No isopropyl alcohol or acetone around? __________________ "If you don't like funerals don't kick sand in Ninja's face." - Ninja

15th January 2010, 07:14 PM	#9
Pano diyAudio Moderator Join Date: Oct 2004 Location: North Carolina Blog Entries: 4	If you use alcohol, use the good stuff. It seems that all you can get in the drug store and supermarkets now in the US is 70%. Doesn't work worth a darn. The stuff that comes in a can at the hardware store is much better. Don't know what they sell in Danmark. __________________ Take the Speaker Voltage Test!


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15th January 2010, 09:07 AM	#3
Cyberzim diyAudio Member Join Date: Apr 2009 Location: Gentofte	When I get home form school, I will upload a picture of the board. Regards, Simon H.A.

15th January 2010, 10:10 AM	#4
Cyberzim diyAudio Member Join Date: Apr 2009 Location: Gentofte	I will also make a new board with more spacing between the connections to be more sure, that there will be no short circuits.

15th January 2010, 05:50 PM	#5
Cyberzim diyAudio Member Join Date: Apr 2009 Location: Gentofte	Here is the picture of the board. I have reconized that the copper gets miscolored from my fluxpen, is there a way to remove it without harming the components? Imageshack.dk Regards, Simon H.A.

15th January 2010, 06:53 PM	#7
Cyberzim diyAudio Member Join Date: Apr 2009 Location: Gentofte	It's water soluble, can I just use that for cleaning the board?

15th January 2010, 07:15 PM	#10
Cyberzim diyAudio Member Join Date: Apr 2009 Location: Gentofte	I have 93% at my home, so that should do it. Regards, Simon H.A.

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