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TLV320AIC23B: TLV320AIC23BIPWR - Need for Anti-Aliasing on ADC input and Reconstruction on DAC output?

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Replies: 4

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Part Number: TLV320AIC23B

Hello,

I am trying to use the TLV320AIC23BIPWR Codec with a dynamic microphone and a piano amplifier. For the input to the ADC, I figured an anti-aliasing filter couldn't hurt the signal processing in the Codec.

However, I was not as sure about the DAC output. Does anyone know if the signal needs to be reconstructed at the output of the DAC or whether that is included in the Codec?

Also, I hadn't been able to find the voltage limits for the MODE pin in the datasheet.

Any information on either would be greatly appreciated. Thank you for the support in advance.

Best regards,

Laura

  • Hello Laura,

    The output of the Audio DAC is an analog signal and does not need to be "reconstructed" (like a PWM output would).  That said, the delta-sigma audio dac architecture purposely pushes a lot of the signal noise out of the audio band resulting in some higher frequency noise you'll want to filter out.  Therefore, for best performance you'll want an external anti-aliasing filter to reduce the out-of-band noise from folding back into the audio band.

    Regards,
    Collin Wells
    Precision ADC Applications

  • Hello Laura,

    For the first question, I am not quite sure about this and may need to do some digging. This device is on the older side and some information can be a bit difficult to find. A question I have is why not use a device like the AIC3104 or AIC3106? These codecs were developed more recent that the AIC23 and have an integrated anti-aliasing and reconstruction filter. 

    To answer the mode pin question, I believe this pin should be pulled to DVDD for high and GND for LOW. 

    Regards,

    Aaron

  • In reply to Collin Wells:

    Thank you so much for this document and looking into the Codec! The document you sent has already been helpful.

    Thanks again!

    Laura

  • In reply to Aaron Estrada51:

    Hi Aaron,

    The newer ones have more capabilities than we need as we are only using the Codec for two inputs to the ADC and one output from the DAC. We decided to anti-aliasing outside the Codec would work for our needs. I did look into the newer devices and they might be helpful for future projects. 

    Thank you for your answer about the MODE pin! 

    Regards,

    Laura