TPA3123 add audio transformer issue

Hi Don:

Thank you very much for your reply.  I also have a question when we add transformer on my schematic whether it means I have add a new inductance on my out put. Whether we should add resistance parallel connection or series connection on transformer? I have add 4ohm resistance on it , but it hasn't any improve.

Hi, Knight,

In our limited experience, this does not seem necessary.

-d2

Hi Don Dapkus:

I have solved the problem of add transformer. Thank you very much!

But I have also found that, the out put waveform also have 250K noise wave on my 20K output wave form. I have test some low-pass filter for TPA3123 output, and the noise wave is still on my output wave form. Can you give me some advice?

Hi Don Dapkus:

I also have a problem about TPA3123 Signal-to-noise ratio, datasheet said that TPA3123 Signal-to-noise ratio will reach 99dB. But my test result is only 30dB.

Can you share the test method of TPA3123 Signal-to-noise ratio?

Hi Don & Knight Yu,

I have the same issue when I add audio transformer at the TPA3123 SE output.

Could you share me your suggestion and solution?

Thanks.

Regards,

Eddie

Hi, Eddie,

Unfortunately, we don't have a lot of experience with transformer-coupled audio. 

It might be interesting if Knight can share his experience. He can't share a lot of details since those are customer proprietary, but maybe he can at least say they were successful in using this part to drive a transformer.

-d2

Hi Knight Yu,

could you share information about your solution in connecting the output transformer ? I am presently working on a TAS5611A.

Thanks in advance,

Enrico