TLV320AIC3204 Adaptive Filtering

Jerry Chu

Genius 4915 points

Other Parts Discussed in Thread: TLV320AIC3204EVM-K

Hi,

I am adjusting CS's adaptive filtering and the setting as below list. It won't affect the 500Hz audio.

( BQ1 or BQ2, Gain=10, Q=1 ,Filter Type=EQ, Shelf Response=Treble, Fc=10K)

But when I used the same setting in BQ4 or 5. It will affect the 500Hz audio.

Do you know it?

over 9 years ago

0 Matthew Beardsworth over 9 years ago

TI__Genius 9175 points

Hello,

How are you verifying that it is affecting the 500Hz?

Regards,

-Matt

0 Jerry Chu over 9 years ago in reply to Matthew Beardsworth

Genius 4915 points

Hi Matt,

I set the AIC3204 to be a loop back device. I used iPHONE5 for the audio generator and into AIC3204 IN1L/R. The sine wave is 500Hz. AIC3204 HP output is into my Notebook and used the recorder software to check the audio level.

0 Matthew Beardsworth over 9 years ago in reply to Jerry Chu

TI__Genius 9175 points

Hi,

Have you tried looking at the output on an osciloscope?

We will look into this.

Matt

0 Jerry Chu over 9 years ago in reply to Matthew Beardsworth

Genius 4915 points

Hi Matt,

I provided the TLV320AIC3254EVM-U for my customer and I tested TLV320AIC3204EVM-K. Both are same result. Do you mean we should try to use extra OSC test it again? Thanks!

0 Matthew Beardsworth over 9 years ago in reply to Jerry Chu

TI__Genius 9175 points

Hi Jerry,

Can you send me the script for the TLV320AIC3204EVM-K you are using?

Also what program are you using to monitor the output voltage?

I want to get it up and running to see if I can recreate your setup then go from there.

-Matt

0 Matthew Beardsworth over 9 years ago in reply to Matthew Beardsworth

TI__Genius 9175 points

Hi Jerry,

So I got the board up and working using the CS software. I ran a simple test where I downloaded a 500Hz signal tone and played it off my computer through the headphone out. Using the “Adaptive Filtering” GUI in CS, I set all BQ filters (BQ1-5) at 10KHz. I then set a “reference output” of 100mV AC into a 16 ohm load with all filters set at 0dB.

I then adjusted the attenuation of each filter to measure the output.

Here are the results:

There is very slight attenuation for all 5 of the BQ filters with a 500Hz tone when Q = 1. When Q = 20, there is no attenuation at 500Hz which makes sense. The smaller the Q, the more it will affect other frequencies outside of the Fc cutoff frequency.

Also, you can see that all of the filters at +15dB or -15dB simultaneously have a greater effect since their response adds.

Is this what you are seeing?

Regards,

Matt

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TLV320AIC3204 Adaptive Filtering