CC3200AUDBOOST: noise issue in audio codec

charusingh21

Part Number: CC3200AUDBOOST
Other Parts Discussed in Thread: TPA2012D2, TLV320AIC3254, , TPA2012D2EVM

Hi,

I was trying the wifi audio example and was able to transmit my audio data from one board to other. But the problem is when I tried with the 1kHz clean sine wave as input ,I can hear the sound very clear without any noise but when I checked on oscilloscope it shows that there is some kind of noise present which is may be imperceptible to human ear. I tried using external power supply but still the result is same. I read about common noise issues in audio codec and according it I should put low pass filter (1kohm resistor and 4,7nF cap) after codec but its not possible as I cannot track the path on the board . Can I put the low pass filter after the class D power amplifier at the output of speaker? Will it help?

Regards,

Charu

over 5 years ago

0 Chris Sterzik over 5 years ago

TI__Guru 53525 points

In order to help you track the path on the board, please refer to the documentation here: www.ti.com/.../tidc-cc3200audboost . The design files are available. I will ask the amplifier team to comment on the placement of the filter.

Regards,
Chris

0 Tom Hendrick over 5 years ago in reply to Chris Sterzik

TI__Guru**** 168485 points

Hi Charu,

By the TPA2012D2 datasheet, you can filter the outputs of the amplifier before the speakers. By the schematic for the CC3200AUDBOOST, they have 1K and 4.7nF filters in place between the TLV320AIC3254 and the amplifier already.

0 charusingh21 over 5 years ago in reply to Tom Hendrick

Intellectual 480 points

Hi Tom,

Thanks for the reply. Can you please suggest me on how to filter the outputs of the amplifier before the speakers as the noise is not audible but is there.

Regards,

Charu

0 Tom Hendrick over 5 years ago in reply to charusingh21

TI__Guru**** 168485 points

If you review the TPA2012D2EVM, they use ferrite beads and capacitors as a filter - the details are in the Users Guide, section 3.3, Table 2.

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CC3200AUDBOOST: noise issue in audio codec